pg_hint_plan.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pg_hint_plan.c
   4  *                hinting on how to execute a query for PostgreSQL
   5  *
   6  * Copyright (c) 2012-2019, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
   7  *
   8  *-------------------------------------------------------------------------
   9  */
  10 #include <string.h>
  11
  12 #include "postgres.h"
  13 #include "access/genam.h"
  14 #include "access/heapam.h"
  15 #include "access/relation.h"
  16 #include "catalog/pg_collation.h"
  17 #include "catalog/pg_index.h"
  18 #include "commands/prepare.h"
  19 #include "mb/pg_wchar.h"
  20 #include "miscadmin.h"
  21 #include "nodes/nodeFuncs.h"
  22 #include "nodes/params.h"
  23 #include "optimizer/appendinfo.h"
  24 #include "optimizer/clauses.h"
  25 #include "optimizer/cost.h"
  26 #include "optimizer/geqo.h"
  27 #include "optimizer/joininfo.h"
  28 #include "optimizer/optimizer.h"
  29 #include "optimizer/pathnode.h"
  30 #include "optimizer/paths.h"
  31 #include "optimizer/plancat.h"
  32 #include "optimizer/planner.h"
  33 #include "optimizer/prep.h"
  34 #include "optimizer/restrictinfo.h"
  35 #include "parser/analyze.h"
  36 #include "parser/parsetree.h"
  37 #include "parser/scansup.h"
  38 #include "partitioning/partbounds.h"
  39 #include "tcop/utility.h"
  40 #include "utils/builtins.h"
  41 #include "utils/lsyscache.h"
  42 #include "utils/memutils.h"
  43 #include "utils/rel.h"
  44 #include "utils/snapmgr.h"
  45 #include "utils/syscache.h"
  46 #include "utils/resowner.h"
  47
  48 #include "catalog/pg_class.h"
  49
  50 #include "executor/spi.h"
  51 #include "catalog/pg_type.h"
  52
  53 #include "plpgsql.h"
  54
  55 /* partially copied from pg_stat_statements */
  56 #include "normalize_query.h"
  57
  58 /* PostgreSQL */
  59 #include "access/htup_details.h"
  60
  61 #ifdef PG_MODULE_MAGIC
  62 PG_MODULE_MAGIC;
  63 #endif
  64
  65 #define BLOCK_COMMENT_START             "/*"
  66 #define BLOCK_COMMENT_END               "*/"
  67 #define HINT_COMMENT_KEYWORD    "+"
  68 #define HINT_START                              BLOCK_COMMENT_START HINT_COMMENT_KEYWORD
  69 #define HINT_END                                BLOCK_COMMENT_END
  70
  71 /* hint keywords */
  72 #define HINT_SEQSCAN                    "SeqScan"
  73 #define HINT_INDEXSCAN                  "IndexScan"
  74 #define HINT_INDEXSCANREGEXP    "IndexScanRegexp"
  75 #define HINT_BITMAPSCAN                 "BitmapScan"
  76 #define HINT_BITMAPSCANREGEXP   "BitmapScanRegexp"
  77 #define HINT_TIDSCAN                    "TidScan"
  78 #define HINT_NOSEQSCAN                  "NoSeqScan"
  79 #define HINT_NOINDEXSCAN                "NoIndexScan"
  80 #define HINT_NOBITMAPSCAN               "NoBitmapScan"
  81 #define HINT_NOTIDSCAN                  "NoTidScan"
  82 #define HINT_INDEXONLYSCAN              "IndexOnlyScan"
  83 #define HINT_INDEXONLYSCANREGEXP        "IndexOnlyScanRegexp"
  84 #define HINT_NOINDEXONLYSCAN    "NoIndexOnlyScan"
  85 #define HINT_PARALLEL                   "Parallel"
  86
  87 #define HINT_NESTLOOP                   "NestLoop"
  88 #define HINT_MERGEJOIN                  "MergeJoin"
  89 #define HINT_HASHJOIN                   "HashJoin"
  90 #define HINT_NONESTLOOP                 "NoNestLoop"
  91 #define HINT_NOMERGEJOIN                "NoMergeJoin"
  92 #define HINT_NOHASHJOIN                 "NoHashJoin"
  93 #define HINT_LEADING                    "Leading"
  94 #define HINT_SET                                "Set"
  95 #define HINT_ROWS                               "Rows"
  96
  97 #define HINT_ARRAY_DEFAULT_INITSIZE 8
  98
  99 #define hint_ereport(str, detail) hint_parse_ereport(str, detail)
 100 #define hint_parse_ereport(str, detail) \
 101         do { \
 102                 ereport(pg_hint_plan_parse_message_level,               \
 103                         (errmsg("pg_hint_plan: hint syntax error at or near \"%s\"", (str)), \
 104                          errdetail detail)); \
 105         } while(0)
 106
 107 #define skip_space(str) \
 108         while (isspace(*str)) \
 109                 str++;
 110
 111 enum
 112 {
 113         ENABLE_SEQSCAN = 0x01,
 114         ENABLE_INDEXSCAN = 0x02,
 115         ENABLE_BITMAPSCAN = 0x04,
 116         ENABLE_TIDSCAN = 0x08,
 117         ENABLE_INDEXONLYSCAN = 0x10
 118 } SCAN_TYPE_BITS;
 119
 120 enum
 121 {
 122         ENABLE_NESTLOOP = 0x01,
 123         ENABLE_MERGEJOIN = 0x02,
 124         ENABLE_HASHJOIN = 0x04
 125 } JOIN_TYPE_BITS;
 126
 127 #define ENABLE_ALL_SCAN (ENABLE_SEQSCAN | ENABLE_INDEXSCAN | \
 128                                                  ENABLE_BITMAPSCAN | ENABLE_TIDSCAN | \
 129                                                  ENABLE_INDEXONLYSCAN)
 130 #define ENABLE_ALL_JOIN (ENABLE_NESTLOOP | ENABLE_MERGEJOIN | ENABLE_HASHJOIN)
 131 #define DISABLE_ALL_SCAN 0
 132 #define DISABLE_ALL_JOIN 0
 133
 134 /* hint keyword of enum type*/
 135 typedef enum HintKeyword
 136 {
 137         HINT_KEYWORD_SEQSCAN,
 138         HINT_KEYWORD_INDEXSCAN,
 139         HINT_KEYWORD_INDEXSCANREGEXP,
 140         HINT_KEYWORD_BITMAPSCAN,
 141         HINT_KEYWORD_BITMAPSCANREGEXP,
 142         HINT_KEYWORD_TIDSCAN,
 143         HINT_KEYWORD_NOSEQSCAN,
 144         HINT_KEYWORD_NOINDEXSCAN,
 145         HINT_KEYWORD_NOBITMAPSCAN,
 146         HINT_KEYWORD_NOTIDSCAN,
 147         HINT_KEYWORD_INDEXONLYSCAN,
 148         HINT_KEYWORD_INDEXONLYSCANREGEXP,
 149         HINT_KEYWORD_NOINDEXONLYSCAN,
 150
 151         HINT_KEYWORD_NESTLOOP,
 152         HINT_KEYWORD_MERGEJOIN,
 153         HINT_KEYWORD_HASHJOIN,
 154         HINT_KEYWORD_NONESTLOOP,
 155         HINT_KEYWORD_NOMERGEJOIN,
 156         HINT_KEYWORD_NOHASHJOIN,
 157
 158         HINT_KEYWORD_LEADING,
 159         HINT_KEYWORD_SET,
 160         HINT_KEYWORD_ROWS,
 161         HINT_KEYWORD_PARALLEL,
 162
 163         HINT_KEYWORD_UNRECOGNIZED
 164 } HintKeyword;
 165
 166 #define SCAN_HINT_ACCEPTS_INDEX_NAMES(kw) \
 167         (kw == HINT_KEYWORD_INDEXSCAN ||                        \
 168          kw == HINT_KEYWORD_INDEXSCANREGEXP ||          \
 169          kw == HINT_KEYWORD_INDEXONLYSCAN ||            \
 170          kw == HINT_KEYWORD_INDEXONLYSCANREGEXP ||      \
 171          kw == HINT_KEYWORD_BITMAPSCAN ||                               \
 172          kw == HINT_KEYWORD_BITMAPSCANREGEXP)
 173
 174
 175 typedef struct Hint Hint;
 176 typedef struct HintState HintState;
 177
 178 typedef Hint *(*HintCreateFunction) (const char *hint_str,
 179                                                                          const char *keyword,
 180                                                                          HintKeyword hint_keyword);
 181 typedef void (*HintDeleteFunction) (Hint *hint);
 182 typedef void (*HintDescFunction) (Hint *hint, StringInfo buf, bool nolf);
 183 typedef int (*HintCmpFunction) (const Hint *a, const Hint *b);
 184 typedef const char *(*HintParseFunction) (Hint *hint, HintState *hstate,
 185                                                                                   Query *parse, const char *str);
 186
 187 /* hint types */
 188 #define NUM_HINT_TYPE   6
 189 typedef enum HintType
 190 {
 191         HINT_TYPE_SCAN_METHOD,
 192         HINT_TYPE_JOIN_METHOD,
 193         HINT_TYPE_LEADING,
 194         HINT_TYPE_SET,
 195         HINT_TYPE_ROWS,
 196         HINT_TYPE_PARALLEL
 197 } HintType;
 198
 199 typedef enum HintTypeBitmap
 200 {
 201         HINT_BM_SCAN_METHOD = 1,
 202         HINT_BM_PARALLEL = 2
 203 } HintTypeBitmap;
 204
 205 static const char *HintTypeName[] = {
 206         "scan method",
 207         "join method",
 208         "leading",
 209         "set",
 210         "rows",
 211         "parallel"
 212 };
 213
 214 /* hint status */
 215 typedef enum HintStatus
 216 {
 217         HINT_STATE_NOTUSED = 0,         /* specified relation not used in query */
 218         HINT_STATE_USED,                        /* hint is used */
 219         HINT_STATE_DUPLICATION,         /* specified hint duplication */
 220         HINT_STATE_ERROR                        /* execute error (parse error does not include
 221                                                                  * it) */
 222 } HintStatus;
 223
 224 #define hint_state_enabled(hint) ((hint)->base.state == HINT_STATE_NOTUSED || \
 225                                                                   (hint)->base.state == HINT_STATE_USED)
 226
 227 static unsigned int qno = 0;
 228 static unsigned int msgqno = 0;
 229 static char qnostr[32];
 230 static const char *current_hint_str = NULL;
 231
 232 /*
 233  * However we usually take a hint stirng in post_parse_analyze_hook, we still
 234  * need to do so in planner_hook when client starts query execution from the
 235  * bind message on a prepared query. This variable prevent duplicate and
 236  * sometimes harmful hint string retrieval.
 237  */
 238 static bool current_hint_retrieved = false;
 239
 240 /* common data for all hints. */
 241 struct Hint
 242 {
 243         const char                 *hint_str;           /* must not do pfree */
 244         const char                 *keyword;            /* must not do pfree */
 245         HintKeyword                     hint_keyword;
 246         HintType                        type;
 247         HintStatus                      state;
 248         HintDeleteFunction      delete_func;
 249         HintDescFunction        desc_func;
 250         HintCmpFunction         cmp_func;
 251         HintParseFunction       parse_func;
 252 };
 253
 254 /* scan method hints */
 255 typedef struct ScanMethodHint
 256 {
 257         Hint                    base;
 258         char               *relname;
 259         List               *indexnames;
 260         bool                    regexp;
 261         unsigned char   enforce_mask;
 262 } ScanMethodHint;
 263
 264 typedef struct ParentIndexInfo
 265 {
 266         bool            indisunique;
 267         Oid                     method;
 268         List       *column_names;
 269         char       *expression_str;
 270         Oid                *indcollation;
 271         Oid                *opclass;
 272         int16      *indoption;
 273         char       *indpred_str;
 274 } ParentIndexInfo;
 275
 276 /* join method hints */
 277 typedef struct JoinMethodHint
 278 {
 279         Hint                    base;
 280         int                             nrels;
 281         int                             inner_nrels;
 282         char              **relnames;
 283         unsigned char   enforce_mask;
 284         Relids                  joinrelids;
 285         Relids                  inner_joinrelids;
 286 } JoinMethodHint;
 287
 288 /* join order hints */
 289 typedef struct OuterInnerRels
 290 {
 291         char   *relation;
 292         List   *outer_inner_pair;
 293 } OuterInnerRels;
 294
 295 typedef struct LeadingHint
 296 {
 297         Hint                    base;
 298         List               *relations;  /* relation names specified in Leading hint */
 299         OuterInnerRels *outer_inner;
 300 } LeadingHint;
 301
 302 /* change a run-time parameter hints */
 303 typedef struct SetHint
 304 {
 305         Hint    base;
 306         char   *name;                           /* name of variable */
 307         char   *value;
 308         List   *words;
 309 } SetHint;
 310
 311 /* rows hints */
 312 typedef enum RowsValueType {
 313         RVT_ABSOLUTE,           /* Rows(... #1000) */
 314         RVT_ADD,                        /* Rows(... +1000) */
 315         RVT_SUB,                        /* Rows(... -1000) */
 316         RVT_MULTI,                      /* Rows(... *1.2) */
 317 } RowsValueType;
 318 typedef struct RowsHint
 319 {
 320         Hint                    base;
 321         int                             nrels;
 322         int                             inner_nrels;
 323         char              **relnames;
 324         Relids                  joinrelids;
 325         Relids                  inner_joinrelids;
 326         char               *rows_str;
 327         RowsValueType   value_type;
 328         double                  rows;
 329 } RowsHint;
 330
 331 /* parallel hints */
 332 typedef struct ParallelHint
 333 {
 334         Hint                    base;
 335         char               *relname;
 336         char               *nworkers_str;       /* original string of nworkers */
 337         int                             nworkers;               /* num of workers specified by Worker */
 338         bool                    force_parallel; /* force parallel scan */
 339 } ParallelHint;
 340
 341 /*
 342  * Describes a context of hint processing.
 343  */
 344 struct HintState
 345 {
 346         char               *hint_str;                   /* original hint string */
 347
 348         /* all hint */
 349         int                             nall_hints;                     /* # of valid all hints */
 350         int                             max_all_hints;          /* # of slots for all hints */
 351         Hint              **all_hints;                  /* parsed all hints */
 352
 353         /* # of each hints */
 354         int                             num_hints[NUM_HINT_TYPE];
 355
 356         /* for scan method hints */
 357         ScanMethodHint **scan_hints;            /* parsed scan hints */
 358
 359         /* Initial values of parameters  */
 360         int                             init_scan_mask;         /* enable_* mask */
 361         int                             init_nworkers;          /* max_parallel_workers_per_gather */
 362         /* min_parallel_table_scan_size*/
 363         int                             init_min_para_tablescan_size;
 364         /* min_parallel_index_scan_size*/
 365         int                             init_min_para_indexscan_size;
 366         int                             init_paratup_cost;      /* parallel_tuple_cost */
 367         int                             init_parasetup_cost;/* parallel_setup_cost */
 368
 369         PlannerInfo        *current_root;               /* PlannerInfo for the followings */
 370         Index                   parent_relid;           /* inherit parent of table relid */
 371         ScanMethodHint *parent_scan_hint;       /* scan hint for the parent */
 372         ParallelHint   *parent_parallel_hint; /* parallel hint for the parent */
 373         List               *parent_index_infos; /* list of parent table's index */
 374
 375         JoinMethodHint **join_hints;            /* parsed join hints */
 376         int                             init_join_mask;         /* initial value join parameter */
 377         List              **join_hint_level;
 378         LeadingHint       **leading_hint;               /* parsed Leading hints */
 379         SetHint           **set_hints;                  /* parsed Set hints */
 380         GucContext              context;                        /* which GUC parameters can we set? */
 381         RowsHint          **rows_hints;                 /* parsed Rows hints */
 382         ParallelHint  **parallel_hints;         /* parsed Parallel hints */
 383 };
 384
 385 /*
 386  * Describes a hint parser module which is bound with particular hint keyword.
 387  */
 388 typedef struct HintParser
 389 {
 390         char                       *keyword;
 391         HintCreateFunction      create_func;
 392         HintKeyword                     hint_keyword;
 393 } HintParser;
 394
 395 /* Module callbacks */
 396 void            _PG_init(void);
 397 void            _PG_fini(void);
 398
 399 static void push_hint(HintState *hstate);
 400 static void pop_hint(void);
 401
 402 static void pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query);
 403 static void pg_hint_plan_ProcessUtility(PlannedStmt *pstmt,
 404                                         const char *queryString,
 405                                         ProcessUtilityContext context,
 406                                         ParamListInfo params, QueryEnvironment *queryEnv,
 407                                         DestReceiver *dest, char *completionTag);
 408 static PlannedStmt *pg_hint_plan_planner(Query *parse, int cursorOptions,
 409                                                                                  ParamListInfo boundParams);
 410 static RelOptInfo *pg_hint_plan_join_search(PlannerInfo *root,
 411                                                                                         int levels_needed,
 412                                                                                         List *initial_rels);
 413
 414 /* Scan method hint callbacks */
 415 static Hint *ScanMethodHintCreate(const char *hint_str, const char *keyword,
 416                                                                   HintKeyword hint_keyword);
 417 static void ScanMethodHintDelete(ScanMethodHint *hint);
 418 static void ScanMethodHintDesc(ScanMethodHint *hint, StringInfo buf, bool nolf);
 419 static int ScanMethodHintCmp(const ScanMethodHint *a, const ScanMethodHint *b);
 420 static const char *ScanMethodHintParse(ScanMethodHint *hint, HintState *hstate,
 421                                                                            Query *parse, const char *str);
 422
 423 /* Join method hint callbacks */
 424 static Hint *JoinMethodHintCreate(const char *hint_str, const char *keyword,
 425                                                                   HintKeyword hint_keyword);
 426 static void JoinMethodHintDelete(JoinMethodHint *hint);
 427 static void JoinMethodHintDesc(JoinMethodHint *hint, StringInfo buf, bool nolf);
 428 static int JoinMethodHintCmp(const JoinMethodHint *a, const JoinMethodHint *b);
 429 static const char *JoinMethodHintParse(JoinMethodHint *hint, HintState *hstate,
 430                                                                            Query *parse, const char *str);
 431
 432 /* Leading hint callbacks */
 433 static Hint *LeadingHintCreate(const char *hint_str, const char *keyword,
 434                                                            HintKeyword hint_keyword);
 435 static void LeadingHintDelete(LeadingHint *hint);
 436 static void LeadingHintDesc(LeadingHint *hint, StringInfo buf, bool nolf);
 437 static int LeadingHintCmp(const LeadingHint *a, const LeadingHint *b);
 438 static const char *LeadingHintParse(LeadingHint *hint, HintState *hstate,
 439                                                                         Query *parse, const char *str);
 440
 441 /* Set hint callbacks */
 442 static Hint *SetHintCreate(const char *hint_str, const char *keyword,
 443                                                    HintKeyword hint_keyword);
 444 static void SetHintDelete(SetHint *hint);
 445 static void SetHintDesc(SetHint *hint, StringInfo buf, bool nolf);
 446 static int SetHintCmp(const SetHint *a, const SetHint *b);
 447 static const char *SetHintParse(SetHint *hint, HintState *hstate, Query *parse,
 448                                                                 const char *str);
 449
 450 /* Rows hint callbacks */
 451 static Hint *RowsHintCreate(const char *hint_str, const char *keyword,
 452                                                         HintKeyword hint_keyword);
 453 static void RowsHintDelete(RowsHint *hint);
 454 static void RowsHintDesc(RowsHint *hint, StringInfo buf, bool nolf);
 455 static int RowsHintCmp(const RowsHint *a, const RowsHint *b);
 456 static const char *RowsHintParse(RowsHint *hint, HintState *hstate,
 457                                                                  Query *parse, const char *str);
 458
 459 /* Parallel hint callbacks */
 460 static Hint *ParallelHintCreate(const char *hint_str, const char *keyword,
 461                                                                 HintKeyword hint_keyword);
 462 static void ParallelHintDelete(ParallelHint *hint);
 463 static void ParallelHintDesc(ParallelHint *hint, StringInfo buf, bool nolf);
 464 static int ParallelHintCmp(const ParallelHint *a, const ParallelHint *b);
 465 static const char *ParallelHintParse(ParallelHint *hint, HintState *hstate,
 466                                                                          Query *parse, const char *str);
 467
 468 static void quote_value(StringInfo buf, const char *value);
 469
 470 static const char *parse_quoted_value(const char *str, char **word,
 471                                                                           bool truncate);
 472
 473 RelOptInfo *pg_hint_plan_standard_join_search(PlannerInfo *root,
 474                                                                                           int levels_needed,
 475                                                                                           List *initial_rels);
 476 void pg_hint_plan_join_search_one_level(PlannerInfo *root, int level);
 477 void pg_hint_plan_set_rel_pathlist(PlannerInfo * root, RelOptInfo *rel,
 478                                                                    Index rti, RangeTblEntry *rte);
 479 static void create_plain_partial_paths(PlannerInfo *root,
 480                                                                                                         RelOptInfo *rel);
 481 static void make_rels_by_clause_joins(PlannerInfo *root, RelOptInfo *old_rel,
 482                                                                           ListCell *other_rels);
 483 static void make_rels_by_clauseless_joins(PlannerInfo *root,
 484                                                                                   RelOptInfo *old_rel,
 485                                                                                   ListCell *other_rels);
 486 static bool has_join_restriction(PlannerInfo *root, RelOptInfo *rel);
 487 static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
 488                                                                    RangeTblEntry *rte);
 489 static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
 490                                                                         Index rti, RangeTblEntry *rte);
 491 RelOptInfo *pg_hint_plan_make_join_rel(PlannerInfo *root, RelOptInfo *rel1,
 492                                                                            RelOptInfo *rel2);
 493
 494 static void pg_hint_plan_plpgsql_stmt_beg(PLpgSQL_execstate *estate,
 495                                                                                   PLpgSQL_stmt *stmt);
 496 static void pg_hint_plan_plpgsql_stmt_end(PLpgSQL_execstate *estate,
 497                                                                                   PLpgSQL_stmt *stmt);
 498 static void plpgsql_query_erase_callback(ResourceReleasePhase phase,
 499                                                                                  bool isCommit,
 500                                                                                  bool isTopLevel,
 501                                                                                  void *arg);
 502 static int set_config_option_noerror(const char *name, const char *value,
 503                                                   GucContext context, GucSource source,
 504                                                   GucAction action, bool changeVal, int elevel);
 505 static void setup_scan_method_enforcement(ScanMethodHint *scanhint,
 506                                                                                   HintState *state);
 507 static int set_config_int32_option(const char *name, int32 value,
 508                                                                         GucContext context);
 509
 510 /* GUC variables */
 511 static bool     pg_hint_plan_enable_hint = true;
 512 static int debug_level = 0;
 513 static int      pg_hint_plan_parse_message_level = INFO;
 514 static int      pg_hint_plan_debug_message_level = LOG;
 515 /* Default is off, to keep backward compatibility. */
 516 static bool     pg_hint_plan_enable_hint_table = false;
 517
 518 static int plpgsql_recurse_level = 0;           /* PLpgSQL recursion level            */
 519 static int recurse_level = 0;           /* recursion level incl. direct SPI calls */
 520 static int hint_inhibit_level = 0;                      /* Inhibit hinting if this is above 0 */
 521                                                                                         /* (This could not be above 1)        */
 522 static int max_hint_nworkers = -1;              /* Maximum nworkers of Workers hints */
 523
 524 static const struct config_enum_entry parse_messages_level_options[] = {
 525         {"debug", DEBUG2, true},
 526         {"debug5", DEBUG5, false},
 527         {"debug4", DEBUG4, false},
 528         {"debug3", DEBUG3, false},
 529         {"debug2", DEBUG2, false},
 530         {"debug1", DEBUG1, false},
 531         {"log", LOG, false},
 532         {"info", INFO, false},
 533         {"notice", NOTICE, false},
 534         {"warning", WARNING, false},
 535         {"error", ERROR, false},
 536         /*
 537          * {"fatal", FATAL, true},
 538          * {"panic", PANIC, true},
 539          */
 540         {NULL, 0, false}
 541 };
 542
 543 static const struct config_enum_entry parse_debug_level_options[] = {
 544         {"off", 0, false},
 545         {"on", 1, false},
 546         {"detailed", 2, false},
 547         {"verbose", 3, false},
 548         {"0", 0, true},
 549         {"1", 1, true},
 550         {"2", 2, true},
 551         {"3", 3, true},
 552         {"no", 0, true},
 553         {"yes", 1, true},
 554         {"false", 0, true},
 555         {"true", 1, true},
 556         {NULL, 0, false}
 557 };
 558
 559 /* Saved hook values in case of unload */
 560 static post_parse_analyze_hook_type prev_post_parse_analyze_hook = NULL;
 561 static planner_hook_type prev_planner = NULL;
 562 static join_search_hook_type prev_join_search = NULL;
 563 static set_rel_pathlist_hook_type prev_set_rel_pathlist = NULL;
 564 static ProcessUtility_hook_type prev_ProcessUtility_hook = NULL;
 565
 566 /* Hold reference to currently active hint */
 567 static HintState *current_hint_state = NULL;
 568
 569 /*
 570  * List of hint contexts.  We treat the head of the list as the Top of the
 571  * context stack, so current_hint_state always points the first element of this
 572  * list.
 573  */
 574 static List *HintStateStack = NIL;
 575
 576 static const HintParser parsers[] = {
 577         {HINT_SEQSCAN, ScanMethodHintCreate, HINT_KEYWORD_SEQSCAN},
 578         {HINT_INDEXSCAN, ScanMethodHintCreate, HINT_KEYWORD_INDEXSCAN},
 579         {HINT_INDEXSCANREGEXP, ScanMethodHintCreate, HINT_KEYWORD_INDEXSCANREGEXP},
 580         {HINT_BITMAPSCAN, ScanMethodHintCreate, HINT_KEYWORD_BITMAPSCAN},
 581         {HINT_BITMAPSCANREGEXP, ScanMethodHintCreate,
 582          HINT_KEYWORD_BITMAPSCANREGEXP},
 583         {HINT_TIDSCAN, ScanMethodHintCreate, HINT_KEYWORD_TIDSCAN},
 584         {HINT_NOSEQSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOSEQSCAN},
 585         {HINT_NOINDEXSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOINDEXSCAN},
 586         {HINT_NOBITMAPSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOBITMAPSCAN},
 587         {HINT_NOTIDSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOTIDSCAN},
 588         {HINT_INDEXONLYSCAN, ScanMethodHintCreate, HINT_KEYWORD_INDEXONLYSCAN},
 589         {HINT_INDEXONLYSCANREGEXP, ScanMethodHintCreate,
 590          HINT_KEYWORD_INDEXONLYSCANREGEXP},
 591         {HINT_NOINDEXONLYSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOINDEXONLYSCAN},
 592
 593         {HINT_NESTLOOP, JoinMethodHintCreate, HINT_KEYWORD_NESTLOOP},
 594         {HINT_MERGEJOIN, JoinMethodHintCreate, HINT_KEYWORD_MERGEJOIN},
 595         {HINT_HASHJOIN, JoinMethodHintCreate, HINT_KEYWORD_HASHJOIN},
 596         {HINT_NONESTLOOP, JoinMethodHintCreate, HINT_KEYWORD_NONESTLOOP},
 597         {HINT_NOMERGEJOIN, JoinMethodHintCreate, HINT_KEYWORD_NOMERGEJOIN},
 598         {HINT_NOHASHJOIN, JoinMethodHintCreate, HINT_KEYWORD_NOHASHJOIN},
 599
 600         {HINT_LEADING, LeadingHintCreate, HINT_KEYWORD_LEADING},
 601         {HINT_SET, SetHintCreate, HINT_KEYWORD_SET},
 602         {HINT_ROWS, RowsHintCreate, HINT_KEYWORD_ROWS},
 603         {HINT_PARALLEL, ParallelHintCreate, HINT_KEYWORD_PARALLEL},
 604
 605         {NULL, NULL, HINT_KEYWORD_UNRECOGNIZED}
 606 };
 607
 608 PLpgSQL_plugin  plugin_funcs = {
 609         NULL,
 610         NULL,
 611         NULL,
 612         pg_hint_plan_plpgsql_stmt_beg,
 613         pg_hint_plan_plpgsql_stmt_end,
 614         NULL,
 615         NULL,
 616 };
 617
 618 /*
 619  * Module load callbacks
 620  */
 621 void
 622 _PG_init(void)
 623 {
 624         PLpgSQL_plugin  **var_ptr;
 625
 626         /* Define custom GUC variables. */
 627         DefineCustomBoolVariable("pg_hint_plan.enable_hint",
 628                          "Force planner to use plans specified in the hint comment preceding to the query.",
 629                                                          NULL,
 630                                                          &pg_hint_plan_enable_hint,
 631                                                          true,
 632                                                      PGC_USERSET,
 633                                                          0,
 634                                                          NULL,
 635                                                          NULL,
 636                                                          NULL);
 637
 638         DefineCustomEnumVariable("pg_hint_plan.debug_print",
 639                                                          "Logs results of hint parsing.",
 640                                                          NULL,
 641                                                          &debug_level,
 642                                                          false,
 643                                                          parse_debug_level_options,
 644                                                          PGC_USERSET,
 645                                                          0,
 646                                                          NULL,
 647                                                          NULL,
 648                                                          NULL);
 649
 650         DefineCustomEnumVariable("pg_hint_plan.parse_messages",
 651                                                          "Message level of parse errors.",
 652                                                          NULL,
 653                                                          &pg_hint_plan_parse_message_level,
 654                                                          INFO,
 655                                                          parse_messages_level_options,
 656                                                          PGC_USERSET,
 657                                                          0,
 658                                                          NULL,
 659                                                          NULL,
 660                                                          NULL);
 661
 662         DefineCustomEnumVariable("pg_hint_plan.message_level",
 663                                                          "Message level of debug messages.",
 664                                                          NULL,
 665                                                          &pg_hint_plan_debug_message_level,
 666                                                          LOG,
 667                                                          parse_messages_level_options,
 668                                                          PGC_USERSET,
 669                                                          0,
 670                                                          NULL,
 671                                                          NULL,
 672                                                          NULL);
 673
 674         DefineCustomBoolVariable("pg_hint_plan.enable_hint_table",
 675                                                          "Let pg_hint_plan look up the hint table.",
 676                                                          NULL,
 677                                                          &pg_hint_plan_enable_hint_table,
 678                                                          false,
 679                                                          PGC_USERSET,
 680                                                          0,
 681                                                          NULL,
 682                                                          NULL,
 683                                                          NULL);
 684
 685         /* Install hooks. */
 686         prev_post_parse_analyze_hook = post_parse_analyze_hook;
 687         post_parse_analyze_hook = pg_hint_plan_post_parse_analyze;
 688         prev_planner = planner_hook;
 689         planner_hook = pg_hint_plan_planner;
 690         prev_join_search = join_search_hook;
 691         join_search_hook = pg_hint_plan_join_search;
 692         prev_set_rel_pathlist = set_rel_pathlist_hook;
 693         set_rel_pathlist_hook = pg_hint_plan_set_rel_pathlist;
 694         prev_ProcessUtility_hook = ProcessUtility_hook;
 695         ProcessUtility_hook = pg_hint_plan_ProcessUtility;
 696
 697         /* setup PL/pgSQL plugin hook */
 698         var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
 699         *var_ptr = &plugin_funcs;
 700
 701         RegisterResourceReleaseCallback(plpgsql_query_erase_callback, NULL);
 702 }
 703
 704 /*
 705  * Module unload callback
 706  * XXX never called
 707  */
 708 void
 709 _PG_fini(void)
 710 {
 711         PLpgSQL_plugin  **var_ptr;
 712
 713         /* Uninstall hooks. */
 714         post_parse_analyze_hook = prev_post_parse_analyze_hook;
 715         planner_hook = prev_planner;
 716         join_search_hook = prev_join_search;
 717         set_rel_pathlist_hook = prev_set_rel_pathlist;
 718         ProcessUtility_hook = prev_ProcessUtility_hook;
 719
 720         /* uninstall PL/pgSQL plugin hook */
 721         var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
 722         *var_ptr = NULL;
 723 }
 724
 725 /*
 726  * create and delete functions the hint object
 727  */
 728
 729 static Hint *
 730 ScanMethodHintCreate(const char *hint_str, const char *keyword,
 731                                          HintKeyword hint_keyword)
 732 {
 733         ScanMethodHint *hint;
 734
 735         hint = palloc(sizeof(ScanMethodHint));
 736         hint->base.hint_str = hint_str;
 737         hint->base.keyword = keyword;
 738         hint->base.hint_keyword = hint_keyword;
 739         hint->base.type = HINT_TYPE_SCAN_METHOD;
 740         hint->base.state = HINT_STATE_NOTUSED;
 741         hint->base.delete_func = (HintDeleteFunction) ScanMethodHintDelete;
 742         hint->base.desc_func = (HintDescFunction) ScanMethodHintDesc;
 743         hint->base.cmp_func = (HintCmpFunction) ScanMethodHintCmp;
 744         hint->base.parse_func = (HintParseFunction) ScanMethodHintParse;
 745         hint->relname = NULL;
 746         hint->indexnames = NIL;
 747         hint->regexp = false;
 748         hint->enforce_mask = 0;
 749
 750         return (Hint *) hint;
 751 }
 752
 753 static void
 754 ScanMethodHintDelete(ScanMethodHint *hint)
 755 {
 756         if (!hint)
 757                 return;
 758
 759         if (hint->relname)
 760                 pfree(hint->relname);
 761         list_free_deep(hint->indexnames);
 762         pfree(hint);
 763 }
 764
 765 static Hint *
 766 JoinMethodHintCreate(const char *hint_str, const char *keyword,
 767                                          HintKeyword hint_keyword)
 768 {
 769         JoinMethodHint *hint;
 770
 771         hint = palloc(sizeof(JoinMethodHint));
 772         hint->base.hint_str = hint_str;
 773         hint->base.keyword = keyword;
 774         hint->base.hint_keyword = hint_keyword;
 775         hint->base.type = HINT_TYPE_JOIN_METHOD;
 776         hint->base.state = HINT_STATE_NOTUSED;
 777         hint->base.delete_func = (HintDeleteFunction) JoinMethodHintDelete;
 778         hint->base.desc_func = (HintDescFunction) JoinMethodHintDesc;
 779         hint->base.cmp_func = (HintCmpFunction) JoinMethodHintCmp;
 780         hint->base.parse_func = (HintParseFunction) JoinMethodHintParse;
 781         hint->nrels = 0;
 782         hint->inner_nrels = 0;
 783         hint->relnames = NULL;
 784         hint->enforce_mask = 0;
 785         hint->joinrelids = NULL;
 786         hint->inner_joinrelids = NULL;
 787
 788         return (Hint *) hint;
 789 }
 790
 791 static void
 792 JoinMethodHintDelete(JoinMethodHint *hint)
 793 {
 794         if (!hint)
 795                 return;
 796
 797         if (hint->relnames)
 798         {
 799                 int     i;
 800
 801                 for (i = 0; i < hint->nrels; i++)
 802                         pfree(hint->relnames[i]);
 803                 pfree(hint->relnames);
 804         }
 805
 806         bms_free(hint->joinrelids);
 807         bms_free(hint->inner_joinrelids);
 808         pfree(hint);
 809 }
 810
 811 static Hint *
 812 LeadingHintCreate(const char *hint_str, const char *keyword,
 813                                   HintKeyword hint_keyword)
 814 {
 815         LeadingHint        *hint;
 816
 817         hint = palloc(sizeof(LeadingHint));
 818         hint->base.hint_str = hint_str;
 819         hint->base.keyword = keyword;
 820         hint->base.hint_keyword = hint_keyword;
 821         hint->base.type = HINT_TYPE_LEADING;
 822         hint->base.state = HINT_STATE_NOTUSED;
 823         hint->base.delete_func = (HintDeleteFunction)LeadingHintDelete;
 824         hint->base.desc_func = (HintDescFunction) LeadingHintDesc;
 825         hint->base.cmp_func = (HintCmpFunction) LeadingHintCmp;
 826         hint->base.parse_func = (HintParseFunction) LeadingHintParse;
 827         hint->relations = NIL;
 828         hint->outer_inner = NULL;
 829
 830         return (Hint *) hint;
 831 }
 832
 833 static void
 834 LeadingHintDelete(LeadingHint *hint)
 835 {
 836         if (!hint)
 837                 return;
 838
 839         list_free_deep(hint->relations);
 840         if (hint->outer_inner)
 841                 pfree(hint->outer_inner);
 842         pfree(hint);
 843 }
 844
 845 static Hint *
 846 SetHintCreate(const char *hint_str, const char *keyword,
 847                           HintKeyword hint_keyword)
 848 {
 849         SetHint    *hint;
 850
 851         hint = palloc(sizeof(SetHint));
 852         hint->base.hint_str = hint_str;
 853         hint->base.keyword = keyword;
 854         hint->base.hint_keyword = hint_keyword;
 855         hint->base.type = HINT_TYPE_SET;
 856         hint->base.state = HINT_STATE_NOTUSED;
 857         hint->base.delete_func = (HintDeleteFunction) SetHintDelete;
 858         hint->base.desc_func = (HintDescFunction) SetHintDesc;
 859         hint->base.cmp_func = (HintCmpFunction) SetHintCmp;
 860         hint->base.parse_func = (HintParseFunction) SetHintParse;
 861         hint->name = NULL;
 862         hint->value = NULL;
 863         hint->words = NIL;
 864
 865         return (Hint *) hint;
 866 }
 867
 868 static void
 869 SetHintDelete(SetHint *hint)
 870 {
 871         if (!hint)
 872                 return;
 873
 874         if (hint->name)
 875                 pfree(hint->name);
 876         if (hint->value)
 877                 pfree(hint->value);
 878         if (hint->words)
 879                 list_free(hint->words);
 880         pfree(hint);
 881 }
 882
 883 static Hint *
 884 RowsHintCreate(const char *hint_str, const char *keyword,
 885                            HintKeyword hint_keyword)
 886 {
 887         RowsHint *hint;
 888
 889         hint = palloc(sizeof(RowsHint));
 890         hint->base.hint_str = hint_str;
 891         hint->base.keyword = keyword;
 892         hint->base.hint_keyword = hint_keyword;
 893         hint->base.type = HINT_TYPE_ROWS;
 894         hint->base.state = HINT_STATE_NOTUSED;
 895         hint->base.delete_func = (HintDeleteFunction) RowsHintDelete;
 896         hint->base.desc_func = (HintDescFunction) RowsHintDesc;
 897         hint->base.cmp_func = (HintCmpFunction) RowsHintCmp;
 898         hint->base.parse_func = (HintParseFunction) RowsHintParse;
 899         hint->nrels = 0;
 900         hint->inner_nrels = 0;
 901         hint->relnames = NULL;
 902         hint->joinrelids = NULL;
 903         hint->inner_joinrelids = NULL;
 904         hint->rows_str = NULL;
 905         hint->value_type = RVT_ABSOLUTE;
 906         hint->rows = 0;
 907
 908         return (Hint *) hint;
 909 }
 910
 911 static void
 912 RowsHintDelete(RowsHint *hint)
 913 {
 914         if (!hint)
 915                 return;
 916
 917         if (hint->relnames)
 918         {
 919                 int     i;
 920
 921                 for (i = 0; i < hint->nrels; i++)
 922                         pfree(hint->relnames[i]);
 923                 pfree(hint->relnames);
 924         }
 925
 926         bms_free(hint->joinrelids);
 927         bms_free(hint->inner_joinrelids);
 928         pfree(hint);
 929 }
 930
 931 static Hint *
 932 ParallelHintCreate(const char *hint_str, const char *keyword,
 933                                   HintKeyword hint_keyword)
 934 {
 935         ParallelHint *hint;
 936
 937         hint = palloc(sizeof(ParallelHint));
 938         hint->base.hint_str = hint_str;
 939         hint->base.keyword = keyword;
 940         hint->base.hint_keyword = hint_keyword;
 941         hint->base.type = HINT_TYPE_PARALLEL;
 942         hint->base.state = HINT_STATE_NOTUSED;
 943         hint->base.delete_func = (HintDeleteFunction) ParallelHintDelete;
 944         hint->base.desc_func = (HintDescFunction) ParallelHintDesc;
 945         hint->base.cmp_func = (HintCmpFunction) ParallelHintCmp;
 946         hint->base.parse_func = (HintParseFunction) ParallelHintParse;
 947         hint->relname = NULL;
 948         hint->nworkers = 0;
 949         hint->nworkers_str = "0";
 950
 951         return (Hint *) hint;
 952 }
 953
 954 static void
 955 ParallelHintDelete(ParallelHint *hint)
 956 {
 957         if (!hint)
 958                 return;
 959
 960         if (hint->relname)
 961                 pfree(hint->relname);
 962         pfree(hint);
 963 }
 964
 965
 966 static HintState *
 967 HintStateCreate(void)
 968 {
 969         HintState   *hstate;
 970
 971         hstate = palloc(sizeof(HintState));
 972         hstate->hint_str = NULL;
 973         hstate->nall_hints = 0;
 974         hstate->max_all_hints = 0;
 975         hstate->all_hints = NULL;
 976         memset(hstate->num_hints, 0, sizeof(hstate->num_hints));
 977         hstate->scan_hints = NULL;
 978         hstate->init_scan_mask = 0;
 979         hstate->init_nworkers = 0;
 980         hstate->init_min_para_tablescan_size = 0;
 981         hstate->init_min_para_indexscan_size = 0;
 982         hstate->init_paratup_cost = 0;
 983         hstate->init_parasetup_cost = 0;
 984         hstate->current_root = NULL;
 985         hstate->parent_relid = 0;
 986         hstate->parent_scan_hint = NULL;
 987         hstate->parent_parallel_hint = NULL;
 988         hstate->parent_index_infos = NIL;
 989         hstate->join_hints = NULL;
 990         hstate->init_join_mask = 0;
 991         hstate->join_hint_level = NULL;
 992         hstate->leading_hint = NULL;
 993         hstate->context = superuser() ? PGC_SUSET : PGC_USERSET;
 994         hstate->set_hints = NULL;
 995         hstate->rows_hints = NULL;
 996         hstate->parallel_hints = NULL;
 997
 998         return hstate;
 999 }
1000
1001 static void
1002 HintStateDelete(HintState *hstate)
1003 {
1004         int                     i;
1005
1006         if (!hstate)
1007                 return;
1008
1009         if (hstate->hint_str)
1010                 pfree(hstate->hint_str);
1011
1012         for (i = 0; i < hstate->num_hints[HINT_TYPE_SCAN_METHOD]; i++)
1013                 hstate->all_hints[i]->delete_func(hstate->all_hints[i]);
1014         if (hstate->all_hints)
1015                 pfree(hstate->all_hints);
1016         if (hstate->parent_index_infos)
1017                 list_free(hstate->parent_index_infos);
1018 }
1019
1020 /*
1021  * Copy given value into buf, with quoting with '"' if necessary.
1022  */
1023 static void
1024 quote_value(StringInfo buf, const char *value)
1025 {
1026         bool            need_quote = false;
1027         const char *str;
1028
1029         for (str = value; *str != '\0'; str++)
1030         {
1031                 if (isspace(*str) || *str == '(' || *str == ')' || *str == '"')
1032                 {
1033                         need_quote = true;
1034                         appendStringInfoCharMacro(buf, '"');
1035                         break;
1036                 }
1037         }
1038
1039         for (str = value; *str != '\0'; str++)
1040         {
1041                 if (*str == '"')
1042                         appendStringInfoCharMacro(buf, '"');
1043
1044                 appendStringInfoCharMacro(buf, *str);
1045         }
1046
1047         if (need_quote)
1048                 appendStringInfoCharMacro(buf, '"');
1049 }
1050
1051 static void
1052 ScanMethodHintDesc(ScanMethodHint *hint, StringInfo buf, bool nolf)
1053 {
1054         ListCell   *l;
1055
1056         appendStringInfo(buf, "%s(", hint->base.keyword);
1057         if (hint->relname != NULL)
1058         {
1059                 quote_value(buf, hint->relname);
1060                 foreach(l, hint->indexnames)
1061                 {
1062                         appendStringInfoCharMacro(buf, ' ');
1063                         quote_value(buf, (char *) lfirst(l));
1064                 }
1065         }
1066         appendStringInfoString(buf, ")");
1067         if (!nolf)
1068                 appendStringInfoChar(buf, '\n');
1069 }
1070
1071 static void
1072 JoinMethodHintDesc(JoinMethodHint *hint, StringInfo buf, bool nolf)
1073 {
1074         int     i;
1075
1076         appendStringInfo(buf, "%s(", hint->base.keyword);
1077         if (hint->relnames != NULL)
1078         {
1079                 quote_value(buf, hint->relnames[0]);
1080                 for (i = 1; i < hint->nrels; i++)
1081                 {
1082                         appendStringInfoCharMacro(buf, ' ');
1083                         quote_value(buf, hint->relnames[i]);
1084                 }
1085         }
1086         appendStringInfoString(buf, ")");
1087         if (!nolf)
1088                 appendStringInfoChar(buf, '\n');
1089 }
1090
1091 static void
1092 OuterInnerDesc(OuterInnerRels *outer_inner, StringInfo buf)
1093 {
1094         if (outer_inner->relation == NULL)
1095         {
1096                 bool            is_first;
1097                 ListCell   *l;
1098
1099                 is_first = true;
1100
1101                 appendStringInfoCharMacro(buf, '(');
1102                 foreach(l, outer_inner->outer_inner_pair)
1103                 {
1104                         if (is_first)
1105                                 is_first = false;
1106                         else
1107                                 appendStringInfoCharMacro(buf, ' ');
1108
1109                         OuterInnerDesc(lfirst(l), buf);
1110                 }
1111
1112                 appendStringInfoCharMacro(buf, ')');
1113         }
1114         else
1115                 quote_value(buf, outer_inner->relation);
1116 }
1117
1118 static void
1119 LeadingHintDesc(LeadingHint *hint, StringInfo buf, bool nolf)
1120 {
1121         appendStringInfo(buf, "%s(", HINT_LEADING);
1122         if (hint->outer_inner == NULL)
1123         {
1124                 ListCell   *l;
1125                 bool            is_first;
1126
1127                 is_first = true;
1128
1129                 foreach(l, hint->relations)
1130                 {
1131                         if (is_first)
1132                                 is_first = false;
1133                         else
1134                                 appendStringInfoCharMacro(buf, ' ');
1135
1136                         quote_value(buf, (char *) lfirst(l));
1137                 }
1138         }
1139         else
1140                 OuterInnerDesc(hint->outer_inner, buf);
1141
1142         appendStringInfoString(buf, ")");
1143         if (!nolf)
1144                 appendStringInfoChar(buf, '\n');
1145 }
1146
1147 static void
1148 SetHintDesc(SetHint *hint, StringInfo buf, bool nolf)
1149 {
1150         bool            is_first = true;
1151         ListCell   *l;
1152
1153         appendStringInfo(buf, "%s(", HINT_SET);
1154         foreach(l, hint->words)
1155         {
1156                 if (is_first)
1157                         is_first = false;
1158                 else
1159                         appendStringInfoCharMacro(buf, ' ');
1160
1161                 quote_value(buf, (char *) lfirst(l));
1162         }
1163         appendStringInfo(buf, ")");
1164         if (!nolf)
1165                 appendStringInfoChar(buf, '\n');
1166 }
1167
1168 static void
1169 RowsHintDesc(RowsHint *hint, StringInfo buf, bool nolf)
1170 {
1171         int     i;
1172
1173         appendStringInfo(buf, "%s(", hint->base.keyword);
1174         if (hint->relnames != NULL)
1175         {
1176                 quote_value(buf, hint->relnames[0]);
1177                 for (i = 1; i < hint->nrels; i++)
1178                 {
1179                         appendStringInfoCharMacro(buf, ' ');
1180                         quote_value(buf, hint->relnames[i]);
1181                 }
1182         }
1183         appendStringInfo(buf, " %s", hint->rows_str);
1184         appendStringInfoString(buf, ")");
1185         if (!nolf)
1186                 appendStringInfoChar(buf, '\n');
1187 }
1188
1189 static void
1190 ParallelHintDesc(ParallelHint *hint, StringInfo buf, bool nolf)
1191 {
1192         appendStringInfo(buf, "%s(", hint->base.keyword);
1193         if (hint->relname != NULL)
1194         {
1195                 quote_value(buf, hint->relname);
1196
1197                 /* number of workers  */
1198                 appendStringInfoCharMacro(buf, ' ');
1199                 quote_value(buf, hint->nworkers_str);
1200                 /* application mode of num of workers */
1201                 appendStringInfoCharMacro(buf, ' ');
1202                 appendStringInfoString(buf,
1203                                                            (hint->force_parallel ? "hard" : "soft"));
1204         }
1205         appendStringInfoString(buf, ")");
1206         if (!nolf)
1207                 appendStringInfoChar(buf, '\n');
1208 }
1209
1210 /*
1211  * Append string which represents all hints in a given state to buf, with
1212  * preceding title with them.
1213  */
1214 static void
1215 desc_hint_in_state(HintState *hstate, StringInfo buf, const char *title,
1216                                    HintStatus state, bool nolf)
1217 {
1218         int     i, nshown;
1219
1220         appendStringInfo(buf, "%s:", title);
1221         if (!nolf)
1222                 appendStringInfoChar(buf, '\n');
1223
1224         nshown = 0;
1225         for (i = 0; i < hstate->nall_hints; i++)
1226         {
1227                 if (hstate->all_hints[i]->state != state)
1228                         continue;
1229
1230                 hstate->all_hints[i]->desc_func(hstate->all_hints[i], buf, nolf);
1231                 nshown++;
1232         }
1233
1234         if (nolf && nshown == 0)
1235                 appendStringInfoString(buf, "(none)");
1236 }
1237
1238 /*
1239  * Dump contents of given hstate to server log with log level LOG.
1240  */
1241 static void
1242 HintStateDump(HintState *hstate)
1243 {
1244         StringInfoData  buf;
1245
1246         if (!hstate)
1247         {
1248                 elog(pg_hint_plan_debug_message_level, "pg_hint_plan:\nno hint");
1249                 return;
1250         }
1251
1252         initStringInfo(&buf);
1253
1254         appendStringInfoString(&buf, "pg_hint_plan:\n");
1255         desc_hint_in_state(hstate, &buf, "used hint", HINT_STATE_USED, false);
1256         desc_hint_in_state(hstate, &buf, "not used hint", HINT_STATE_NOTUSED, false);
1257         desc_hint_in_state(hstate, &buf, "duplication hint", HINT_STATE_DUPLICATION, false);
1258         desc_hint_in_state(hstate, &buf, "error hint", HINT_STATE_ERROR, false);
1259
1260         ereport(pg_hint_plan_debug_message_level,
1261                         (errmsg ("%s", buf.data)));
1262
1263         pfree(buf.data);
1264 }
1265
1266 static void
1267 HintStateDump2(HintState *hstate)
1268 {
1269         StringInfoData  buf;
1270
1271         if (!hstate)
1272         {
1273                 elog(pg_hint_plan_debug_message_level,
1274                          "pg_hint_plan%s: HintStateDump: no hint", qnostr);
1275                 return;
1276         }
1277
1278         initStringInfo(&buf);
1279         appendStringInfo(&buf, "pg_hint_plan%s: HintStateDump: ", qnostr);
1280         desc_hint_in_state(hstate, &buf, "{used hints", HINT_STATE_USED, true);
1281         desc_hint_in_state(hstate, &buf, "}, {not used hints", HINT_STATE_NOTUSED, true);
1282         desc_hint_in_state(hstate, &buf, "}, {duplicate hints", HINT_STATE_DUPLICATION, true);
1283         desc_hint_in_state(hstate, &buf, "}, {error hints", HINT_STATE_ERROR, true);
1284         appendStringInfoChar(&buf, '}');
1285
1286         ereport(pg_hint_plan_debug_message_level,
1287                         (errmsg("%s", buf.data),
1288                          errhidestmt(true),
1289                          errhidecontext(true)));
1290
1291         pfree(buf.data);
1292 }
1293
1294 /*
1295  * compare functions
1296  */
1297
1298 static int
1299 RelnameCmp(const void *a, const void *b)
1300 {
1301         const char *relnamea = *((const char **) a);
1302         const char *relnameb = *((const char **) b);
1303
1304         return strcmp(relnamea, relnameb);
1305 }
1306
1307 static int
1308 ScanMethodHintCmp(const ScanMethodHint *a, const ScanMethodHint *b)
1309 {
1310         return RelnameCmp(&a->relname, &b->relname);
1311 }
1312
1313 static int
1314 JoinMethodHintCmp(const JoinMethodHint *a, const JoinMethodHint *b)
1315 {
1316         int     i;
1317
1318         if (a->nrels != b->nrels)
1319                 return a->nrels - b->nrels;
1320
1321         for (i = 0; i < a->nrels; i++)
1322         {
1323                 int     result;
1324                 if ((result = RelnameCmp(&a->relnames[i], &b->relnames[i])) != 0)
1325                         return result;
1326         }
1327
1328         return 0;
1329 }
1330
1331 static int
1332 LeadingHintCmp(const LeadingHint *a, const LeadingHint *b)
1333 {
1334         return 0;
1335 }
1336
1337 static int
1338 SetHintCmp(const SetHint *a, const SetHint *b)
1339 {
1340         return strcmp(a->name, b->name);
1341 }
1342
1343 static int
1344 RowsHintCmp(const RowsHint *a, const RowsHint *b)
1345 {
1346         int     i;
1347
1348         if (a->nrels != b->nrels)
1349                 return a->nrels - b->nrels;
1350
1351         for (i = 0; i < a->nrels; i++)
1352         {
1353                 int     result;
1354                 if ((result = RelnameCmp(&a->relnames[i], &b->relnames[i])) != 0)
1355                         return result;
1356         }
1357
1358         return 0;
1359 }
1360
1361 static int
1362 ParallelHintCmp(const ParallelHint *a, const ParallelHint *b)
1363 {
1364         return RelnameCmp(&a->relname, &b->relname);
1365 }
1366
1367 static int
1368 HintCmp(const void *a, const void *b)
1369 {
1370         const Hint *hinta = *((const Hint **) a);
1371         const Hint *hintb = *((const Hint **) b);
1372
1373         if (hinta->type != hintb->type)
1374                 return hinta->type - hintb->type;
1375         if (hinta->state == HINT_STATE_ERROR)
1376                 return -1;
1377         if (hintb->state == HINT_STATE_ERROR)
1378                 return 1;
1379         return hinta->cmp_func(hinta, hintb);
1380 }
1381
1382 /*
1383  * Returns byte offset of hint b from hint a.  If hint a was specified before
1384  * b, positive value is returned.
1385  */
1386 static int
1387 HintCmpWithPos(const void *a, const void *b)
1388 {
1389         const Hint *hinta = *((const Hint **) a);
1390         const Hint *hintb = *((const Hint **) b);
1391         int             result;
1392
1393         result = HintCmp(a, b);
1394         if (result == 0)
1395                 result = hinta->hint_str - hintb->hint_str;
1396
1397         return result;
1398 }
1399
1400 /*
1401  * parse functions
1402  */
1403 static const char *
1404 parse_keyword(const char *str, StringInfo buf)
1405 {
1406         skip_space(str);
1407
1408         while (!isspace(*str) && *str != '(' && *str != '\0')
1409                 appendStringInfoCharMacro(buf, *str++);
1410
1411         return str;
1412 }
1413
1414 static const char *
1415 skip_parenthesis(const char *str, char parenthesis)
1416 {
1417         skip_space(str);
1418
1419         if (*str != parenthesis)
1420         {
1421                 if (parenthesis == '(')
1422                         hint_ereport(str, ("Opening parenthesis is necessary."));
1423                 else if (parenthesis == ')')
1424                         hint_ereport(str, ("Closing parenthesis is necessary."));
1425
1426                 return NULL;
1427         }
1428
1429         str++;
1430
1431         return str;
1432 }
1433
1434 /*
1435  * Parse a token from str, and store malloc'd copy into word.  A token can be
1436  * quoted with '"'.  Return value is pointer to unparsed portion of original
1437  * string, or NULL if an error occurred.
1438  *
1439  * Parsed token is truncated within NAMEDATALEN-1 bytes, when truncate is true.
1440  */
1441 static const char *
1442 parse_quoted_value(const char *str, char **word, bool truncate)
1443 {
1444         StringInfoData  buf;
1445         bool                    in_quote;
1446
1447         /* Skip leading spaces. */
1448         skip_space(str);
1449
1450         initStringInfo(&buf);
1451         if (*str == '"')
1452         {
1453                 str++;
1454                 in_quote = true;
1455         }
1456         else
1457                 in_quote = false;
1458
1459         while (true)
1460         {
1461                 if (in_quote)
1462                 {
1463                         /* Double quotation must be closed. */
1464                         if (*str == '\0')
1465                         {
1466                                 pfree(buf.data);
1467                                 hint_ereport(str, ("Unterminated quoted string."));
1468                                 return NULL;
1469                         }
1470
1471                         /*
1472                          * Skip escaped double quotation.
1473                          *
1474                          * We don't allow slash-asterisk and asterisk-slash (delimiters of
1475                          * block comments) to be an object name, so users must specify
1476                          * alias for such object names.
1477                          *
1478                          * Those special names can be allowed if we care escaped slashes
1479                          * and asterisks, but we don't.
1480                          */
1481                         if (*str == '"')
1482                         {
1483                                 str++;
1484                                 if (*str != '"')
1485                                         break;
1486                         }
1487                 }
1488                 else if (isspace(*str) || *str == '(' || *str == ')' || *str == '"' ||
1489                                  *str == '\0')
1490                         break;
1491
1492                 appendStringInfoCharMacro(&buf, *str++);
1493         }
1494
1495         if (buf.len == 0)
1496         {
1497                 hint_ereport(str, ("Zero-length delimited string."));
1498
1499                 pfree(buf.data);
1500
1501                 return NULL;
1502         }
1503
1504         /* Truncate name if it's too long */
1505         if (truncate)
1506                 truncate_identifier(buf.data, strlen(buf.data), true);
1507
1508         *word = buf.data;
1509
1510         return str;
1511 }
1512
1513 static OuterInnerRels *
1514 OuterInnerRelsCreate(char *name, List *outer_inner_list)
1515 {
1516         OuterInnerRels *outer_inner;
1517
1518         outer_inner = palloc(sizeof(OuterInnerRels));
1519         outer_inner->relation = name;
1520         outer_inner->outer_inner_pair = outer_inner_list;
1521
1522         return outer_inner;
1523 }
1524
1525 static const char *
1526 parse_parentheses_Leading_in(const char *str, OuterInnerRels **outer_inner)
1527 {
1528         List   *outer_inner_pair = NIL;
1529
1530         if ((str = skip_parenthesis(str, '(')) == NULL)
1531                 return NULL;
1532
1533         skip_space(str);
1534
1535         /* Store words in parentheses into outer_inner_list. */
1536         while(*str != ')' && *str != '\0')
1537         {
1538                 OuterInnerRels *outer_inner_rels;
1539
1540                 if (*str == '(')
1541                 {
1542                         str = parse_parentheses_Leading_in(str, &outer_inner_rels);
1543                         if (str == NULL)
1544                                 break;
1545                 }
1546                 else
1547                 {
1548                         char   *name;
1549
1550                         if ((str = parse_quoted_value(str, &name, true)) == NULL)
1551                                 break;
1552                         else
1553                                 outer_inner_rels = OuterInnerRelsCreate(name, NIL);
1554                 }
1555
1556                 outer_inner_pair = lappend(outer_inner_pair, outer_inner_rels);
1557                 skip_space(str);
1558         }
1559
1560         if (str == NULL ||
1561                 (str = skip_parenthesis(str, ')')) == NULL)
1562         {
1563                 list_free(outer_inner_pair);
1564                 return NULL;
1565         }
1566
1567         *outer_inner = OuterInnerRelsCreate(NULL, outer_inner_pair);
1568
1569         return str;
1570 }
1571
1572 static const char *
1573 parse_parentheses_Leading(const char *str, List **name_list,
1574         OuterInnerRels **outer_inner)
1575 {
1576         char   *name;
1577         bool    truncate = true;
1578
1579         if ((str = skip_parenthesis(str, '(')) == NULL)
1580                 return NULL;
1581
1582         skip_space(str);
1583         if (*str =='(')
1584         {
1585                 if ((str = parse_parentheses_Leading_in(str, outer_inner)) == NULL)
1586                         return NULL;
1587         }
1588         else
1589         {
1590                 /* Store words in parentheses into name_list. */
1591                 while(*str != ')' && *str != '\0')
1592                 {
1593                         if ((str = parse_quoted_value(str, &name, truncate)) == NULL)
1594                         {
1595                                 list_free(*name_list);
1596                                 return NULL;
1597                         }
1598
1599                         *name_list = lappend(*name_list, name);
1600                         skip_space(str);
1601                 }
1602         }
1603
1604         if ((str = skip_parenthesis(str, ')')) == NULL)
1605                 return NULL;
1606         return str;
1607 }
1608
1609 static const char *
1610 parse_parentheses(const char *str, List **name_list, HintKeyword keyword)
1611 {
1612         char   *name;
1613         bool    truncate = true;
1614
1615         if ((str = skip_parenthesis(str, '(')) == NULL)
1616                 return NULL;
1617
1618         skip_space(str);
1619
1620         /* Store words in parentheses into name_list. */
1621         while(*str != ')' && *str != '\0')
1622         {
1623                 if ((str = parse_quoted_value(str, &name, truncate)) == NULL)
1624                 {
1625                         list_free(*name_list);
1626                         return NULL;
1627                 }
1628
1629                 *name_list = lappend(*name_list, name);
1630                 skip_space(str);
1631
1632                 if (keyword == HINT_KEYWORD_INDEXSCANREGEXP ||
1633                         keyword == HINT_KEYWORD_INDEXONLYSCANREGEXP ||
1634                         keyword == HINT_KEYWORD_BITMAPSCANREGEXP ||
1635                         keyword == HINT_KEYWORD_SET)
1636                 {
1637                         truncate = false;
1638                 }
1639         }
1640
1641         if ((str = skip_parenthesis(str, ')')) == NULL)
1642                 return NULL;
1643         return str;
1644 }
1645
1646 static void
1647 parse_hints(HintState *hstate, Query *parse, const char *str)
1648 {
1649         StringInfoData  buf;
1650         char               *head;
1651
1652         initStringInfo(&buf);
1653         while (*str != '\0')
1654         {
1655                 const HintParser *parser;
1656
1657                 /* in error message, we output the comment including the keyword. */
1658                 head = (char *) str;
1659
1660                 /* parse only the keyword of the hint. */
1661                 resetStringInfo(&buf);
1662                 str = parse_keyword(str, &buf);
1663
1664                 for (parser = parsers; parser->keyword != NULL; parser++)
1665                 {
1666                         char   *keyword = parser->keyword;
1667                         Hint   *hint;
1668
1669                         if (pg_strcasecmp(buf.data, keyword) != 0)
1670                                 continue;
1671
1672                         hint = parser->create_func(head, keyword, parser->hint_keyword);
1673
1674                         /* parser of each hint does parse in a parenthesis. */
1675                         if ((str = hint->parse_func(hint, hstate, parse, str)) == NULL)
1676                         {
1677                                 hint->delete_func(hint);
1678                                 pfree(buf.data);
1679                                 return;
1680                         }
1681
1682                         /*
1683                          * Add hint information into all_hints array.  If we don't have
1684                          * enough space, double the array.
1685                          */
1686                         if (hstate->nall_hints == 0)
1687                         {
1688                                 hstate->max_all_hints = HINT_ARRAY_DEFAULT_INITSIZE;
1689                                 hstate->all_hints = (Hint **)
1690                                         palloc(sizeof(Hint *) * hstate->max_all_hints);
1691                         }
1692                         else if (hstate->nall_hints == hstate->max_all_hints)
1693                         {
1694                                 hstate->max_all_hints *= 2;
1695                                 hstate->all_hints = (Hint **)
1696                                         repalloc(hstate->all_hints,
1697                                                          sizeof(Hint *) * hstate->max_all_hints);
1698                         }
1699
1700                         hstate->all_hints[hstate->nall_hints] = hint;
1701                         hstate->nall_hints++;
1702
1703                         skip_space(str);
1704
1705                         break;
1706                 }
1707
1708                 if (parser->keyword == NULL)
1709                 {
1710                         hint_ereport(head,
1711                                                  ("Unrecognized hint keyword \"%s\".", buf.data));
1712                         pfree(buf.data);
1713                         return;
1714                 }
1715         }
1716
1717         pfree(buf.data);
1718 }
1719
1720
1721 /*
1722  * Get hints from table by client-supplied query string and application name.
1723  */
1724 static const char *
1725 get_hints_from_table(const char *client_query, const char *client_application)
1726 {
1727         const char *search_query =
1728                 "SELECT hints "
1729                 "  FROM hint_plan.hints "
1730                 " WHERE norm_query_string = $1 "
1731                 "   AND ( application_name = $2 "
1732                 "    OR application_name = '' ) "
1733                 " ORDER BY application_name DESC";
1734         static SPIPlanPtr plan = NULL;
1735         char   *hints = NULL;
1736         Oid             argtypes[2] = { TEXTOID, TEXTOID };
1737         Datum   values[2];
1738         char    nulls[2] = {' ', ' '};
1739         text   *qry;
1740         text   *app;
1741
1742         PG_TRY();
1743         {
1744                 bool snapshot_set = false;
1745
1746                 hint_inhibit_level++;
1747
1748                 if (!ActiveSnapshotSet())
1749                 {
1750                         PushActiveSnapshot(GetTransactionSnapshot());
1751                         snapshot_set = true;
1752                 }
1753
1754                 SPI_connect();
1755
1756                 if (plan == NULL)
1757                 {
1758                         SPIPlanPtr      p;
1759                         p = SPI_prepare(search_query, 2, argtypes);
1760                         plan = SPI_saveplan(p);
1761                         SPI_freeplan(p);
1762                 }
1763
1764                 qry = cstring_to_text(client_query);
1765                 app = cstring_to_text(client_application);
1766                 values[0] = PointerGetDatum(qry);
1767                 values[1] = PointerGetDatum(app);
1768
1769                 SPI_execute_plan(plan, values, nulls, true, 1);
1770
1771                 if (SPI_processed > 0)
1772                 {
1773                         char    *buf;
1774
1775                         hints = SPI_getvalue(SPI_tuptable->vals[0],
1776                                                                  SPI_tuptable->tupdesc, 1);
1777                         /*
1778                          * Here we use SPI_palloc to ensure that hints string is valid even
1779                          * after SPI_finish call.  We can't use simple palloc because it
1780                          * allocates memory in SPI's context and that context is deleted in
1781                          * SPI_finish.
1782                          */
1783                         buf = SPI_palloc(strlen(hints) + 1);
1784                         strcpy(buf, hints);
1785                         hints = buf;
1786                 }
1787
1788                 SPI_finish();
1789
1790                 if (snapshot_set)
1791                         PopActiveSnapshot();
1792
1793                 hint_inhibit_level--;
1794         }
1795         PG_CATCH();
1796         {
1797                 hint_inhibit_level--;
1798                 PG_RE_THROW();
1799         }
1800         PG_END_TRY();
1801
1802         return hints;
1803 }
1804
1805 /*
1806  * Get client-supplied query string. Addtion to that the jumbled query is
1807  * supplied if the caller requested. From the restriction of JumbleQuery, some
1808  * kind of query needs special amendments. Reutrns NULL if this query doesn't
1809  * change the current hint. This function returns NULL also when something
1810  * wrong has happend and let the caller continue using the current hints.
1811  */
1812 static const char *
1813 get_query_string(ParseState *pstate, Query *query, Query **jumblequery)
1814 {
1815         const char *p = debug_query_string;
1816
1817         /*
1818          * If debug_query_string is set, it is the top level statement. But in some
1819          * cases we reach here with debug_query_string set NULL for example in the
1820          * case of DESCRIBE message handling or EXECUTE command. We may still see a
1821          * candidate top-level query in pstate in the case.
1822          */
1823         if (pstate && pstate->p_sourcetext)
1824                 p = pstate->p_sourcetext;
1825
1826         /* We don't see a query string, return NULL */
1827         if (!p)
1828                 return NULL;
1829
1830         if (jumblequery != NULL)
1831                 *jumblequery = query;
1832
1833         if (query->commandType == CMD_UTILITY)
1834         {
1835                 Query *target_query = (Query *)query->utilityStmt;
1836
1837                 /*
1838                  * Some CMD_UTILITY statements have a subquery that we can hint on.
1839                  * Since EXPLAIN can be placed before other kind of utility statements
1840                  * and EXECUTE can be contained other kind of utility statements, these
1841                  * conditions are not mutually exclusive and should be considered in
1842                  * this order.
1843                  */
1844                 if (IsA(target_query, ExplainStmt))
1845                 {
1846                         ExplainStmt *stmt = (ExplainStmt *)target_query;
1847
1848                         Assert(IsA(stmt->query, Query));
1849                         target_query = (Query *)stmt->query;
1850
1851                         /* strip out the top-level query for further processing */
1852                         if (target_query->commandType == CMD_UTILITY &&
1853                                 target_query->utilityStmt != NULL)
1854                                 target_query = (Query *)target_query->utilityStmt;
1855                 }
1856
1857                 if (IsA(target_query, DeclareCursorStmt))
1858                 {
1859                         DeclareCursorStmt *stmt = (DeclareCursorStmt *)target_query;
1860                         Query *query = (Query *)stmt->query;
1861
1862                         /* the target must be CMD_SELECT in this case */
1863                         Assert(IsA(query, Query) && query->commandType == CMD_SELECT);
1864                         target_query = query;
1865                 }
1866
1867                 if (IsA(target_query, CreateTableAsStmt))
1868                 {
1869                         CreateTableAsStmt  *stmt = (CreateTableAsStmt *) target_query;
1870
1871                         Assert(IsA(stmt->query, Query));
1872                         target_query = (Query *) stmt->query;
1873
1874                         /* strip out the top-level query for further processing */
1875                         if (target_query->commandType == CMD_UTILITY &&
1876                                 target_query->utilityStmt != NULL)
1877                                 target_query = (Query *)target_query->utilityStmt;
1878                 }
1879
1880                 if (IsA(target_query, ExecuteStmt))
1881                 {
1882                         /*
1883                          * Use the prepared query for EXECUTE. The Query for jumble
1884                          * also replaced with the corresponding one.
1885                          */
1886                         ExecuteStmt *stmt = (ExecuteStmt *)target_query;
1887                         PreparedStatement  *entry;
1888
1889                         entry = FetchPreparedStatement(stmt->name, true);
1890
1891                         if (entry->plansource->is_valid)
1892                         {
1893                                 p = entry->plansource->query_string;
1894                                 target_query = (Query *) linitial (entry->plansource->query_list);
1895                         }
1896                         else
1897                         {
1898                                 /* igonre the hint for EXECUTE if invalidated */
1899                                 p = NULL;
1900                                 target_query = NULL;
1901                         }
1902                 }
1903
1904                 /* JumbleQuery accespts only a non-utility Query */
1905                 if (target_query &&
1906                         (!IsA(target_query, Query) ||
1907                          target_query->utilityStmt != NULL))
1908                         target_query = NULL;
1909
1910                 if (jumblequery)
1911                         *jumblequery = target_query;
1912         }
1913         /*
1914          * Return NULL if pstate is not of top-level query.  We don't need this
1915          * when jumble info is not requested or cannot do this when pstate is NULL.
1916          */
1917         else if (!jumblequery && pstate && pstate->p_sourcetext != p &&
1918                          strcmp(pstate->p_sourcetext, p) != 0)
1919                 p = NULL;
1920
1921         return p;
1922 }
1923
1924 /*
1925  * Get hints from the head block comment in client-supplied query string.
1926  */
1927 static const char *
1928 get_hints_from_comment(const char *p)
1929 {
1930         const char *hint_head;
1931         char       *head;
1932         char       *tail;
1933         int                     len;
1934
1935         if (p == NULL)
1936                 return NULL;
1937
1938         /* extract query head comment. */
1939         hint_head = strstr(p, HINT_START);
1940         if (hint_head == NULL)
1941                 return NULL;
1942         for (;p < hint_head; p++)
1943         {
1944                 /*
1945                  * Allow these characters precedes hint comment:
1946                  *   - digits
1947                  *   - alphabets which are in ASCII range
1948                  *   - space, tabs and new-lines
1949                  *   - underscores, for identifier
1950                  *   - commas, for SELECT clause, EXPLAIN and PREPARE
1951                  *   - parentheses, for EXPLAIN and PREPARE
1952                  *
1953                  * Note that we don't use isalpha() nor isalnum() in ctype.h here to
1954                  * avoid behavior which depends on locale setting.
1955                  */
1956                 if (!(*p >= '0' && *p <= '9') &&
1957                         !(*p >= 'A' && *p <= 'Z') &&
1958                         !(*p >= 'a' && *p <= 'z') &&
1959                         !isspace(*p) &&
1960                         *p != '_' &&
1961                         *p != ',' &&
1962                         *p != '(' && *p != ')')
1963                         return NULL;
1964         }
1965
1966         len = strlen(HINT_START);
1967         head = (char *) p;
1968         p += len;
1969         skip_space(p);
1970
1971         /* find hint end keyword. */
1972         if ((tail = strstr(p, HINT_END)) == NULL)
1973         {
1974                 hint_ereport(head, ("Unterminated block comment."));
1975                 return NULL;
1976         }
1977
1978         /* We don't support nested block comments. */
1979         if ((head = strstr(p, BLOCK_COMMENT_START)) != NULL && head < tail)
1980         {
1981                 hint_ereport(head, ("Nested block comments are not supported."));
1982                 return NULL;
1983         }
1984
1985         /* Make a copy of hint. */
1986         len = tail - p;
1987         head = palloc(len + 1);
1988         memcpy(head, p, len);
1989         head[len] = '\0';
1990         p = head;
1991
1992         return p;
1993 }
1994
1995 /*
1996  * Parse hints that got, create hint struct from parse tree and parse hints.
1997  */
1998 static HintState *
1999 create_hintstate(Query *parse, const char *hints)
2000 {
2001         const char *p;
2002         int                     i;
2003         HintState   *hstate;
2004
2005         if (hints == NULL)
2006                 return NULL;
2007
2008         /* -1 means that no Parallel hint is specified. */
2009         max_hint_nworkers = -1;
2010
2011         p = hints;
2012         hstate = HintStateCreate();
2013         hstate->hint_str = (char *) hints;
2014
2015         /* parse each hint. */
2016         parse_hints(hstate, parse, p);
2017
2018         /* When nothing specified a hint, we free HintState and returns NULL. */
2019         if (hstate->nall_hints == 0)
2020         {
2021                 HintStateDelete(hstate);
2022                 return NULL;
2023         }
2024
2025         /* Sort hints in order of original position. */
2026         qsort(hstate->all_hints, hstate->nall_hints, sizeof(Hint *),
2027                   HintCmpWithPos);
2028
2029         /* Count number of hints per hint-type. */
2030         for (i = 0; i < hstate->nall_hints; i++)
2031         {
2032                 Hint   *cur_hint = hstate->all_hints[i];
2033                 hstate->num_hints[cur_hint->type]++;
2034         }
2035
2036         /*
2037          * If an object (or a set of objects) has multiple hints of same hint-type,
2038          * only the last hint is valid and others are ignored in planning.
2039          * Hints except the last are marked as 'duplicated' to remember the order.
2040          */
2041         for (i = 0; i < hstate->nall_hints - 1; i++)
2042         {
2043                 Hint   *cur_hint = hstate->all_hints[i];
2044                 Hint   *next_hint = hstate->all_hints[i + 1];
2045
2046                 /*
2047                  * Leading hint is marked as 'duplicated' in transform_join_hints.
2048                  */
2049                 if (cur_hint->type == HINT_TYPE_LEADING &&
2050                         next_hint->type == HINT_TYPE_LEADING)
2051                         continue;
2052
2053                 /*
2054                  * Note that we need to pass addresses of hint pointers, because
2055                  * HintCmp is designed to sort array of Hint* by qsort.
2056                  */
2057                 if (HintCmp(&cur_hint, &next_hint) == 0)
2058                 {
2059                         hint_ereport(cur_hint->hint_str,
2060                                                  ("Conflict %s hint.", HintTypeName[cur_hint->type]));
2061                         cur_hint->state = HINT_STATE_DUPLICATION;
2062                 }
2063         }
2064
2065         /*
2066          * Make sure that per-type array pointers point proper position in the
2067          * array which consists of all hints.
2068          */
2069         hstate->scan_hints = (ScanMethodHint **) hstate->all_hints;
2070         hstate->join_hints = (JoinMethodHint **) (hstate->scan_hints +
2071                 hstate->num_hints[HINT_TYPE_SCAN_METHOD]);
2072         hstate->leading_hint = (LeadingHint **) (hstate->join_hints +
2073                 hstate->num_hints[HINT_TYPE_JOIN_METHOD]);
2074         hstate->set_hints = (SetHint **) (hstate->leading_hint +
2075                 hstate->num_hints[HINT_TYPE_LEADING]);
2076         hstate->rows_hints = (RowsHint **) (hstate->set_hints +
2077                 hstate->num_hints[HINT_TYPE_SET]);
2078         hstate->parallel_hints = (ParallelHint **) (hstate->set_hints +
2079                 hstate->num_hints[HINT_TYPE_ROWS]);
2080
2081         return hstate;
2082 }
2083
2084 /*
2085  * Parse inside of parentheses of scan-method hints.
2086  */
2087 static const char *
2088 ScanMethodHintParse(ScanMethodHint *hint, HintState *hstate, Query *parse,
2089                                         const char *str)
2090 {
2091         const char         *keyword = hint->base.keyword;
2092         HintKeyword             hint_keyword = hint->base.hint_keyword;
2093         List               *name_list = NIL;
2094         int                             length;
2095
2096         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
2097                 return NULL;
2098
2099         /* Parse relation name and index name(s) if given hint accepts. */
2100         length = list_length(name_list);
2101
2102         /* at least twp parameters required */
2103         if (length < 1)
2104         {
2105                 hint_ereport(str,
2106                                          ("%s hint requires a relation.",  hint->base.keyword));
2107                 hint->base.state = HINT_STATE_ERROR;
2108                 return str;
2109         }
2110
2111         hint->relname = linitial(name_list);
2112         hint->indexnames = list_delete_first(name_list);
2113
2114         /* check whether the hint accepts index name(s) */
2115         if (length > 1 && !SCAN_HINT_ACCEPTS_INDEX_NAMES(hint_keyword))
2116         {
2117                 hint_ereport(str,
2118                                          ("%s hint accepts only one relation.",
2119                                           hint->base.keyword));
2120                 hint->base.state = HINT_STATE_ERROR;
2121                 return str;
2122         }
2123
2124         /* Set a bit for specified hint. */
2125         switch (hint_keyword)
2126         {
2127                 case HINT_KEYWORD_SEQSCAN:
2128                         hint->enforce_mask = ENABLE_SEQSCAN;
2129                         break;
2130                 case HINT_KEYWORD_INDEXSCAN:
2131                         hint->enforce_mask = ENABLE_INDEXSCAN;
2132                         break;
2133                 case HINT_KEYWORD_INDEXSCANREGEXP:
2134                         hint->enforce_mask = ENABLE_INDEXSCAN;
2135                         hint->regexp = true;
2136                         break;
2137                 case HINT_KEYWORD_BITMAPSCAN:
2138                         hint->enforce_mask = ENABLE_BITMAPSCAN;
2139                         break;
2140                 case HINT_KEYWORD_BITMAPSCANREGEXP:
2141                         hint->enforce_mask = ENABLE_BITMAPSCAN;
2142                         hint->regexp = true;
2143                         break;
2144                 case HINT_KEYWORD_TIDSCAN:
2145                         hint->enforce_mask = ENABLE_TIDSCAN;
2146                         break;
2147                 case HINT_KEYWORD_NOSEQSCAN:
2148                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_SEQSCAN;
2149                         break;
2150                 case HINT_KEYWORD_NOINDEXSCAN:
2151                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_INDEXSCAN;
2152                         break;
2153                 case HINT_KEYWORD_NOBITMAPSCAN:
2154                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_BITMAPSCAN;
2155                         break;
2156                 case HINT_KEYWORD_NOTIDSCAN:
2157                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_TIDSCAN;
2158                         break;
2159                 case HINT_KEYWORD_INDEXONLYSCAN:
2160                         hint->enforce_mask = ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN;
2161                         break;
2162                 case HINT_KEYWORD_INDEXONLYSCANREGEXP:
2163                         hint->enforce_mask = ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN;
2164                         hint->regexp = true;
2165                         break;
2166                 case HINT_KEYWORD_NOINDEXONLYSCAN:
2167                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_INDEXONLYSCAN;
2168                         break;
2169                 default:
2170                         hint_ereport(str, ("Unrecognized hint keyword \"%s\".", keyword));
2171                         return NULL;
2172                         break;
2173         }
2174
2175         return str;
2176 }
2177
2178 static const char *
2179 JoinMethodHintParse(JoinMethodHint *hint, HintState *hstate, Query *parse,
2180                                         const char *str)
2181 {
2182         const char         *keyword = hint->base.keyword;
2183         HintKeyword             hint_keyword = hint->base.hint_keyword;
2184         List               *name_list = NIL;
2185
2186         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
2187                 return NULL;
2188
2189         hint->nrels = list_length(name_list);
2190
2191         if (hint->nrels > 0)
2192         {
2193                 ListCell   *l;
2194                 int                     i = 0;
2195
2196                 /*
2197                  * Transform relation names from list to array to sort them with qsort
2198                  * after.
2199                  */
2200                 hint->relnames = palloc(sizeof(char *) * hint->nrels);
2201                 foreach (l, name_list)
2202                 {
2203                         hint->relnames[i] = lfirst(l);
2204                         i++;
2205                 }
2206         }
2207
2208         list_free(name_list);
2209
2210         /* A join hint requires at least two relations */
2211         if (hint->nrels < 2)
2212         {
2213                 hint_ereport(str,
2214                                          ("%s hint requires at least two relations.",
2215                                           hint->base.keyword));
2216                 hint->base.state = HINT_STATE_ERROR;
2217                 return str;
2218         }
2219
2220         /* Sort hints in alphabetical order of relation names. */
2221         qsort(hint->relnames, hint->nrels, sizeof(char *), RelnameCmp);
2222
2223         switch (hint_keyword)
2224         {
2225                 case HINT_KEYWORD_NESTLOOP:
2226                         hint->enforce_mask = ENABLE_NESTLOOP;
2227                         break;
2228                 case HINT_KEYWORD_MERGEJOIN:
2229                         hint->enforce_mask = ENABLE_MERGEJOIN;
2230                         break;
2231                 case HINT_KEYWORD_HASHJOIN:
2232                         hint->enforce_mask = ENABLE_HASHJOIN;
2233                         break;
2234                 case HINT_KEYWORD_NONESTLOOP:
2235                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_NESTLOOP;
2236                         break;
2237                 case HINT_KEYWORD_NOMERGEJOIN:
2238                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_MERGEJOIN;
2239                         break;
2240                 case HINT_KEYWORD_NOHASHJOIN:
2241                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_HASHJOIN;
2242                         break;
2243                 default:
2244                         hint_ereport(str, ("Unrecognized hint keyword \"%s\".", keyword));
2245                         return NULL;
2246                         break;
2247         }
2248
2249         return str;
2250 }
2251
2252 static bool
2253 OuterInnerPairCheck(OuterInnerRels *outer_inner)
2254 {
2255         ListCell *l;
2256         if (outer_inner->outer_inner_pair == NIL)
2257         {
2258                 if (outer_inner->relation)
2259                         return true;
2260                 else
2261                         return false;
2262         }
2263
2264         if (list_length(outer_inner->outer_inner_pair) == 2)
2265         {
2266                 foreach(l, outer_inner->outer_inner_pair)
2267                 {
2268                         if (!OuterInnerPairCheck(lfirst(l)))
2269                                 return false;
2270                 }
2271         }
2272         else
2273                 return false;
2274
2275         return true;
2276 }
2277
2278 static List *
2279 OuterInnerList(OuterInnerRels *outer_inner)
2280 {
2281         List               *outer_inner_list = NIL;
2282         ListCell           *l;
2283         OuterInnerRels *outer_inner_rels;
2284
2285         foreach(l, outer_inner->outer_inner_pair)
2286         {
2287                 outer_inner_rels = (OuterInnerRels *)(lfirst(l));
2288
2289                 if (outer_inner_rels->relation != NULL)
2290                         outer_inner_list = lappend(outer_inner_list,
2291                                                                            outer_inner_rels->relation);
2292                 else
2293                         outer_inner_list = list_concat(outer_inner_list,
2294                                                                                    OuterInnerList(outer_inner_rels));
2295         }
2296         return outer_inner_list;
2297 }
2298
2299 static const char *
2300 LeadingHintParse(LeadingHint *hint, HintState *hstate, Query *parse,
2301                                  const char *str)
2302 {
2303         List               *name_list = NIL;
2304         OuterInnerRels *outer_inner = NULL;
2305
2306         if ((str = parse_parentheses_Leading(str, &name_list, &outer_inner)) ==
2307                 NULL)
2308                 return NULL;
2309
2310         if (outer_inner != NULL)
2311                 name_list = OuterInnerList(outer_inner);
2312
2313         hint->relations = name_list;
2314         hint->outer_inner = outer_inner;
2315
2316         /* A Leading hint requires at least two relations */
2317         if ( hint->outer_inner == NULL && list_length(hint->relations) < 2)
2318         {
2319                 hint_ereport(hint->base.hint_str,
2320                                          ("%s hint requires at least two relations.",
2321                                           HINT_LEADING));
2322                 hint->base.state = HINT_STATE_ERROR;
2323         }
2324         else if (hint->outer_inner != NULL &&
2325                          !OuterInnerPairCheck(hint->outer_inner))
2326         {
2327                 hint_ereport(hint->base.hint_str,
2328                                          ("%s hint requires two sets of relations when parentheses nests.",
2329                                           HINT_LEADING));
2330                 hint->base.state = HINT_STATE_ERROR;
2331         }
2332
2333         return str;
2334 }
2335
2336 static const char *
2337 SetHintParse(SetHint *hint, HintState *hstate, Query *parse, const char *str)
2338 {
2339         List   *name_list = NIL;
2340
2341         if ((str = parse_parentheses(str, &name_list, hint->base.hint_keyword))
2342                 == NULL)
2343                 return NULL;
2344
2345         hint->words = name_list;
2346
2347         /* We need both name and value to set GUC parameter. */
2348         if (list_length(name_list) == 2)
2349         {
2350                 hint->name = linitial(name_list);
2351                 hint->value = lsecond(name_list);
2352         }
2353         else
2354         {
2355                 hint_ereport(hint->base.hint_str,
2356                                          ("%s hint requires name and value of GUC parameter.",
2357                                           HINT_SET));
2358                 hint->base.state = HINT_STATE_ERROR;
2359         }
2360
2361         return str;
2362 }
2363
2364 static const char *
2365 RowsHintParse(RowsHint *hint, HintState *hstate, Query *parse,
2366                           const char *str)
2367 {
2368         HintKeyword             hint_keyword = hint->base.hint_keyword;
2369         List               *name_list = NIL;
2370         char               *rows_str;
2371         char               *end_ptr;
2372
2373         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
2374                 return NULL;
2375
2376         /* Last element must be rows specification */
2377         hint->nrels = list_length(name_list) - 1;
2378
2379         if (hint->nrels > 0)
2380         {
2381                 ListCell   *l;
2382                 int                     i = 0;
2383
2384                 /*
2385                  * Transform relation names from list to array to sort them with qsort
2386                  * after.
2387                  */
2388                 hint->relnames = palloc(sizeof(char *) * hint->nrels);
2389                 foreach (l, name_list)
2390                 {
2391                         if (hint->nrels <= i)
2392                                 break;
2393                         hint->relnames[i] = lfirst(l);
2394                         i++;
2395                 }
2396         }
2397
2398         /* Retieve rows estimation */
2399         rows_str = list_nth(name_list, hint->nrels);
2400         hint->rows_str = rows_str;              /* store as-is for error logging */
2401         if (rows_str[0] == '#')
2402         {
2403                 hint->value_type = RVT_ABSOLUTE;
2404                 rows_str++;
2405         }
2406         else if (rows_str[0] == '+')
2407         {
2408                 hint->value_type = RVT_ADD;
2409                 rows_str++;
2410         }
2411         else if (rows_str[0] == '-')
2412         {
2413                 hint->value_type = RVT_SUB;
2414                 rows_str++;
2415         }
2416         else if (rows_str[0] == '*')
2417         {
2418                 hint->value_type = RVT_MULTI;
2419                 rows_str++;
2420         }
2421         else
2422         {
2423                 hint_ereport(rows_str, ("Unrecognized rows value type notation."));
2424                 hint->base.state = HINT_STATE_ERROR;
2425                 return str;
2426         }
2427         hint->rows = strtod(rows_str, &end_ptr);
2428         if (*end_ptr)
2429         {
2430                 hint_ereport(rows_str,
2431                                          ("%s hint requires valid number as rows estimation.",
2432                                           hint->base.keyword));
2433                 hint->base.state = HINT_STATE_ERROR;
2434                 return str;
2435         }
2436
2437         /* A join hint requires at least two relations */
2438         if (hint->nrels < 2)
2439         {
2440                 hint_ereport(str,
2441                                          ("%s hint requires at least two relations.",
2442                                           hint->base.keyword));
2443                 hint->base.state = HINT_STATE_ERROR;
2444                 return str;
2445         }
2446
2447         list_free(name_list);
2448
2449         /* Sort relnames in alphabetical order. */
2450         qsort(hint->relnames, hint->nrels, sizeof(char *), RelnameCmp);
2451
2452         return str;
2453 }
2454
2455 static const char *
2456 ParallelHintParse(ParallelHint *hint, HintState *hstate, Query *parse,
2457                                   const char *str)
2458 {
2459         HintKeyword             hint_keyword = hint->base.hint_keyword;
2460         List               *name_list = NIL;
2461         int                             length;
2462         char   *end_ptr;
2463         int             nworkers;
2464         bool    force_parallel = false;
2465
2466         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
2467                 return NULL;
2468
2469         /* Parse relation name and index name(s) if given hint accepts. */
2470         length = list_length(name_list);
2471
2472         if (length < 2 || length > 3)
2473         {
2474                 hint_ereport(")",
2475                                          ("wrong number of arguments (%d): %s",
2476                                           length,  hint->base.keyword));
2477                 hint->base.state = HINT_STATE_ERROR;
2478                 return str;
2479         }
2480
2481         hint->relname = linitial(name_list);
2482
2483         /* The second parameter is number of workers */
2484         hint->nworkers_str = list_nth(name_list, 1);
2485         nworkers = strtod(hint->nworkers_str, &end_ptr);
2486         if (*end_ptr || nworkers < 0 || nworkers > max_worker_processes)
2487         {
2488                 if (*end_ptr)
2489                         hint_ereport(hint->nworkers_str,
2490                                                  ("number of workers must be a number: %s",
2491                                                   hint->base.keyword));
2492                 else if (nworkers < 0)
2493                         hint_ereport(hint->nworkers_str,
2494                                                  ("number of workers must be positive: %s",
2495                                                   hint->base.keyword));
2496                 else if (nworkers > max_worker_processes)
2497                         hint_ereport(hint->nworkers_str,
2498                                                  ("number of workers = %d is larger than max_worker_processes(%d): %s",
2499                                                   nworkers, max_worker_processes, hint->base.keyword));
2500
2501                 hint->base.state = HINT_STATE_ERROR;
2502         }
2503
2504         hint->nworkers = nworkers;
2505
2506         /* optional third parameter is specified */
2507         if (length == 3)
2508         {
2509                 const char *modeparam = (const char *)list_nth(name_list, 2);
2510                 if (pg_strcasecmp(modeparam, "hard") == 0)
2511                         force_parallel = true;
2512                 else if (pg_strcasecmp(modeparam, "soft") != 0)
2513                 {
2514                         hint_ereport(modeparam,
2515                                                  ("enforcement must be soft or hard: %s",
2516                                                          hint->base.keyword));
2517                         hint->base.state = HINT_STATE_ERROR;
2518                 }
2519         }
2520
2521         hint->force_parallel = force_parallel;
2522
2523         if (hint->base.state != HINT_STATE_ERROR &&
2524                 nworkers > max_hint_nworkers)
2525                 max_hint_nworkers = nworkers;
2526
2527         return str;
2528 }
2529
2530 /*
2531  * set GUC parameter functions
2532  */
2533
2534 static int
2535 get_current_scan_mask()
2536 {
2537         int mask = 0;
2538
2539         if (enable_seqscan)
2540                 mask |= ENABLE_SEQSCAN;
2541         if (enable_indexscan)
2542                 mask |= ENABLE_INDEXSCAN;
2543         if (enable_bitmapscan)
2544                 mask |= ENABLE_BITMAPSCAN;
2545         if (enable_tidscan)
2546                 mask |= ENABLE_TIDSCAN;
2547         if (enable_indexonlyscan)
2548                 mask |= ENABLE_INDEXONLYSCAN;
2549
2550         return mask;
2551 }
2552
2553 static int
2554 get_current_join_mask()
2555 {
2556         int mask = 0;
2557
2558         if (enable_nestloop)
2559                 mask |= ENABLE_NESTLOOP;
2560         if (enable_mergejoin)
2561                 mask |= ENABLE_MERGEJOIN;
2562         if (enable_hashjoin)
2563                 mask |= ENABLE_HASHJOIN;
2564
2565         return mask;
2566 }
2567
2568 /*
2569  * Sets GUC prameters without throwing exception. Reutrns false if something
2570  * wrong.
2571  */
2572 static int
2573 set_config_option_noerror(const char *name, const char *value,
2574                                                   GucContext context, GucSource source,
2575                                                   GucAction action, bool changeVal, int elevel)
2576 {
2577         int                             result = 0;
2578         MemoryContext   ccxt = CurrentMemoryContext;
2579
2580         PG_TRY();
2581         {
2582                 result = set_config_option(name, value, context, source,
2583                                                                    action, changeVal, 0, false);
2584         }
2585         PG_CATCH();
2586         {
2587                 ErrorData          *errdata;
2588
2589                 /* Save error info */
2590                 MemoryContextSwitchTo(ccxt);
2591                 errdata = CopyErrorData();
2592                 FlushErrorState();
2593
2594                 ereport(elevel,
2595                                 (errcode(errdata->sqlerrcode),
2596                                  errmsg("%s", errdata->message),
2597                                  errdata->detail ? errdetail("%s", errdata->detail) : 0,
2598                                  errdata->hint ? errhint("%s", errdata->hint) : 0));
2599                 msgqno = qno;
2600                 FreeErrorData(errdata);
2601         }
2602         PG_END_TRY();
2603
2604         return result;
2605 }
2606
2607 /*
2608  * Sets GUC parameter of int32 type without throwing exceptions. Returns false
2609  * if something wrong.
2610  */
2611 static int
2612 set_config_int32_option(const char *name, int32 value, GucContext context)
2613 {
2614         char buf[16];   /* enough for int32 */
2615
2616         if (snprintf(buf, 16, "%d", value) < 0)
2617         {
2618                 ereport(pg_hint_plan_parse_message_level,
2619                                 (errmsg ("Failed to convert integer to string: %d", value)));
2620                 return false;
2621         }
2622
2623         return
2624                 set_config_option_noerror(name, buf, context,
2625                                                                   PGC_S_SESSION, GUC_ACTION_SAVE, true,
2626                                                                   pg_hint_plan_parse_message_level);
2627 }
2628
2629 /* setup scan method enforcement according to given options */
2630 static void
2631 setup_guc_enforcement(SetHint **options, int noptions, GucContext context)
2632 {
2633         int     i;
2634
2635         for (i = 0; i < noptions; i++)
2636         {
2637                 SetHint    *hint = options[i];
2638                 int                     result;
2639
2640                 if (!hint_state_enabled(hint))
2641                         continue;
2642
2643                 result = set_config_option_noerror(hint->name, hint->value, context,
2644                                                                                    PGC_S_SESSION, GUC_ACTION_SAVE, true,
2645                                                                                    pg_hint_plan_parse_message_level);
2646                 if (result != 0)
2647                         hint->base.state = HINT_STATE_USED;
2648                 else
2649                         hint->base.state = HINT_STATE_ERROR;
2650         }
2651
2652         return;
2653 }
2654
2655 /*
2656  * Setup parallel execution environment.
2657  *
2658  * If hint is not NULL, set up using it, elsewise reset to initial environment.
2659  */
2660 static void
2661 setup_parallel_plan_enforcement(ParallelHint *hint, HintState *state)
2662 {
2663         if (hint)
2664         {
2665                 hint->base.state = HINT_STATE_USED;
2666                 set_config_int32_option("max_parallel_workers_per_gather",
2667                                                                 hint->nworkers, state->context);
2668         }
2669         else
2670                 set_config_int32_option("max_parallel_workers_per_gather",
2671                                                                 state->init_nworkers, state->context);
2672
2673         /* force means that enforce parallel as far as possible */
2674         if (hint && hint->force_parallel && hint->nworkers > 0)
2675         {
2676                 set_config_int32_option("parallel_tuple_cost", 0, state->context);
2677                 set_config_int32_option("parallel_setup_cost", 0, state->context);
2678                 set_config_int32_option("min_parallel_table_scan_size", 0,
2679                                                                 state->context);
2680                 set_config_int32_option("min_parallel_index_scan_size", 0,
2681                                                                 state->context);
2682         }
2683         else
2684         {
2685                 set_config_int32_option("parallel_tuple_cost",
2686                                                                 state->init_paratup_cost, state->context);
2687                 set_config_int32_option("parallel_setup_cost",
2688                                                                 state->init_parasetup_cost, state->context);
2689                 set_config_int32_option("min_parallel_table_scan_size",
2690                                                                 state->init_min_para_tablescan_size,
2691                                                                 state->context);
2692                 set_config_int32_option("min_parallel_index_scan_size",
2693                                                                 state->init_min_para_indexscan_size,
2694                                                                 state->context);
2695         }
2696 }
2697
2698 #define SET_CONFIG_OPTION(name, type_bits) \
2699         set_config_option_noerror((name), \
2700                 (mask & (type_bits)) ? "true" : "false", \
2701                 context, PGC_S_SESSION, GUC_ACTION_SAVE, true, ERROR)
2702
2703
2704 /*
2705  * Setup GUC environment to enforce scan methods. If scanhint is NULL, reset
2706  * GUCs to the saved state in state.
2707  */
2708 static void
2709 setup_scan_method_enforcement(ScanMethodHint *scanhint, HintState *state)
2710 {
2711         unsigned char   enforce_mask = state->init_scan_mask;
2712         GucContext              context = state->context;
2713         unsigned char   mask;
2714
2715         if (scanhint)
2716         {
2717                 enforce_mask = scanhint->enforce_mask;
2718                 scanhint->base.state = HINT_STATE_USED;
2719         }
2720
2721         if (enforce_mask == ENABLE_SEQSCAN || enforce_mask == ENABLE_INDEXSCAN ||
2722                 enforce_mask == ENABLE_BITMAPSCAN || enforce_mask == ENABLE_TIDSCAN
2723                 || enforce_mask == (ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN)
2724                 )
2725                 mask = enforce_mask;
2726         else
2727                 mask = enforce_mask & current_hint_state->init_scan_mask;
2728
2729         SET_CONFIG_OPTION("enable_seqscan", ENABLE_SEQSCAN);
2730         SET_CONFIG_OPTION("enable_indexscan", ENABLE_INDEXSCAN);
2731         SET_CONFIG_OPTION("enable_bitmapscan", ENABLE_BITMAPSCAN);
2732         SET_CONFIG_OPTION("enable_tidscan", ENABLE_TIDSCAN);
2733         SET_CONFIG_OPTION("enable_indexonlyscan", ENABLE_INDEXONLYSCAN);
2734 }
2735
2736 static void
2737 set_join_config_options(unsigned char enforce_mask, GucContext context)
2738 {
2739         unsigned char   mask;
2740
2741         if (enforce_mask == ENABLE_NESTLOOP || enforce_mask == ENABLE_MERGEJOIN ||
2742                 enforce_mask == ENABLE_HASHJOIN)
2743                 mask = enforce_mask;
2744         else
2745                 mask = enforce_mask & current_hint_state->init_join_mask;
2746
2747         SET_CONFIG_OPTION("enable_nestloop", ENABLE_NESTLOOP);
2748         SET_CONFIG_OPTION("enable_mergejoin", ENABLE_MERGEJOIN);
2749         SET_CONFIG_OPTION("enable_hashjoin", ENABLE_HASHJOIN);
2750 }
2751
2752 /*
2753  * Push a hint into hint stack which is implemented with List struct.  Head of
2754  * list is top of stack.
2755  */
2756 static void
2757 push_hint(HintState *hstate)
2758 {
2759         /* Prepend new hint to the list means pushing to stack. */
2760         HintStateStack = lcons(hstate, HintStateStack);
2761
2762         /* Pushed hint is the one which should be used hereafter. */
2763         current_hint_state = hstate;
2764 }
2765
2766 /* Pop a hint from hint stack.  Popped hint is automatically discarded. */
2767 static void
2768 pop_hint(void)
2769 {
2770         /* Hint stack must not be empty. */
2771         if(HintStateStack == NIL)
2772                 elog(ERROR, "hint stack is empty");
2773
2774         /*
2775          * Take a hint at the head from the list, and free it.  Switch
2776          * current_hint_state to point new head (NULL if the list is empty).
2777          */
2778         HintStateStack = list_delete_first(HintStateStack);
2779         HintStateDelete(current_hint_state);
2780         if(HintStateStack == NIL)
2781                 current_hint_state = NULL;
2782         else
2783                 current_hint_state = (HintState *) lfirst(list_head(HintStateStack));
2784 }
2785
2786 /*
2787  * Retrieve and store hint string from given query or from the hint table.
2788  */
2789 static void
2790 get_current_hint_string(ParseState *pstate, Query *query)
2791 {
2792         const char *query_str;
2793         MemoryContext   oldcontext;
2794
2795         /* do nothing under hint table search */
2796         if (hint_inhibit_level > 0)
2797                 return;
2798
2799         /* We alredy have one, don't parse it again. */
2800         if (current_hint_retrieved)
2801                 return;
2802
2803         /* Don't parse the current query hereafter */
2804         current_hint_retrieved = true;
2805
2806         if (!pg_hint_plan_enable_hint)
2807         {
2808                 if (current_hint_str)
2809                 {
2810                         pfree((void *)current_hint_str);
2811                         current_hint_str = NULL;
2812                 }
2813                 return;
2814         }
2815
2816         /* increment the query number */
2817         qnostr[0] = 0;
2818         if (debug_level > 1)
2819                 snprintf(qnostr, sizeof(qnostr), "[qno=0x%x]", qno++);
2820         qno++;
2821
2822         /* search the hint table for a hint if requested */
2823         if (pg_hint_plan_enable_hint_table)
2824         {
2825                 int                             query_len;
2826                 pgssJumbleState jstate;
2827                 Query              *jumblequery;
2828                 char               *normalized_query = NULL;
2829
2830                 query_str = get_query_string(pstate, query, &jumblequery);
2831
2832                 /* If this query is not for hint, just return */
2833                 if (!query_str)
2834                         return;
2835
2836                 /* clear the previous hint string */
2837                 if (current_hint_str)
2838                 {
2839                         pfree((void *)current_hint_str);
2840                         current_hint_str = NULL;
2841                 }
2842
2843                 if (jumblequery)
2844                 {
2845                         /*
2846                          * XXX: normalization code is copied from pg_stat_statements.c.
2847                          * Make sure to keep up-to-date with it.
2848                          */
2849                         jstate.jumble = (unsigned char *) palloc(JUMBLE_SIZE);
2850                         jstate.jumble_len = 0;
2851                         jstate.clocations_buf_size = 32;
2852                         jstate.clocations = (pgssLocationLen *)
2853                                 palloc(jstate.clocations_buf_size * sizeof(pgssLocationLen));
2854                         jstate.clocations_count = 0;
2855
2856                         JumbleQuery(&jstate, jumblequery);
2857
2858                         /*
2859                          * Normalize the query string by replacing constants with '?'
2860                          */
2861                         /*
2862                          * Search hint string which is stored keyed by query string
2863                          * and application name.  The query string is normalized to allow
2864                          * fuzzy matching.
2865                          *
2866                          * Adding 1 byte to query_len ensures that the returned string has
2867                          * a terminating NULL.
2868                          */
2869                         query_len = strlen(query_str) + 1;
2870                         normalized_query =
2871                                 generate_normalized_query(&jstate, query_str, 0, &query_len,
2872                                                                                   GetDatabaseEncoding());
2873
2874                         /*
2875                          * find a hint for the normalized query. the result should be in
2876                          * TopMemoryContext
2877                          */
2878                         oldcontext = MemoryContextSwitchTo(TopMemoryContext);
2879                         current_hint_str =
2880                                 get_hints_from_table(normalized_query, application_name);
2881                         MemoryContextSwitchTo(oldcontext);
2882
2883                         if (debug_level > 1)
2884                         {
2885                                 if (current_hint_str)
2886                                         ereport(pg_hint_plan_debug_message_level,
2887                                                         (errmsg("pg_hint_plan[qno=0x%x]: "
2888                                                                         "post_parse_analyze_hook: "
2889                                                                         "hints from table: \"%s\": "
2890                                                                         "normalized_query=\"%s\", "
2891                                                                         "application name =\"%s\"",
2892                                                                         qno, current_hint_str,
2893                                                                         normalized_query, application_name),
2894                                                          errhidestmt(msgqno != qno),
2895                                                          errhidecontext(msgqno != qno)));
2896                                 else
2897                                         ereport(pg_hint_plan_debug_message_level,
2898                                                         (errmsg("pg_hint_plan[qno=0x%x]: "
2899                                                                         "no match found in table:  "
2900                                                                         "application name = \"%s\", "
2901                                                                         "normalized_query=\"%s\"",
2902                                                                         qno, application_name,
2903                                                                         normalized_query),
2904                                                          errhidestmt(msgqno != qno),
2905                                                          errhidecontext(msgqno != qno)));
2906
2907                                 msgqno = qno;
2908                         }
2909                 }
2910
2911                 /* retrun if we have hint here */
2912                 if (current_hint_str)
2913                         return;
2914         }
2915         else
2916                 query_str = get_query_string(pstate, query, NULL);
2917
2918         if (query_str)
2919         {
2920                 /*
2921                  * get hints from the comment. However we may have the same query
2922                  * string with the previous call, but the extra comparison seems no
2923                  * use..
2924                  */
2925                 if (current_hint_str)
2926                         pfree((void *)current_hint_str);
2927
2928                 oldcontext = MemoryContextSwitchTo(TopMemoryContext);
2929                 current_hint_str = get_hints_from_comment(query_str);
2930                 MemoryContextSwitchTo(oldcontext);
2931         }
2932         else
2933         {
2934                 /*
2935                  * Failed to get query. We would be in fetching invalidated
2936                  * plancache. Try the next chance.
2937                  */
2938                 current_hint_retrieved = false;
2939         }
2940
2941         if (debug_level > 1)
2942         {
2943                 if (debug_level == 1 && query_str && debug_query_string &&
2944                         strcmp(query_str, debug_query_string))
2945                         ereport(pg_hint_plan_debug_message_level,
2946                                         (errmsg("hints in comment=\"%s\"",
2947                                                         current_hint_str ? current_hint_str : "(none)"),
2948                                          errhidestmt(msgqno != qno),
2949                                          errhidecontext(msgqno != qno)));
2950                 else
2951                         ereport(pg_hint_plan_debug_message_level,
2952                                         (errmsg("hints in comment=\"%s\", query=\"%s\", debug_query_string=\"%s\"",
2953                                                         current_hint_str ? current_hint_str : "(none)",
2954                                                         query_str ? query_str : "(none)",
2955                                                         debug_query_string ? debug_query_string : "(none)"),
2956                                          errhidestmt(msgqno != qno),
2957                                          errhidecontext(msgqno != qno)));
2958                 msgqno = qno;
2959         }
2960 }
2961
2962 /*
2963  * Retrieve hint string from the current query.
2964  */
2965 static void
2966 pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query)
2967 {
2968         if (prev_post_parse_analyze_hook)
2969                 prev_post_parse_analyze_hook(pstate, query);
2970
2971         /* always retrieve hint from the top-level query string */
2972         if (plpgsql_recurse_level == 0)
2973                 current_hint_retrieved = false;
2974
2975         get_current_hint_string(pstate, query);
2976 }
2977
2978 /*
2979  * We need to reset current_hint_retrieved flag always when a command execution
2980  * is finished. This is true even for a pure utility command that doesn't
2981  * involve planning phase.
2982  */
2983 static void
2984 pg_hint_plan_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
2985                                         ProcessUtilityContext context,
2986                                         ParamListInfo params, QueryEnvironment *queryEnv,
2987                                         DestReceiver *dest, char *completionTag)
2988 {
2989         if (prev_ProcessUtility_hook)
2990                 prev_ProcessUtility_hook(pstmt, queryString, context, params, queryEnv,
2991                                                                  dest, completionTag);
2992         else
2993                 standard_ProcessUtility(pstmt, queryString, context, params, queryEnv,
2994                                                                  dest, completionTag);
2995
2996         if (plpgsql_recurse_level == 0)
2997                 current_hint_retrieved = false;
2998 }
2999
3000 /*
3001  * Read and set up hint information
3002  */
3003 static PlannedStmt *
3004 pg_hint_plan_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
3005 {
3006         int                             save_nestlevel;
3007         PlannedStmt        *result;
3008         HintState          *hstate;
3009         const char         *prev_hint_str = NULL;
3010
3011         /*
3012          * Use standard planner if pg_hint_plan is disabled or current nesting
3013          * depth is nesting depth of SPI calls. Other hook functions try to change
3014          * plan with current_hint_state if any, so set it to NULL.
3015          */
3016         if (!pg_hint_plan_enable_hint || hint_inhibit_level > 0)
3017         {
3018                 if (debug_level > 1)
3019                         ereport(pg_hint_plan_debug_message_level,
3020                                         (errmsg ("pg_hint_plan%s: planner: enable_hint=%d,"
3021                                                          " hint_inhibit_level=%d",
3022                                                          qnostr, pg_hint_plan_enable_hint,
3023                                                          hint_inhibit_level),
3024                                          errhidestmt(msgqno != qno)));
3025                 msgqno = qno;
3026
3027                 goto standard_planner_proc;
3028         }
3029
3030         /*
3031          * Support for nested plpgsql functions. This is quite ugly but this is the
3032          * only point I could find where I can get the query string.
3033          */
3034         if (plpgsql_recurse_level > 0 &&
3035                 error_context_stack && error_context_stack->arg)
3036         {
3037                 MemoryContext oldcontext;
3038
3039                 oldcontext = MemoryContextSwitchTo(TopMemoryContext);
3040                 current_hint_str =
3041                         get_hints_from_comment((char *)error_context_stack->arg);
3042                 MemoryContextSwitchTo(oldcontext);
3043         }
3044
3045         /*
3046          * Query execution in extended protocol can be started without the analyze
3047          * phase. In the case retrieve hint string here.
3048          */
3049         if (!current_hint_str)
3050                 get_current_hint_string(NULL, parse);
3051
3052         /* No hint, go the normal way */
3053         if (!current_hint_str)
3054                 goto standard_planner_proc;
3055
3056         /* parse the hint into hint state struct */
3057         hstate = create_hintstate(parse, pstrdup(current_hint_str));
3058
3059         /* run standard planner if the statement has not valid hint */
3060         if (!hstate)
3061                 goto standard_planner_proc;
3062
3063         /*
3064          * Push new hint struct to the hint stack to disable previous hint context.
3065          */
3066         push_hint(hstate);
3067
3068         /*  Set scan enforcement here. */
3069         save_nestlevel = NewGUCNestLevel();
3070
3071         /* Apply Set hints, then save it as the initial state  */
3072         setup_guc_enforcement(current_hint_state->set_hints,
3073                                                    current_hint_state->num_hints[HINT_TYPE_SET],
3074                                                    current_hint_state->context);
3075
3076         current_hint_state->init_scan_mask = get_current_scan_mask();
3077         current_hint_state->init_join_mask = get_current_join_mask();
3078         current_hint_state->init_min_para_tablescan_size =
3079                 min_parallel_table_scan_size;
3080         current_hint_state->init_min_para_indexscan_size =
3081                 min_parallel_index_scan_size;
3082         current_hint_state->init_paratup_cost = parallel_tuple_cost;
3083         current_hint_state->init_parasetup_cost = parallel_setup_cost;
3084
3085         /*
3086          * max_parallel_workers_per_gather should be non-zero here if Workers hint
3087          * is specified.
3088          */
3089         if (max_hint_nworkers > 0 && max_parallel_workers_per_gather < 1)
3090                 set_config_int32_option("max_parallel_workers_per_gather",
3091                                                                 1, current_hint_state->context);
3092         current_hint_state->init_nworkers = max_parallel_workers_per_gather;
3093
3094         if (debug_level > 1)
3095         {
3096                 ereport(pg_hint_plan_debug_message_level,
3097                                 (errhidestmt(msgqno != qno),
3098                                  errmsg("pg_hint_plan%s: planner", qnostr)));
3099                 msgqno = qno;
3100         }
3101
3102         /*
3103          * The planner call below may replace current_hint_str. Store and restore
3104          * it so that the subsequent planning in the upper level doesn't get
3105          * confused.
3106          */
3107         recurse_level++;
3108         prev_hint_str = current_hint_str;
3109         current_hint_str = NULL;
3110
3111         /*
3112          * Use PG_TRY mechanism to recover GUC parameters and current_hint_state to
3113          * the state when this planner started when error occurred in planner.
3114          */
3115         PG_TRY();
3116         {
3117                 if (prev_planner)
3118                         result = (*prev_planner) (parse, cursorOptions, boundParams);
3119                 else
3120                         result = standard_planner(parse, cursorOptions, boundParams);
3121
3122                 current_hint_str = prev_hint_str;
3123                 recurse_level--;
3124         }
3125         PG_CATCH();
3126         {
3127                 /*
3128                  * Rollback changes of GUC parameters, and pop current hint context
3129                  * from hint stack to rewind the state.
3130                  */
3131                 current_hint_str = prev_hint_str;
3132                 recurse_level--;
3133                 AtEOXact_GUC(true, save_nestlevel);
3134                 pop_hint();
3135                 PG_RE_THROW();
3136         }
3137         PG_END_TRY();
3138
3139
3140         /*
3141          * current_hint_str is useless after planning of the top-level query.
3142          */
3143         if (recurse_level < 1 && current_hint_str)
3144         {
3145                 pfree((void *)current_hint_str);
3146                 current_hint_str = NULL;
3147                 current_hint_retrieved = false;
3148         }
3149
3150         /* Print hint in debug mode. */
3151         if (debug_level == 1)
3152                 HintStateDump(current_hint_state);
3153         else if (debug_level > 1)
3154                 HintStateDump2(current_hint_state);
3155
3156         /*
3157          * Rollback changes of GUC parameters, and pop current hint context from
3158          * hint stack to rewind the state.
3159          */
3160         AtEOXact_GUC(true, save_nestlevel);
3161         pop_hint();
3162
3163         return result;
3164
3165 standard_planner_proc:
3166         if (debug_level > 1)
3167         {
3168                 ereport(pg_hint_plan_debug_message_level,
3169                                 (errhidestmt(msgqno != qno),
3170                                  errmsg("pg_hint_plan%s: planner: no valid hint",
3171                                                 qnostr)));
3172                 msgqno = qno;
3173         }
3174         current_hint_state = NULL;
3175         if (prev_planner)
3176                 return (*prev_planner) (parse, cursorOptions, boundParams);
3177         else
3178                 return standard_planner(parse, cursorOptions, boundParams);
3179 }
3180
3181 /*
3182  * Find scan method hint to be applied to the given relation
3183  *
3184  */
3185 static ScanMethodHint *
3186 find_scan_hint(PlannerInfo *root, Index relid)
3187 {
3188         RelOptInfo         *rel;
3189         RangeTblEntry  *rte;
3190         ScanMethodHint  *real_name_hint = NULL;
3191         ScanMethodHint  *alias_hint = NULL;
3192         int                             i;
3193
3194         /* This should not be a join rel */
3195         Assert(relid > 0);
3196         rel = root->simple_rel_array[relid];
3197
3198         /*
3199          * This function is called for any RelOptInfo or its inheritance parent if
3200          * any. If we are called from inheritance planner, the RelOptInfo for the
3201          * parent of target child relation is not set in the planner info.
3202          *
3203          * Otherwise we should check that the reloptinfo is base relation or
3204          * inheritance children.
3205          */
3206         if (rel &&
3207                 rel->reloptkind != RELOPT_BASEREL &&
3208                 rel->reloptkind != RELOPT_OTHER_MEMBER_REL)
3209                 return NULL;
3210
3211         /*
3212          * This is baserel or appendrel children. We can refer to RangeTblEntry.
3213          */
3214         rte = root->simple_rte_array[relid];
3215         Assert(rte);
3216
3217         /* We don't hint on other than relation and foreign tables */
3218         if (rte->rtekind != RTE_RELATION ||
3219                 rte->relkind == RELKIND_FOREIGN_TABLE)
3220                 return NULL;
3221
3222         /* Find scan method hint, which matches given names, from the list. */
3223         for (i = 0; i < current_hint_state->num_hints[HINT_TYPE_SCAN_METHOD]; i++)
3224         {
3225                 ScanMethodHint *hint = current_hint_state->scan_hints[i];
3226
3227                 /* We ignore disabled hints. */
3228                 if (!hint_state_enabled(hint))
3229                         continue;
3230
3231                 if (!alias_hint &&
3232                         RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
3233                         alias_hint = hint;
3234
3235                 /* check the real name for appendrel children */
3236                 if (!real_name_hint &&
3237                         rel && rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
3238                 {
3239                         char *realname = get_rel_name(rte->relid);
3240
3241                         if (realname && RelnameCmp(&realname, &hint->relname) == 0)
3242                                 real_name_hint = hint;
3243                 }
3244
3245                 /* No more match expected, break  */
3246                 if(alias_hint && real_name_hint)
3247                         break;
3248         }
3249
3250         /* real name match precedes alias match */
3251         if (real_name_hint)
3252                 return real_name_hint;
3253
3254         return alias_hint;
3255 }
3256
3257 static ParallelHint *
3258 find_parallel_hint(PlannerInfo *root, Index relid)
3259 {
3260         RelOptInfo         *rel;
3261         RangeTblEntry  *rte;
3262         ParallelHint    *real_name_hint = NULL;
3263         ParallelHint    *alias_hint = NULL;
3264         int                             i;
3265
3266         /* This should not be a join rel */
3267         Assert(relid > 0);
3268         rel = root->simple_rel_array[relid];
3269
3270         /*
3271          * Parallel planning is appliable only on base relation, which has
3272          * RelOptInfo.
3273          */
3274         if (!rel)
3275                 return NULL;
3276
3277         /*
3278          * We have set root->glob->parallelModeOK if needed. What we should do here
3279          * is just following the decision of planner.
3280          */
3281         if (!rel->consider_parallel)
3282                 return NULL;
3283
3284         /*
3285          * This is baserel or appendrel children. We can refer to RangeTblEntry.
3286          */
3287         rte = root->simple_rte_array[relid];
3288         Assert(rte);
3289
3290         /* Find parallel method hint, which matches given names, from the list. */
3291         for (i = 0; i < current_hint_state->num_hints[HINT_TYPE_PARALLEL]; i++)
3292         {
3293                 ParallelHint *hint = current_hint_state->parallel_hints[i];
3294
3295                 /* We ignore disabled hints. */
3296                 if (!hint_state_enabled(hint))
3297                         continue;
3298
3299                 if (!alias_hint &&
3300                         RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
3301                         alias_hint = hint;
3302
3303                 /* check the real name for appendrel children */
3304                 if (!real_name_hint &&
3305                         rel && rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
3306                 {
3307                         char *realname = get_rel_name(rte->relid);
3308
3309                         if (realname && RelnameCmp(&realname, &hint->relname) == 0)
3310                                 real_name_hint = hint;
3311                 }
3312
3313                 /* No more match expected, break  */
3314                 if(alias_hint && real_name_hint)
3315                         break;
3316         }
3317
3318         /* real name match precedes alias match */
3319         if (real_name_hint)
3320                 return real_name_hint;
3321
3322         return alias_hint;
3323 }
3324
3325 /*
3326  * regexeq
3327  *
3328  * Returns TRUE on match, FALSE on no match.
3329  *
3330  *   s1 --- the data to match against
3331  *   s2 --- the pattern
3332  *
3333  * Because we copy s1 to NameData, make the size of s1 less than NAMEDATALEN.
3334  */
3335 static bool
3336 regexpeq(const char *s1, const char *s2)
3337 {
3338         NameData        name;
3339         text       *regexp;
3340         Datum           result;
3341
3342         strcpy(name.data, s1);
3343         regexp = cstring_to_text(s2);
3344
3345         result = DirectFunctionCall2Coll(nameregexeq,
3346                                                                          DEFAULT_COLLATION_OID,
3347                                                                          NameGetDatum(&name),
3348                                                                          PointerGetDatum(regexp));
3349         return DatumGetBool(result);
3350 }
3351
3352
3353 /* Remove indexes instructed not to use by hint. */
3354 static void
3355 restrict_indexes(PlannerInfo *root, ScanMethodHint *hint, RelOptInfo *rel,
3356                            bool using_parent_hint)
3357 {
3358         ListCell           *cell;
3359         ListCell           *prev;
3360         ListCell           *next;
3361         StringInfoData  buf;
3362         RangeTblEntry  *rte = root->simple_rte_array[rel->relid];
3363         Oid                             relationObjectId = rte->relid;
3364
3365         /*
3366          * We delete all the IndexOptInfo list and prevent you from being usable by
3367          * a scan.
3368          */
3369         if (hint->enforce_mask == ENABLE_SEQSCAN ||
3370                 hint->enforce_mask == ENABLE_TIDSCAN)
3371         {
3372                 list_free_deep(rel->indexlist);
3373                 rel->indexlist = NIL;
3374                 hint->base.state = HINT_STATE_USED;
3375
3376                 return;
3377         }
3378
3379         /*
3380          * When a list of indexes is not specified, we just use all indexes.
3381          */
3382         if (hint->indexnames == NIL)
3383                 return;
3384
3385         /*
3386          * Leaving only an specified index, we delete it from a IndexOptInfo list
3387          * other than it.
3388          */
3389         prev = NULL;
3390         if (debug_level > 0)
3391                 initStringInfo(&buf);
3392
3393         for (cell = list_head(rel->indexlist); cell; cell = next)
3394         {
3395                 IndexOptInfo   *info = (IndexOptInfo *) lfirst(cell);
3396                 char               *indexname = get_rel_name(info->indexoid);
3397                 ListCell           *l;
3398                 bool                    use_index = false;
3399
3400                 next = lnext(cell);
3401
3402                 foreach(l, hint->indexnames)
3403                 {
3404                         char   *hintname = (char *) lfirst(l);
3405                         bool    result;
3406
3407                         if (hint->regexp)
3408                                 result = regexpeq(indexname, hintname);
3409                         else
3410                                 result = RelnameCmp(&indexname, &hintname) == 0;
3411
3412                         if (result)
3413                         {
3414                                 use_index = true;
3415                                 if (debug_level > 0)
3416                                 {
3417                                         appendStringInfoCharMacro(&buf, ' ');
3418                                         quote_value(&buf, indexname);
3419                                 }
3420
3421                                 break;
3422                         }
3423                 }
3424
3425                 /*
3426                  * Apply index restriction of parent hint to children. Since index
3427                  * inheritance is not explicitly described we should search for an
3428                  * children's index with the same definition to that of the parent.
3429                  */
3430                 if (using_parent_hint && !use_index)
3431                 {
3432                         foreach(l, current_hint_state->parent_index_infos)
3433                         {
3434                                 int                                     i;
3435                                 HeapTuple                       ht_idx;
3436                                 ParentIndexInfo    *p_info = (ParentIndexInfo *)lfirst(l);
3437
3438                                 /*
3439                                  * we check the 'same' index by comparing uniqueness, access
3440                                  * method and index key columns.
3441                                  */
3442                                 if (p_info->indisunique != info->unique ||
3443                                         p_info->method != info->relam ||
3444                                         list_length(p_info->column_names) != info->ncolumns)
3445                                         continue;
3446
3447                                 /* Check if index key columns match */
3448                                 for (i = 0; i < info->ncolumns; i++)
3449                                 {
3450                                         char       *c_attname = NULL;
3451                                         char       *p_attname = NULL;
3452
3453                                         p_attname = list_nth(p_info->column_names, i);
3454
3455                                         /*
3456                                          * if both of the key of the same position are expressions,
3457                                          * ignore them for now and check later.
3458                                          */
3459                                         if (info->indexkeys[i] == 0 && !p_attname)
3460                                                 continue;
3461
3462                                         /* deny if one is expression while another is not */
3463                                         if (info->indexkeys[i] == 0 || !p_attname)
3464                                                 break;
3465
3466                                         c_attname = get_attname(relationObjectId,
3467                                                                                         info->indexkeys[i], false);
3468
3469                                         /* deny if any of column attributes don't match */
3470                                         if (strcmp(p_attname, c_attname) != 0 ||
3471                                                 p_info->indcollation[i] != info->indexcollations[i] ||
3472                                                 p_info->opclass[i] != info->opcintype[i]||
3473                                                 ((p_info->indoption[i] & INDOPTION_DESC) != 0)
3474                                                 != info->reverse_sort[i] ||
3475                                                 ((p_info->indoption[i] & INDOPTION_NULLS_FIRST) != 0)
3476                                                 != info->nulls_first[i])
3477                                                 break;
3478                                 }
3479
3480                                 /* deny this if any difference found */
3481                                 if (i != info->ncolumns)
3482                                         continue;
3483
3484                                 /* check on key expressions  */
3485                                 if ((p_info->expression_str && (info->indexprs != NIL)) ||
3486                                         (p_info->indpred_str && (info->indpred != NIL)))
3487                                 {
3488                                         /* fetch the index of this child */
3489                                         ht_idx = SearchSysCache1(INDEXRELID,
3490                                                                                          ObjectIdGetDatum(info->indexoid));
3491
3492                                         /* check expressions if both expressions are available */
3493                                         if (p_info->expression_str &&
3494                                                 !heap_attisnull(ht_idx, Anum_pg_index_indexprs, NULL))
3495                                         {
3496                                                 Datum       exprsDatum;
3497                                                 bool        isnull;
3498                                                 Datum       result;
3499
3500                                                 /*
3501                                                  * to change the expression's parameter of child's
3502                                                  * index to strings
3503                                                  */
3504                                                 exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
3505                                                                                                          Anum_pg_index_indexprs,
3506                                                                                                          &isnull);
3507
3508                                                 result = DirectFunctionCall2(pg_get_expr,
3509                                                                                                          exprsDatum,
3510                                                                                                          ObjectIdGetDatum(
3511                                                                                                                  relationObjectId));
3512
3513                                                 /* deny if expressions don't match */
3514                                                 if (strcmp(p_info->expression_str,
3515                                                                    text_to_cstring(DatumGetTextP(result))) != 0)
3516                                                 {
3517                                                         /* Clean up */
3518                                                         ReleaseSysCache(ht_idx);
3519                                                         continue;
3520                                                 }
3521                                         }
3522
3523                                         /* compare index predicates  */
3524                                         if (p_info->indpred_str &&
3525                                                 !heap_attisnull(ht_idx, Anum_pg_index_indpred, NULL))
3526                                         {
3527                                                 Datum       predDatum;
3528                                                 bool        isnull;
3529                                                 Datum       result;
3530
3531                                                 predDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
3532                                                                                                          Anum_pg_index_indpred,
3533                                                                                                          &isnull);
3534
3535                                                 result = DirectFunctionCall2(pg_get_expr,
3536                                                                                                          predDatum,
3537                                                                                                          ObjectIdGetDatum(
3538                                                                                                                  relationObjectId));
3539
3540                                                 if (strcmp(p_info->indpred_str,
3541                                                                    text_to_cstring(DatumGetTextP(result))) != 0)
3542                                                 {
3543                                                         /* Clean up */
3544                                                         ReleaseSysCache(ht_idx);
3545                                                         continue;
3546                                                 }
3547                                         }
3548
3549                                         /* Clean up */
3550                                         ReleaseSysCache(ht_idx);
3551                                 }
3552                                 else if (p_info->expression_str || (info->indexprs != NIL))
3553                                         continue;
3554                                 else if (p_info->indpred_str || (info->indpred != NIL))
3555                                         continue;
3556
3557                                 use_index = true;
3558
3559                                 /* to log the candidate of index */
3560                                 if (debug_level > 0)
3561                                 {
3562                                         appendStringInfoCharMacro(&buf, ' ');
3563                                         quote_value(&buf, indexname);
3564                                 }
3565
3566                                 break;
3567                         }
3568                 }
3569
3570                 if (!use_index)
3571                         rel->indexlist = list_delete_cell(rel->indexlist, cell, prev);
3572                 else
3573                         prev = cell;
3574
3575                 pfree(indexname);
3576         }
3577
3578         if (debug_level == 1)
3579         {
3580                 StringInfoData  rel_buf;
3581                 char *disprelname = "";
3582
3583                 /*
3584                  * If this hint targetted the parent, use the real name of this
3585                  * child. Otherwise use hint specification.
3586                  */
3587                 if (using_parent_hint)
3588                         disprelname = get_rel_name(rte->relid);
3589                 else
3590                         disprelname = hint->relname;
3591
3592
3593                 initStringInfo(&rel_buf);
3594                 quote_value(&rel_buf, disprelname);
3595
3596                 ereport(pg_hint_plan_debug_message_level,
3597                                 (errmsg("available indexes for %s(%s):%s",
3598                                          hint->base.keyword,
3599                                          rel_buf.data,
3600                                          buf.data)));
3601                 pfree(buf.data);
3602                 pfree(rel_buf.data);
3603         }
3604 }
3605
3606 /*
3607  * Return information of index definition.
3608  */
3609 static ParentIndexInfo *
3610 get_parent_index_info(Oid indexoid, Oid relid)
3611 {
3612         ParentIndexInfo *p_info = palloc(sizeof(ParentIndexInfo));
3613         Relation            indexRelation;
3614         Form_pg_index   index;
3615         char               *attname;
3616         int                             i;
3617
3618         indexRelation = index_open(indexoid, RowExclusiveLock);
3619
3620         index = indexRelation->rd_index;
3621
3622         p_info->indisunique = index->indisunique;
3623         p_info->method = indexRelation->rd_rel->relam;
3624
3625         p_info->column_names = NIL;
3626         p_info->indcollation = (Oid *) palloc(sizeof(Oid) * index->indnatts);
3627         p_info->opclass = (Oid *) palloc(sizeof(Oid) * index->indnatts);
3628         p_info->indoption = (int16 *) palloc(sizeof(Oid) * index->indnatts);
3629
3630         /*
3631          * Collect relation attribute names of index columns for index
3632          * identification, not index attribute names. NULL means expression index
3633          * columns.
3634          */
3635         for (i = 0; i < index->indnatts; i++)
3636         {
3637                 attname = get_attname(relid, index->indkey.values[i], true);
3638                 p_info->column_names = lappend(p_info->column_names, attname);
3639
3640                 p_info->indcollation[i] = indexRelation->rd_indcollation[i];
3641                 p_info->opclass[i] = indexRelation->rd_opcintype[i];
3642                 p_info->indoption[i] = indexRelation->rd_indoption[i];
3643         }
3644
3645         /*
3646          * to check to match the expression's parameter of index with child indexes
3647          */
3648         p_info->expression_str = NULL;
3649         if(!heap_attisnull(indexRelation->rd_indextuple, Anum_pg_index_indexprs,
3650                                            NULL))
3651         {
3652                 Datum       exprsDatum;
3653                 bool            isnull;
3654                 Datum           result;
3655
3656                 exprsDatum = SysCacheGetAttr(INDEXRELID, indexRelation->rd_indextuple,
3657                                                                          Anum_pg_index_indexprs, &isnull);
3658
3659                 result = DirectFunctionCall2(pg_get_expr,
3660                                                                          exprsDatum,
3661                                                                          ObjectIdGetDatum(relid));
3662
3663                 p_info->expression_str = text_to_cstring(DatumGetTextP(result));
3664         }
3665
3666         /*
3667          * to check to match the predicate's parameter of index with child indexes
3668          */
3669         p_info->indpred_str = NULL;
3670         if(!heap_attisnull(indexRelation->rd_indextuple, Anum_pg_index_indpred,
3671                                            NULL))
3672         {
3673                 Datum       predDatum;
3674                 bool            isnull;
3675                 Datum           result;
3676
3677                 predDatum = SysCacheGetAttr(INDEXRELID, indexRelation->rd_indextuple,
3678                                                                          Anum_pg_index_indpred, &isnull);
3679
3680                 result = DirectFunctionCall2(pg_get_expr,
3681                                                                          predDatum,
3682                                                                          ObjectIdGetDatum(relid));
3683
3684                 p_info->indpred_str = text_to_cstring(DatumGetTextP(result));
3685         }
3686
3687         index_close(indexRelation, NoLock);
3688
3689         return p_info;
3690 }
3691
3692 /*
3693  * cancel hint enforcement
3694  */
3695 static void
3696 reset_hint_enforcement()
3697 {
3698         setup_scan_method_enforcement(NULL, current_hint_state);
3699         setup_parallel_plan_enforcement(NULL, current_hint_state);
3700 }
3701
3702 /*
3703  * Set planner guc parameters according to corresponding scan hints.  Returns
3704  * bitmap of HintTypeBitmap. If shint or phint is not NULL, set used hint
3705  * there respectively.
3706  */
3707 static int
3708 setup_hint_enforcement(PlannerInfo *root, RelOptInfo *rel,
3709                                            ScanMethodHint **rshint, ParallelHint **rphint)
3710 {
3711         Index   new_parent_relid = 0;
3712         ListCell *l;
3713         ScanMethodHint *shint = NULL;
3714         ParallelHint   *phint = NULL;
3715         bool                    inhparent = root->simple_rte_array[rel->relid]->inh;
3716         Oid             relationObjectId = root->simple_rte_array[rel->relid]->relid;
3717         int                             ret = 0;
3718
3719         /* reset returns if requested  */
3720         if (rshint != NULL) *rshint = NULL;
3721         if (rphint != NULL) *rphint = NULL;
3722
3723         /*
3724          * We could register the parent relation of the following children here
3725          * when inhparent == true but inheritnce planner doesn't call this function
3726          * for parents. Since we cannot distinguish who called this function we
3727          * cannot do other than always seeking the parent regardless of who called
3728          * this function.
3729          */
3730         if (inhparent)
3731         {
3732                 /* set up only parallel hints for parent relation */
3733                 phint = find_parallel_hint(root, rel->relid);
3734                 if (phint)
3735                 {
3736                         setup_parallel_plan_enforcement(phint, current_hint_state);
3737                         if (rphint) *rphint = phint;
3738                         ret |= HINT_BM_PARALLEL;
3739                         return ret;
3740                 }
3741
3742                 if (debug_level > 1)
3743                         ereport(pg_hint_plan_debug_message_level,
3744                                         (errhidestmt(true),
3745                                          errmsg ("pg_hint_plan%s: setup_hint_enforcement"
3746                                                          " skipping inh parent: relation=%u(%s), inhparent=%d,"
3747                                                          " current_hint_state=%p, hint_inhibit_level=%d",
3748                                                          qnostr, relationObjectId,
3749                                                          get_rel_name(relationObjectId),
3750                                                          inhparent, current_hint_state, hint_inhibit_level)));
3751                 return 0;
3752         }
3753
3754         /*
3755          * Forget about the parent of another subquery, but don't forget if the
3756          * inhTargetkind of the root is not INHKIND_NONE, which signals the root
3757          * contains only appendrel members. See inheritance_planner for details.
3758          *
3759          * (PG12.0) 428b260f87 added one more planning cycle for updates on
3760          * partitioned tables and hints set up in the cycle are overriden by the
3761          * second cycle. Since I didn't find no apparent distinction between the
3762          * PlannerRoot of the cycle and that of ordinary CMD_SELECT, pg_hint_plan
3763          * accepts both cycles and the later one wins. In the second cycle root
3764          * doesn't have inheritance information at all so use the parent_relid set
3765          * in the first cycle.
3766          */
3767         if (root->inhTargetKind == INHKIND_NONE)
3768         {
3769                 if (root != current_hint_state->current_root)
3770                         current_hint_state->parent_relid = 0;
3771
3772                 /* Find the parent for this relation other than the registered parent */
3773                 foreach (l, root->append_rel_list)
3774                 {
3775                         AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
3776
3777                         if (appinfo->child_relid == rel->relid)
3778                         {
3779                                 if (current_hint_state->parent_relid != appinfo->parent_relid)
3780                                 {
3781                                         new_parent_relid = appinfo->parent_relid;
3782                                         current_hint_state->current_root = root;
3783                                 }
3784                                 break;
3785                         }
3786                 }
3787
3788                 if (!l)
3789                 {
3790                         /*
3791                          * This relation doesn't have a parent. Cancel
3792                          * current_hint_state.
3793                          */
3794                         current_hint_state->parent_relid = 0;
3795                         current_hint_state->parent_scan_hint = NULL;
3796                         current_hint_state->parent_parallel_hint = NULL;
3797                 }
3798         }
3799
3800         if (new_parent_relid > 0)
3801         {
3802                 /*
3803                  * Here we found a new parent for the current relation. Scan continues
3804                  * hint to other childrens of this parent so remember it to avoid
3805                  * redundant setup cost.
3806                  */
3807                 current_hint_state->parent_relid = new_parent_relid;
3808
3809                 /* Find hints for the parent */
3810                 current_hint_state->parent_scan_hint =
3811                         find_scan_hint(root, current_hint_state->parent_relid);
3812
3813                 current_hint_state->parent_parallel_hint =
3814                         find_parallel_hint(root, current_hint_state->parent_relid);
3815
3816                 /*
3817                  * If hint is found for the parent, apply it for this child instead
3818                  * of its own.
3819                  */
3820                 if (current_hint_state->parent_scan_hint)
3821                 {
3822                         ScanMethodHint * pshint = current_hint_state->parent_scan_hint;
3823
3824                         pshint->base.state = HINT_STATE_USED;
3825
3826                         /* Apply index mask in the same manner to the parent. */
3827                         if (pshint->indexnames)
3828                         {
3829                                 Oid                     parentrel_oid;
3830                                 Relation        parent_rel;
3831
3832                                 parentrel_oid =
3833                                         root->simple_rte_array[current_hint_state->parent_relid]->relid;
3834                                 parent_rel = heap_open(parentrel_oid, NoLock);
3835
3836                                 /* Search the parent relation for indexes match the hint spec */
3837                                 foreach(l, RelationGetIndexList(parent_rel))
3838                                 {
3839                                         Oid         indexoid = lfirst_oid(l);
3840                                         char       *indexname = get_rel_name(indexoid);
3841                                         ListCell   *lc;
3842                                         ParentIndexInfo *parent_index_info;
3843
3844                                         foreach(lc, pshint->indexnames)
3845                                         {
3846                                                 if (RelnameCmp(&indexname, &lfirst(lc)) == 0)
3847                                                         break;
3848                                         }
3849                                         if (!lc)
3850                                                 continue;
3851
3852                                         parent_index_info =
3853                                                 get_parent_index_info(indexoid, parentrel_oid);
3854                                         current_hint_state->parent_index_infos =
3855                                                 lappend(current_hint_state->parent_index_infos,
3856                                                                 parent_index_info);
3857                                 }
3858                                 heap_close(parent_rel, NoLock);
3859                         }
3860                 }
3861         }
3862
3863         shint = find_scan_hint(root, rel->relid);
3864         if (!shint)
3865                 shint = current_hint_state->parent_scan_hint;
3866
3867         if (shint)
3868         {
3869                 bool using_parent_hint =
3870                         (shint == current_hint_state->parent_scan_hint);
3871
3872                 ret |= HINT_BM_SCAN_METHOD;
3873
3874                 /* Setup scan enforcement environment */
3875                 setup_scan_method_enforcement(shint, current_hint_state);
3876
3877                 /* restrict unwanted inexes */
3878                 restrict_indexes(root, shint, rel, using_parent_hint);
3879
3880                 if (debug_level > 1)
3881                 {
3882                         char *additional_message = "";
3883
3884                         if (shint == current_hint_state->parent_scan_hint)
3885                                 additional_message = " by parent hint";
3886
3887                         ereport(pg_hint_plan_debug_message_level,
3888                                         (errhidestmt(true),
3889                                          errmsg ("pg_hint_plan%s: setup_hint_enforcement"
3890                                                          " index deletion%s:"
3891                                                          " relation=%u(%s), inhparent=%d, "
3892                                                          "current_hint_state=%p,"
3893                                                          " hint_inhibit_level=%d, scanmask=0x%x",
3894                                                          qnostr, additional_message,
3895                                                          relationObjectId,
3896                                                          get_rel_name(relationObjectId),
3897                                                          inhparent, current_hint_state,
3898                                                          hint_inhibit_level,
3899                                                          shint->enforce_mask)));
3900                 }
3901         }
3902
3903         /* Do the same for parallel plan enforcement */
3904         phint = find_parallel_hint(root, rel->relid);
3905         if (!phint)
3906                 phint = current_hint_state->parent_parallel_hint;
3907
3908         setup_parallel_plan_enforcement(phint, current_hint_state);
3909
3910         if (phint)
3911                 ret |= HINT_BM_PARALLEL;
3912
3913         /* Nothing to apply. Reset the scan mask to intial state */
3914         if (!shint && ! phint)
3915         {
3916                 if (debug_level > 1)
3917                         ereport(pg_hint_plan_debug_message_level,
3918                                         (errhidestmt (true),
3919                                          errmsg ("pg_hint_plan%s: setup_hint_enforcement"
3920                                                          " no hint applied:"
3921                                                          " relation=%u(%s), inhparent=%d, current_hint=%p,"
3922                                                          " hint_inhibit_level=%d, scanmask=0x%x",
3923                                                          qnostr, relationObjectId,
3924                                                          get_rel_name(relationObjectId),
3925                                                          inhparent, current_hint_state, hint_inhibit_level,
3926                                                          current_hint_state->init_scan_mask)));
3927
3928                 setup_scan_method_enforcement(NULL,     current_hint_state);
3929
3930                 return ret;
3931         }
3932
3933         if (rshint != NULL) *rshint = shint;
3934         if (rphint != NULL) *rphint = phint;
3935
3936         return ret;
3937 }
3938
3939 /*
3940  * Return index of relation which matches given aliasname, or 0 if not found.
3941  * If same aliasname was used multiple times in a query, return -1.
3942  */
3943 static int
3944 find_relid_aliasname(PlannerInfo *root, char *aliasname, List *initial_rels,
3945                                          const char *str)
3946 {
3947         int             i;
3948         Index   found = 0;
3949
3950         for (i = 1; i < root->simple_rel_array_size; i++)
3951         {
3952                 ListCell   *l;
3953
3954                 if (root->simple_rel_array[i] == NULL)
3955                         continue;
3956
3957                 Assert(i == root->simple_rel_array[i]->relid);
3958
3959                 if (RelnameCmp(&aliasname,
3960                                            &root->simple_rte_array[i]->eref->aliasname) != 0)
3961                         continue;
3962
3963                 foreach(l, initial_rels)
3964                 {
3965                         RelOptInfo *rel = (RelOptInfo *) lfirst(l);
3966
3967                         if (rel->reloptkind == RELOPT_BASEREL)
3968                         {
3969                                 if (rel->relid != i)
3970                                         continue;
3971                         }
3972                         else
3973                         {
3974                                 Assert(rel->reloptkind == RELOPT_JOINREL);
3975
3976                                 if (!bms_is_member(i, rel->relids))
3977                                         continue;
3978                         }
3979
3980                         if (found != 0)
3981                         {
3982                                 hint_ereport(str,
3983                                                          ("Relation name \"%s\" is ambiguous.",
3984                                                           aliasname));
3985                                 return -1;
3986                         }
3987
3988                         found = i;
3989                         break;
3990                 }
3991
3992         }
3993
3994         return found;
3995 }
3996
3997 /*
3998  * Return join hint which matches given joinrelids.
3999  */
4000 static JoinMethodHint *
4001 find_join_hint(Relids joinrelids)
4002 {
4003         List       *join_hint;
4004         ListCell   *l;
4005
4006         join_hint = current_hint_state->join_hint_level[bms_num_members(joinrelids)];
4007
4008         foreach(l, join_hint)
4009         {
4010                 JoinMethodHint *hint = (JoinMethodHint *) lfirst(l);
4011
4012                 if (bms_equal(joinrelids, hint->joinrelids))
4013                         return hint;
4014         }
4015
4016         return NULL;
4017 }
4018
4019 static Relids
4020 OuterInnerJoinCreate(OuterInnerRels *outer_inner, LeadingHint *leading_hint,
4021         PlannerInfo *root, List *initial_rels, HintState *hstate, int nbaserel)
4022 {
4023         OuterInnerRels *outer_rels;
4024         OuterInnerRels *inner_rels;
4025         Relids                  outer_relids;
4026         Relids                  inner_relids;
4027         Relids                  join_relids;
4028         JoinMethodHint *hint;
4029
4030         if (outer_inner->relation != NULL)
4031         {
4032                 return bms_make_singleton(
4033                                         find_relid_aliasname(root, outer_inner->relation,
4034                                                                                  initial_rels,
4035                                                                                  leading_hint->base.hint_str));
4036         }
4037
4038         outer_rels = lfirst(outer_inner->outer_inner_pair->head);
4039         inner_rels = lfirst(outer_inner->outer_inner_pair->tail);
4040
4041         outer_relids = OuterInnerJoinCreate(outer_rels,
4042                                                                                 leading_hint,
4043                                                                                 root,
4044                                                                                 initial_rels,
4045                                                                                 hstate,
4046                                                                                 nbaserel);
4047         inner_relids = OuterInnerJoinCreate(inner_rels,
4048                                                                                 leading_hint,
4049                                                                                 root,
4050                                                                                 initial_rels,
4051                                                                                 hstate,
4052                                                                                 nbaserel);
4053
4054         join_relids = bms_add_members(outer_relids, inner_relids);
4055
4056         if (bms_num_members(join_relids) > nbaserel)
4057                 return join_relids;
4058
4059         /*
4060          * If we don't have join method hint, create new one for the
4061          * join combination with all join methods are enabled.
4062          */
4063         hint = find_join_hint(join_relids);
4064         if (hint == NULL)
4065         {
4066                 /*
4067                  * Here relnames is not set, since Relids bitmap is sufficient to
4068                  * control paths of this query afterward.
4069                  */
4070                 hint = (JoinMethodHint *) JoinMethodHintCreate(
4071                                         leading_hint->base.hint_str,
4072                                         HINT_LEADING,
4073                                         HINT_KEYWORD_LEADING);
4074                 hint->base.state = HINT_STATE_USED;
4075                 hint->nrels = bms_num_members(join_relids);
4076                 hint->enforce_mask = ENABLE_ALL_JOIN;
4077                 hint->joinrelids = bms_copy(join_relids);
4078                 hint->inner_nrels = bms_num_members(inner_relids);
4079                 hint->inner_joinrelids = bms_copy(inner_relids);
4080
4081                 hstate->join_hint_level[hint->nrels] =
4082                         lappend(hstate->join_hint_level[hint->nrels], hint);
4083         }
4084         else
4085         {
4086                 hint->inner_nrels = bms_num_members(inner_relids);
4087                 hint->inner_joinrelids = bms_copy(inner_relids);
4088         }
4089
4090         return join_relids;
4091 }
4092
4093 static Relids
4094 create_bms_of_relids(Hint *base, PlannerInfo *root, List *initial_rels,
4095                 int nrels, char **relnames)
4096 {
4097         int             relid;
4098         Relids  relids = NULL;
4099         int             j;
4100         char   *relname;
4101
4102         for (j = 0; j < nrels; j++)
4103         {
4104                 relname = relnames[j];
4105
4106                 relid = find_relid_aliasname(root, relname, initial_rels,
4107                                                                          base->hint_str);
4108
4109                 if (relid == -1)
4110                         base->state = HINT_STATE_ERROR;
4111
4112                 /*
4113                  * the aliasname is not found(relid == 0) or same aliasname was used
4114                  * multiple times in a query(relid == -1)
4115                  */
4116                 if (relid <= 0)
4117                 {
4118                         relids = NULL;
4119                         break;
4120                 }
4121                 if (bms_is_member(relid, relids))
4122                 {
4123                         hint_ereport(base->hint_str,
4124                                                  ("Relation name \"%s\" is duplicated.", relname));
4125                         base->state = HINT_STATE_ERROR;
4126                         break;
4127                 }
4128
4129                 relids = bms_add_member(relids, relid);
4130         }
4131         return relids;
4132 }
4133 /*
4134  * Transform join method hint into handy form.
4135  *
4136  *   - create bitmap of relids from alias names, to make it easier to check
4137  *     whether a join path matches a join method hint.
4138  *   - add join method hints which are necessary to enforce join order
4139  *     specified by Leading hint
4140  */
4141 static bool
4142 transform_join_hints(HintState *hstate, PlannerInfo *root, int nbaserel,
4143                 List *initial_rels, JoinMethodHint **join_method_hints)
4144 {
4145         int                             i;
4146         int                             relid;
4147         Relids                  joinrelids;
4148         int                             njoinrels;
4149         ListCell           *l;
4150         char               *relname;
4151         LeadingHint        *lhint = NULL;
4152
4153         /*
4154          * Create bitmap of relids from alias names for each join method hint.
4155          * Bitmaps are more handy than strings in join searching.
4156          */
4157         for (i = 0; i < hstate->num_hints[HINT_TYPE_JOIN_METHOD]; i++)
4158         {
4159                 JoinMethodHint *hint = hstate->join_hints[i];
4160
4161                 if (!hint_state_enabled(hint) || hint->nrels > nbaserel)
4162                         continue;
4163
4164                 hint->joinrelids = create_bms_of_relids(&(hint->base), root,
4165                                                                          initial_rels, hint->nrels, hint->relnames);
4166
4167                 if (hint->joinrelids == NULL || hint->base.state == HINT_STATE_ERROR)
4168                         continue;
4169
4170                 hstate->join_hint_level[hint->nrels] =
4171                         lappend(hstate->join_hint_level[hint->nrels], hint);
4172         }
4173
4174         /*
4175          * Create bitmap of relids from alias names for each rows hint.
4176          * Bitmaps are more handy than strings in join searching.
4177          */
4178         for (i = 0; i < hstate->num_hints[HINT_TYPE_ROWS]; i++)
4179         {
4180                 RowsHint *hint = hstate->rows_hints[i];
4181
4182                 if (!hint_state_enabled(hint) || hint->nrels > nbaserel)
4183                         continue;
4184
4185                 hint->joinrelids = create_bms_of_relids(&(hint->base), root,
4186                                                                          initial_rels, hint->nrels, hint->relnames);
4187         }
4188
4189         /* Do nothing if no Leading hint was supplied. */
4190         if (hstate->num_hints[HINT_TYPE_LEADING] == 0)
4191                 return false;
4192
4193         /*
4194          * Decide whether to use Leading hint
4195          */
4196         for (i = 0; i < hstate->num_hints[HINT_TYPE_LEADING]; i++)
4197         {
4198                 LeadingHint        *leading_hint = (LeadingHint *)hstate->leading_hint[i];
4199                 Relids                  relids;
4200
4201                 if (leading_hint->base.state == HINT_STATE_ERROR)
4202                         continue;
4203
4204                 relid = 0;
4205                 relids = NULL;
4206
4207                 foreach(l, leading_hint->relations)
4208                 {
4209                         relname = (char *)lfirst(l);;
4210
4211                         relid = find_relid_aliasname(root, relname, initial_rels,
4212                                                                                  leading_hint->base.hint_str);
4213                         if (relid == -1)
4214                                 leading_hint->base.state = HINT_STATE_ERROR;
4215
4216                         if (relid <= 0)
4217                                 break;
4218
4219                         if (bms_is_member(relid, relids))
4220                         {
4221                                 hint_ereport(leading_hint->base.hint_str,
4222                                                          ("Relation name \"%s\" is duplicated.", relname));
4223                                 leading_hint->base.state = HINT_STATE_ERROR;
4224                                 break;
4225                         }
4226
4227                         relids = bms_add_member(relids, relid);
4228                 }
4229
4230                 if (relid <= 0 || leading_hint->base.state == HINT_STATE_ERROR)
4231                         continue;
4232
4233                 if (lhint != NULL)
4234                 {
4235                         hint_ereport(lhint->base.hint_str,
4236                                  ("Conflict %s hint.", HintTypeName[lhint->base.type]));
4237                         lhint->base.state = HINT_STATE_DUPLICATION;
4238                 }
4239                 leading_hint->base.state = HINT_STATE_USED;
4240                 lhint = leading_hint;
4241         }
4242
4243         /* check to exist Leading hint marked with 'used'. */
4244         if (lhint == NULL)
4245                 return false;
4246
4247         /*
4248          * We need join method hints which fit specified join order in every join
4249          * level.  For example, Leading(A B C) virtually requires following join
4250          * method hints, if no join method hint supplied:
4251          *   - level 1: none
4252          *   - level 2: NestLoop(A B), MergeJoin(A B), HashJoin(A B)
4253          *   - level 3: NestLoop(A B C), MergeJoin(A B C), HashJoin(A B C)
4254          *
4255          * If we already have join method hint which fits specified join order in
4256          * that join level, we leave it as-is and don't add new hints.
4257          */
4258         joinrelids = NULL;
4259         njoinrels = 0;
4260         if (lhint->outer_inner == NULL)
4261         {
4262                 foreach(l, lhint->relations)
4263                 {
4264                         JoinMethodHint *hint;
4265
4266                         relname = (char *)lfirst(l);
4267
4268                         /*
4269                          * Find relid of the relation which has given name.  If we have the
4270                          * name given in Leading hint multiple times in the join, nothing to
4271                          * do.
4272                          */
4273                         relid = find_relid_aliasname(root, relname, initial_rels,
4274                                                                                  hstate->hint_str);
4275
4276                         /* Create bitmap of relids for current join level. */
4277                         joinrelids = bms_add_member(joinrelids, relid);
4278                         njoinrels++;
4279
4280                         /* We never have join method hint for single relation. */
4281                         if (njoinrels < 2)
4282                                 continue;
4283
4284                         /*
4285                          * If we don't have join method hint, create new one for the
4286                          * join combination with all join methods are enabled.
4287                          */
4288                         hint = find_join_hint(joinrelids);
4289                         if (hint == NULL)
4290                         {
4291                                 /*
4292                                  * Here relnames is not set, since Relids bitmap is sufficient
4293                                  * to control paths of this query afterward.
4294                                  */
4295                                 hint = (JoinMethodHint *) JoinMethodHintCreate(
4296                                                                                         lhint->base.hint_str,
4297                                                                                         HINT_LEADING,
4298                                                                                         HINT_KEYWORD_LEADING);
4299                                 hint->base.state = HINT_STATE_USED;
4300                                 hint->nrels = njoinrels;
4301                                 hint->enforce_mask = ENABLE_ALL_JOIN;
4302                                 hint->joinrelids = bms_copy(joinrelids);
4303                         }
4304
4305                         join_method_hints[njoinrels] = hint;
4306
4307                         if (njoinrels >= nbaserel)
4308                                 break;
4309                 }
4310                 bms_free(joinrelids);
4311
4312                 if (njoinrels < 2)
4313                         return false;
4314
4315                 /*
4316                  * Delete all join hints which have different combination from Leading
4317                  * hint.
4318                  */
4319                 for (i = 2; i <= njoinrels; i++)
4320                 {
4321                         list_free(hstate->join_hint_level[i]);
4322
4323                         hstate->join_hint_level[i] = lappend(NIL, join_method_hints[i]);
4324                 }
4325         }
4326         else
4327         {
4328                 joinrelids = OuterInnerJoinCreate(lhint->outer_inner,
4329                                                                                   lhint,
4330                                           root,
4331                                           initial_rels,
4332                                                                                   hstate,
4333                                                                                   nbaserel);
4334
4335                 njoinrels = bms_num_members(joinrelids);
4336                 Assert(njoinrels >= 2);
4337
4338                 /*
4339                  * Delete all join hints which have different combination from Leading
4340                  * hint.
4341                  */
4342                 for (i = 2;i <= njoinrels; i++)
4343                 {
4344                         if (hstate->join_hint_level[i] != NIL)
4345                         {
4346                                 ListCell *prev = NULL;
4347                                 ListCell *next = NULL;
4348                                 for(l = list_head(hstate->join_hint_level[i]); l; l = next)
4349                                 {
4350
4351                                         JoinMethodHint *hint = (JoinMethodHint *)lfirst(l);
4352
4353                                         next = lnext(l);
4354
4355                                         if (hint->inner_nrels == 0 &&
4356                                                 !(bms_intersect(hint->joinrelids, joinrelids) == NULL ||
4357                                                   bms_equal(bms_union(hint->joinrelids, joinrelids),
4358                                                   hint->joinrelids)))
4359                                         {
4360                                                 hstate->join_hint_level[i] =
4361                                                         list_delete_cell(hstate->join_hint_level[i], l,
4362                                                                                          prev);
4363                                         }
4364                                         else
4365                                                 prev = l;
4366                                 }
4367                         }
4368                 }
4369
4370                 bms_free(joinrelids);
4371         }
4372
4373         if (hint_state_enabled(lhint))
4374         {
4375                 set_join_config_options(DISABLE_ALL_JOIN, current_hint_state->context);
4376                 return true;
4377         }
4378         return false;
4379 }
4380
4381 /*
4382  * wrapper of make_join_rel()
4383  *
4384  * call make_join_rel() after changing enable_* parameters according to given
4385  * hints.
4386  */
4387 static RelOptInfo *
4388 make_join_rel_wrapper(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
4389 {
4390         Relids                  joinrelids;
4391         JoinMethodHint *hint;
4392         RelOptInfo         *rel;
4393         int                             save_nestlevel;
4394
4395         joinrelids = bms_union(rel1->relids, rel2->relids);
4396         hint = find_join_hint(joinrelids);
4397         bms_free(joinrelids);
4398
4399         if (!hint)
4400                 return pg_hint_plan_make_join_rel(root, rel1, rel2);
4401
4402         if (hint->inner_nrels == 0)
4403         {
4404                 save_nestlevel = NewGUCNestLevel();
4405
4406                 set_join_config_options(hint->enforce_mask,
4407                                                                 current_hint_state->context);
4408
4409                 rel = pg_hint_plan_make_join_rel(root, rel1, rel2);
4410                 hint->base.state = HINT_STATE_USED;
4411
4412                 /*
4413                  * Restore the GUC variables we set above.
4414                  */
4415                 AtEOXact_GUC(true, save_nestlevel);
4416         }
4417         else
4418                 rel = pg_hint_plan_make_join_rel(root, rel1, rel2);
4419
4420         return rel;
4421 }
4422
4423 /*
4424  * TODO : comment
4425  */
4426 static void
4427 add_paths_to_joinrel_wrapper(PlannerInfo *root,
4428                                                          RelOptInfo *joinrel,
4429                                                          RelOptInfo *outerrel,
4430                                                          RelOptInfo *innerrel,
4431                                                          JoinType jointype,
4432                                                          SpecialJoinInfo *sjinfo,
4433                                                          List *restrictlist)
4434 {
4435         Relids                  joinrelids;
4436         JoinMethodHint *join_hint;
4437         int                             save_nestlevel;
4438
4439         joinrelids = bms_union(outerrel->relids, innerrel->relids);
4440         join_hint = find_join_hint(joinrelids);
4441         bms_free(joinrelids);
4442
4443         if (join_hint && join_hint->inner_nrels != 0)
4444         {
4445                 save_nestlevel = NewGUCNestLevel();
4446
4447                 if (bms_equal(join_hint->inner_joinrelids, innerrel->relids))
4448                 {
4449
4450                         set_join_config_options(join_hint->enforce_mask,
4451                                                                         current_hint_state->context);
4452
4453                         add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
4454                                                                  sjinfo, restrictlist);
4455                         join_hint->base.state = HINT_STATE_USED;
4456                 }
4457                 else
4458                 {
4459                         set_join_config_options(DISABLE_ALL_JOIN,
4460                                                                         current_hint_state->context);
4461                         add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
4462                                                                  sjinfo, restrictlist);
4463                 }
4464
4465                 /*
4466                  * Restore the GUC variables we set above.
4467                  */
4468                 AtEOXact_GUC(true, save_nestlevel);
4469         }
4470         else
4471                 add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
4472                                                          sjinfo, restrictlist);
4473 }
4474
4475 static int
4476 get_num_baserels(List *initial_rels)
4477 {
4478         int                     nbaserel = 0;
4479         ListCell   *l;
4480
4481         foreach(l, initial_rels)
4482         {
4483                 RelOptInfo *rel = (RelOptInfo *) lfirst(l);
4484
4485                 if (rel->reloptkind == RELOPT_BASEREL)
4486                         nbaserel++;
4487                 else if (rel->reloptkind ==RELOPT_JOINREL)
4488                         nbaserel+= bms_num_members(rel->relids);
4489                 else
4490                 {
4491                         /* other values not expected here */
4492                         elog(ERROR, "unrecognized reloptkind type: %d", rel->reloptkind);
4493                 }
4494         }
4495
4496         return nbaserel;
4497 }
4498
4499 static RelOptInfo *
4500 pg_hint_plan_join_search(PlannerInfo *root, int levels_needed,
4501                                                  List *initial_rels)
4502 {
4503         JoinMethodHint    **join_method_hints;
4504         int                                     nbaserel;
4505         RelOptInfo                 *rel;
4506         int                                     i;
4507         bool                            leading_hint_enable;
4508
4509         /*
4510          * Use standard planner (or geqo planner) if pg_hint_plan is disabled or no
4511          * valid hint is supplied or current nesting depth is nesting depth of SPI
4512          * calls.
4513          */
4514         if (!current_hint_state || hint_inhibit_level > 0)
4515         {
4516                 if (prev_join_search)
4517                         return (*prev_join_search) (root, levels_needed, initial_rels);
4518                 else if (enable_geqo && levels_needed >= geqo_threshold)
4519                         return geqo(root, levels_needed, initial_rels);
4520                 else
4521                         return standard_join_search(root, levels_needed, initial_rels);
4522         }
4523
4524         /*
4525          * In the case using GEQO, only scan method hints and Set hints have
4526          * effect.  Join method and join order is not controllable by hints.
4527          */
4528         if (enable_geqo && levels_needed >= geqo_threshold)
4529                 return geqo(root, levels_needed, initial_rels);
4530
4531         nbaserel = get_num_baserels(initial_rels);
4532         current_hint_state->join_hint_level =
4533                 palloc0(sizeof(List *) * (nbaserel + 1));
4534         join_method_hints = palloc0(sizeof(JoinMethodHint *) * (nbaserel + 1));
4535
4536         leading_hint_enable = transform_join_hints(current_hint_state,
4537                                                                                            root, nbaserel,
4538                                                                                            initial_rels, join_method_hints);
4539
4540         rel = pg_hint_plan_standard_join_search(root, levels_needed, initial_rels);
4541
4542         /*
4543          * Adjust number of parallel workers of the result rel to the largest
4544          * number of the component paths.
4545          */
4546         if (current_hint_state->num_hints[HINT_TYPE_PARALLEL] > 0)
4547         {
4548                 ListCell   *lc;
4549                 int             nworkers = 0;
4550
4551                 foreach (lc, initial_rels)
4552                 {
4553                         ListCell *lcp;
4554                         RelOptInfo *rel = (RelOptInfo *) lfirst(lc);
4555
4556                         foreach (lcp, rel->partial_pathlist)
4557                         {
4558                                 Path *path = (Path *) lfirst(lcp);
4559
4560                                 if (nworkers < path-> parallel_workers)
4561                                         nworkers = path-> parallel_workers;
4562                         }
4563                 }
4564
4565                 foreach (lc, rel->partial_pathlist)
4566                 {
4567                         Path *path = (Path *) lfirst(lc);
4568
4569                         if (path->parallel_safe && path->parallel_workers < nworkers)
4570                                 path->parallel_workers = nworkers;
4571                 }
4572         }
4573
4574         for (i = 2; i <= nbaserel; i++)
4575         {
4576                 list_free(current_hint_state->join_hint_level[i]);
4577
4578                 /* free Leading hint only */
4579                 if (join_method_hints[i] != NULL &&
4580                         join_method_hints[i]->enforce_mask == ENABLE_ALL_JOIN)
4581                         JoinMethodHintDelete(join_method_hints[i]);
4582         }
4583         pfree(current_hint_state->join_hint_level);
4584         pfree(join_method_hints);
4585
4586         if (leading_hint_enable)
4587                 set_join_config_options(current_hint_state->init_join_mask,
4588                                                                 current_hint_state->context);
4589
4590         return rel;
4591 }
4592
4593 /*
4594  * Force number of wokers if instructed by hint
4595  */
4596 void
4597 pg_hint_plan_set_rel_pathlist(PlannerInfo * root, RelOptInfo *rel,
4598                                                           Index rti, RangeTblEntry *rte)
4599 {
4600         ParallelHint   *phint;
4601         ListCell           *l;
4602         int                             found_hints;
4603
4604         /* call the previous hook */
4605         if (prev_set_rel_pathlist)
4606                 prev_set_rel_pathlist(root, rel, rti, rte);
4607
4608         /* Nothing to do if no hint available */
4609         if (current_hint_state == NULL)
4610                 return;
4611
4612         /* Don't touch dummy rels. */
4613         if (IS_DUMMY_REL(rel))
4614                 return;
4615
4616         /*
4617          * We can accept only plain relations, foreign tables and table saples are
4618          * also unacceptable. See set_rel_pathlist.
4619          */
4620         if ((rel->rtekind != RTE_RELATION &&
4621                  rel->rtekind != RTE_SUBQUERY)||
4622                 rte->relkind == RELKIND_FOREIGN_TABLE ||
4623                 rte->tablesample != NULL)
4624                 return;
4625
4626         /*
4627          * Even though UNION ALL node doesn't have particular name so usually it is
4628          * unhintable, turn on parallel when it contains parallel nodes.
4629          */
4630         if (rel->rtekind == RTE_SUBQUERY)
4631         {
4632                 ListCell *lc;
4633                 bool    inhibit_nonparallel = false;
4634
4635                 if (rel->partial_pathlist == NIL)
4636                         return;
4637
4638                 foreach(lc, rel->partial_pathlist)
4639                 {
4640                         ListCell *lcp;
4641                         AppendPath *apath = (AppendPath *) lfirst(lc);
4642                         int             parallel_workers = 0;
4643
4644                         if (!IsA(apath, AppendPath))
4645                                 continue;
4646
4647                         foreach (lcp, apath->subpaths)
4648                         {
4649                                 Path *spath = (Path *) lfirst(lcp);
4650
4651                                 if (spath->parallel_aware &&
4652                                         parallel_workers < spath->parallel_workers)
4653                                         parallel_workers = spath->parallel_workers;
4654                         }
4655
4656                         apath->path.parallel_workers = parallel_workers;
4657                         inhibit_nonparallel = true;
4658                 }
4659
4660                 if (inhibit_nonparallel)
4661                 {
4662                         ListCell *lc;
4663
4664                         foreach(lc, rel->pathlist)
4665                         {
4666                                 Path *path = (Path *) lfirst(lc);
4667
4668                                 if (path->startup_cost < disable_cost)
4669                                 {
4670                                         path->startup_cost += disable_cost;
4671                                         path->total_cost += disable_cost;
4672                                 }
4673                         }
4674                 }
4675
4676                 return;
4677         }
4678
4679         /* We cannot handle if this requires an outer */
4680         if (rel->lateral_relids)
4681                 return;
4682
4683         /* Return if this relation gets no enfocement */
4684         if ((found_hints = setup_hint_enforcement(root, rel, NULL, &phint)) == 0)
4685                 return;
4686
4687         /* Here, we regenerate paths with the current hint restriction */
4688         if (found_hints & HINT_BM_SCAN_METHOD || found_hints & HINT_BM_PARALLEL)
4689         {
4690                 /*
4691                  * When hint is specified on non-parent relations, discard existing
4692                  * paths and regenerate based on the hint considered. Otherwise we
4693                  * already have hinted childx paths then just adjust the number of
4694                  * planned number of workers.
4695                  */
4696                 if (root->simple_rte_array[rel->relid]->inh)
4697                 {
4698                         /* enforce number of workers if requested */
4699                         if (phint && phint->force_parallel)
4700                         {
4701                                 if (phint->nworkers == 0)
4702                                 {
4703                                         list_free_deep(rel->partial_pathlist);
4704                                         rel->partial_pathlist = NIL;
4705                                 }
4706                                 else
4707                                 {
4708                                         /* prioritize partial paths */
4709                                         foreach (l, rel->partial_pathlist)
4710                                         {
4711                                                 Path *ppath = (Path *) lfirst(l);
4712
4713                                                 if (ppath->parallel_safe)
4714                                                 {
4715                                                         ppath->parallel_workers = phint->nworkers;
4716                                                         ppath->startup_cost = 0;
4717                                                         ppath->total_cost = 0;
4718                                                 }
4719                                         }
4720
4721                                         /* disable non-partial paths */
4722                                         foreach (l, rel->pathlist)
4723                                         {
4724                                                 Path *ppath = (Path *) lfirst(l);
4725
4726                                                 if (ppath->startup_cost < disable_cost)
4727                                                 {
4728                                                         ppath->startup_cost += disable_cost;
4729                                                         ppath->total_cost += disable_cost;
4730                                                 }
4731                                         }
4732                                 }
4733                         }
4734                 }
4735                 else
4736                 {
4737                         /* Just discard all the paths considered so far */
4738                         list_free_deep(rel->pathlist);
4739                         rel->pathlist = NIL;
4740                         list_free_deep(rel->partial_pathlist);
4741                         rel->partial_pathlist = NIL;
4742
4743                         /* Regenerate paths with the current enforcement */
4744                         set_plain_rel_pathlist(root, rel, rte);
4745
4746                         /* Additional work to enforce parallel query execution */
4747                         if (phint && phint->nworkers > 0)
4748                         {
4749                                 /*
4750                                  * For Parallel Append to be planned properly, we shouldn't set
4751                                  * the costs of non-partial paths to disable-value.  Lower the
4752                                  * priority of non-parallel paths by setting partial path costs
4753                                  * to 0 instead.
4754                                  */
4755                                 foreach (l, rel->partial_pathlist)
4756                                 {
4757                                         Path *path = (Path *) lfirst(l);
4758
4759                                         path->startup_cost = 0;
4760                                         path->total_cost = 0;
4761                                 }
4762
4763                                 /* enforce number of workers if requested */
4764                                 if (phint->force_parallel)
4765                                 {
4766                                         foreach (l, rel->partial_pathlist)
4767                                         {
4768                                                 Path *ppath = (Path *) lfirst(l);
4769
4770                                                 if (ppath->parallel_safe)
4771                                                         ppath->parallel_workers = phint->nworkers;
4772                                         }
4773                                 }
4774
4775                                 /* Generate gather paths */
4776                                 if (rel->reloptkind == RELOPT_BASEREL &&
4777                                         bms_membership(root->all_baserels) != BMS_SINGLETON)
4778                                         generate_gather_paths(root, rel, false);
4779                         }
4780                 }
4781         }
4782
4783         reset_hint_enforcement();
4784 }
4785
4786 /*
4787  * set_rel_pathlist
4788  *        Build access paths for a base relation
4789  *
4790  * This function was copied and edited from set_rel_pathlist() in
4791  * src/backend/optimizer/path/allpaths.c in order not to copy other static
4792  * functions not required here.
4793  */
4794 static void
4795 set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
4796                                  Index rti, RangeTblEntry *rte)
4797 {
4798         if (IS_DUMMY_REL(rel))
4799         {
4800                 /* We already proved the relation empty, so nothing more to do */
4801         }
4802         else if (rte->inh)
4803         {
4804                 /* It's an "append relation", process accordingly */
4805                 set_append_rel_pathlist(root, rel, rti, rte);
4806         }
4807         else
4808         {
4809                 if (rel->rtekind == RTE_RELATION)
4810                 {
4811                         if (rte->relkind == RELKIND_RELATION)
4812                         {
4813                                 if(rte->tablesample != NULL)
4814                                         elog(ERROR, "sampled relation is not supported");
4815
4816                                 /* Plain relation */
4817                                 set_plain_rel_pathlist(root, rel, rte);
4818                         }
4819                         else
4820                                 elog(ERROR, "unexpected relkind: %c", rte->relkind);
4821                 }
4822                 else
4823                         elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
4824         }
4825
4826         /*
4827          * Allow a plugin to editorialize on the set of Paths for this base
4828          * relation.  It could add new paths (such as CustomPaths) by calling
4829          * add_path(), or delete or modify paths added by the core code.
4830          */
4831         if (set_rel_pathlist_hook)
4832                 (*set_rel_pathlist_hook) (root, rel, rti, rte);
4833
4834         /* Now find the cheapest of the paths for this rel */
4835         set_cheapest(rel);
4836 }
4837
4838 /*
4839  * stmt_beg callback is called when each query in PL/pgSQL function is about
4840  * to be executed.  At that timing, we save query string in the global variable
4841  * plpgsql_query_string to use it in planner hook.  It's safe to use one global
4842  * variable for the purpose, because its content is only necessary until
4843  * planner hook is called for the query, so recursive PL/pgSQL function calls
4844  * don't harm this mechanism.
4845  */
4846 static void
4847 pg_hint_plan_plpgsql_stmt_beg(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
4848 {
4849         plpgsql_recurse_level++;
4850 }
4851
4852 /*
4853  * stmt_end callback is called then each query in PL/pgSQL function has
4854  * finished.  At that timing, we clear plpgsql_query_string to tell planner
4855  * hook that next call is not for a query written in PL/pgSQL block.
4856  */
4857 static void
4858 pg_hint_plan_plpgsql_stmt_end(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
4859 {
4860         plpgsql_recurse_level--;
4861 }
4862
4863 void plpgsql_query_erase_callback(ResourceReleasePhase phase,
4864                                                                   bool isCommit,
4865                                                                   bool isTopLevel,
4866                                                                   void *arg)
4867 {
4868         if (!isTopLevel || phase != RESOURCE_RELEASE_AFTER_LOCKS)
4869                 return;
4870         /* Cancel plpgsql nest level*/
4871         plpgsql_recurse_level = 0;
4872 }
4873
4874 #define standard_join_search pg_hint_plan_standard_join_search
4875 #define join_search_one_level pg_hint_plan_join_search_one_level
4876 #define make_join_rel make_join_rel_wrapper
4877 #include "core.c"
4878
4879 #undef make_join_rel
4880 #define make_join_rel pg_hint_plan_make_join_rel
4881 #define add_paths_to_joinrel add_paths_to_joinrel_wrapper
4882 #include "make_join_rel.c"
4883
4884 #include "pg_stat_statements.c"