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) 2012-2021, 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/float.h"
  42 #include "utils/lsyscache.h"
  43 #include "utils/memutils.h"
  44 #include "utils/rel.h"
  45 #include "utils/snapmgr.h"
  46 #include "utils/syscache.h"
  47 #include "utils/resowner.h"
  48
  49 #include "catalog/pg_class.h"
  50
  51 #include "executor/spi.h"
  52 #include "catalog/pg_type.h"
  53
  54 #include "plpgsql.h"
  55
  56 /* partially copied from pg_stat_statements */
  57 #include "normalize_query.h"
  58
  59 /* PostgreSQL */
  60 #include "access/htup_details.h"
  61
  62 #ifdef PG_MODULE_MAGIC
  63 PG_MODULE_MAGIC;
  64 #endif
  65
  66 #define BLOCK_COMMENT_START             "/*"
  67 #define BLOCK_COMMENT_END               "*/"
  68 #define HINT_COMMENT_KEYWORD    "+"
  69 #define HINT_START                              BLOCK_COMMENT_START HINT_COMMENT_KEYWORD
  70 #define HINT_END                                BLOCK_COMMENT_END
  71
  72 /* hint keywords */
  73 #define HINT_SEQSCAN                    "SeqScan"
  74 #define HINT_INDEXSCAN                  "IndexScan"
  75 #define HINT_INDEXSCANREGEXP    "IndexScanRegexp"
  76 #define HINT_BITMAPSCAN                 "BitmapScan"
  77 #define HINT_BITMAPSCANREGEXP   "BitmapScanRegexp"
  78 #define HINT_TIDSCAN                    "TidScan"
  79 #define HINT_NOSEQSCAN                  "NoSeqScan"
  80 #define HINT_NOINDEXSCAN                "NoIndexScan"
  81 #define HINT_NOBITMAPSCAN               "NoBitmapScan"
  82 #define HINT_NOTIDSCAN                  "NoTidScan"
  83 #define HINT_INDEXONLYSCAN              "IndexOnlyScan"
  84 #define HINT_INDEXONLYSCANREGEXP        "IndexOnlyScanRegexp"
  85 #define HINT_NOINDEXONLYSCAN    "NoIndexOnlyScan"
  86 #define HINT_PARALLEL                   "Parallel"
  87
  88 #define HINT_NESTLOOP                   "NestLoop"
  89 #define HINT_MERGEJOIN                  "MergeJoin"
  90 #define HINT_HASHJOIN                   "HashJoin"
  91 #define HINT_NONESTLOOP                 "NoNestLoop"
  92 #define HINT_NOMERGEJOIN                "NoMergeJoin"
  93 #define HINT_NOHASHJOIN                 "NoHashJoin"
  94 #define HINT_LEADING                    "Leading"
  95 #define HINT_SET                                "Set"
  96 #define HINT_ROWS                               "Rows"
  97 #define HINT_MEMOIZE                    "Memoize"
  98 #define HINT_NOMEMOIZE                  "NoMemoize"
  99
 100 #define HINT_ARRAY_DEFAULT_INITSIZE 8
 101
 102 #define hint_ereport(str, detail) hint_parse_ereport(str, detail)
 103 #define hint_parse_ereport(str, detail) \
 104         do { \
 105                 ereport(pg_hint_plan_parse_message_level,               \
 106                         (errmsg("pg_hint_plan: hint syntax error at or near \"%s\"", (str)), \
 107                          errdetail detail)); \
 108         } while(0)
 109
 110 #define skip_space(str) \
 111         while (isspace(*str)) \
 112                 str++;
 113
 114 enum
 115 {
 116         ENABLE_SEQSCAN = 0x01,
 117         ENABLE_INDEXSCAN = 0x02,
 118         ENABLE_BITMAPSCAN = 0x04,
 119         ENABLE_TIDSCAN = 0x08,
 120         ENABLE_INDEXONLYSCAN = 0x10
 121 } SCAN_TYPE_BITS;
 122
 123 enum
 124 {
 125         ENABLE_NESTLOOP = 0x01,
 126         ENABLE_MERGEJOIN = 0x02,
 127         ENABLE_HASHJOIN = 0x04,
 128         ENABLE_MEMOIZE  = 0x08
 129 } JOIN_TYPE_BITS;
 130
 131 #define ENABLE_ALL_SCAN (ENABLE_SEQSCAN | ENABLE_INDEXSCAN | \
 132                                                  ENABLE_BITMAPSCAN | ENABLE_TIDSCAN | \
 133                                                  ENABLE_INDEXONLYSCAN)
 134 #define ENABLE_ALL_JOIN (ENABLE_NESTLOOP | ENABLE_MERGEJOIN | ENABLE_HASHJOIN)
 135 #define DISABLE_ALL_SCAN 0
 136 #define DISABLE_ALL_JOIN 0
 137
 138 /* hint keyword of enum type*/
 139 typedef enum HintKeyword
 140 {
 141         HINT_KEYWORD_SEQSCAN,
 142         HINT_KEYWORD_INDEXSCAN,
 143         HINT_KEYWORD_INDEXSCANREGEXP,
 144         HINT_KEYWORD_BITMAPSCAN,
 145         HINT_KEYWORD_BITMAPSCANREGEXP,
 146         HINT_KEYWORD_TIDSCAN,
 147         HINT_KEYWORD_NOSEQSCAN,
 148         HINT_KEYWORD_NOINDEXSCAN,
 149         HINT_KEYWORD_NOBITMAPSCAN,
 150         HINT_KEYWORD_NOTIDSCAN,
 151         HINT_KEYWORD_INDEXONLYSCAN,
 152         HINT_KEYWORD_INDEXONLYSCANREGEXP,
 153         HINT_KEYWORD_NOINDEXONLYSCAN,
 154
 155         HINT_KEYWORD_NESTLOOP,
 156         HINT_KEYWORD_MERGEJOIN,
 157         HINT_KEYWORD_HASHJOIN,
 158         HINT_KEYWORD_NONESTLOOP,
 159         HINT_KEYWORD_NOMERGEJOIN,
 160         HINT_KEYWORD_NOHASHJOIN,
 161
 162         HINT_KEYWORD_LEADING,
 163         HINT_KEYWORD_SET,
 164         HINT_KEYWORD_ROWS,
 165         HINT_KEYWORD_PARALLEL,
 166         HINT_KEYWORD_MEMOIZE,
 167         HINT_KEYWORD_NOMEMOIZE,
 168
 169         HINT_KEYWORD_UNRECOGNIZED
 170 } HintKeyword;
 171
 172 #define SCAN_HINT_ACCEPTS_INDEX_NAMES(kw) \
 173         (kw == HINT_KEYWORD_INDEXSCAN ||                        \
 174          kw == HINT_KEYWORD_INDEXSCANREGEXP ||          \
 175          kw == HINT_KEYWORD_INDEXONLYSCAN ||            \
 176          kw == HINT_KEYWORD_INDEXONLYSCANREGEXP ||      \
 177          kw == HINT_KEYWORD_BITMAPSCAN ||                               \
 178          kw == HINT_KEYWORD_BITMAPSCANREGEXP)
 179
 180
 181 typedef struct Hint Hint;
 182 typedef struct HintState HintState;
 183
 184 typedef Hint *(*HintCreateFunction) (const char *hint_str,
 185                                                                          const char *keyword,
 186                                                                          HintKeyword hint_keyword);
 187 typedef void (*HintDeleteFunction) (Hint *hint);
 188 typedef void (*HintDescFunction) (Hint *hint, StringInfo buf, bool nolf);
 189 typedef int (*HintCmpFunction) (const Hint *a, const Hint *b);
 190 typedef const char *(*HintParseFunction) (Hint *hint, HintState *hstate,
 191                                                                                   Query *parse, const char *str);
 192
 193 /* hint types */
 194 typedef enum HintType
 195 {
 196         HINT_TYPE_SCAN_METHOD,
 197         HINT_TYPE_JOIN_METHOD,
 198         HINT_TYPE_LEADING,
 199         HINT_TYPE_SET,
 200         HINT_TYPE_ROWS,
 201         HINT_TYPE_PARALLEL,
 202         HINT_TYPE_MEMOIZE,
 203
 204         NUM_HINT_TYPE
 205 } HintType;
 206
 207 typedef enum HintTypeBitmap
 208 {
 209         HINT_BM_SCAN_METHOD = 1,
 210         HINT_BM_PARALLEL = 2
 211 } HintTypeBitmap;
 212
 213 static const char *HintTypeName[] = {
 214         "scan method",
 215         "join method",
 216         "leading",
 217         "set",
 218         "rows",
 219         "parallel"
 220 };
 221
 222 /* hint status */
 223 typedef enum HintStatus
 224 {
 225         HINT_STATE_NOTUSED = 0,         /* specified relation not used in query */
 226         HINT_STATE_USED,                        /* hint is used */
 227         HINT_STATE_DUPLICATION,         /* specified hint duplication */
 228         HINT_STATE_ERROR                        /* execute error (parse error does not include
 229                                                                  * it) */
 230 } HintStatus;
 231
 232 #define hint_state_enabled(hint) ((hint)->base.state == HINT_STATE_NOTUSED || \
 233                                                                   (hint)->base.state == HINT_STATE_USED)
 234
 235 static unsigned int qno = 0;
 236 static unsigned int msgqno = 0;
 237 static char qnostr[32];
 238 static const char *current_hint_str = NULL;
 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         double                  init_paratup_cost;      /* parallel_tuple_cost */
 367         double                  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         List              **memoize_hint_level;
 379         LeadingHint       **leading_hint;               /* parsed Leading hints */
 380         SetHint           **set_hints;                  /* parsed Set hints */
 381         GucContext              context;                        /* which GUC parameters can we set? */
 382         RowsHint          **rows_hints;                 /* parsed Rows hints */
 383         ParallelHint  **parallel_hints;         /* parsed Parallel hints */
 384         JoinMethodHint **memoize_hints;         /* parsed Memoize hints */
 385 };
 386
 387 /*
 388  * Describes a hint parser module which is bound with particular hint keyword.
 389  */
 390 typedef struct HintParser
 391 {
 392         char                       *keyword;
 393         HintCreateFunction      create_func;
 394         HintKeyword                     hint_keyword;
 395 } HintParser;
 396
 397 /* Module callbacks */
 398 void            _PG_init(void);
 399 void            _PG_fini(void);
 400
 401 static void push_hint(HintState *hstate);
 402 static void pop_hint(void);
 403
 404 static PlannedStmt *pg_hint_plan_planner(Query *parse, const char *query_string,
 405                                                                                  int cursorOptions,
 406                                                                                  ParamListInfo boundParams);
 407 static RelOptInfo *pg_hint_plan_join_search(PlannerInfo *root,
 408                                                                                         int levels_needed,
 409                                                                                         List *initial_rels);
 410
 411 /* Scan method hint callbacks */
 412 static Hint *ScanMethodHintCreate(const char *hint_str, const char *keyword,
 413                                                                   HintKeyword hint_keyword);
 414 static void ScanMethodHintDelete(ScanMethodHint *hint);
 415 static void ScanMethodHintDesc(ScanMethodHint *hint, StringInfo buf, bool nolf);
 416 static int ScanMethodHintCmp(const ScanMethodHint *a, const ScanMethodHint *b);
 417 static const char *ScanMethodHintParse(ScanMethodHint *hint, HintState *hstate,
 418                                                                            Query *parse, const char *str);
 419
 420 /* Join method hint callbacks */
 421 static Hint *JoinMethodHintCreate(const char *hint_str, const char *keyword,
 422                                                                   HintKeyword hint_keyword);
 423 static void JoinMethodHintDelete(JoinMethodHint *hint);
 424 static void JoinMethodHintDesc(JoinMethodHint *hint, StringInfo buf, bool nolf);
 425 static int JoinMethodHintCmp(const JoinMethodHint *a, const JoinMethodHint *b);
 426 static const char *JoinMethodHintParse(JoinMethodHint *hint, HintState *hstate,
 427                                                                            Query *parse, const char *str);
 428
 429 /* Leading hint callbacks */
 430 static Hint *LeadingHintCreate(const char *hint_str, const char *keyword,
 431                                                            HintKeyword hint_keyword);
 432 static void LeadingHintDelete(LeadingHint *hint);
 433 static void LeadingHintDesc(LeadingHint *hint, StringInfo buf, bool nolf);
 434 static int LeadingHintCmp(const LeadingHint *a, const LeadingHint *b);
 435 static const char *LeadingHintParse(LeadingHint *hint, HintState *hstate,
 436                                                                         Query *parse, const char *str);
 437
 438 /* Set hint callbacks */
 439 static Hint *SetHintCreate(const char *hint_str, const char *keyword,
 440                                                    HintKeyword hint_keyword);
 441 static void SetHintDelete(SetHint *hint);
 442 static void SetHintDesc(SetHint *hint, StringInfo buf, bool nolf);
 443 static int SetHintCmp(const SetHint *a, const SetHint *b);
 444 static const char *SetHintParse(SetHint *hint, HintState *hstate, Query *parse,
 445                                                                 const char *str);
 446
 447 /* Rows hint callbacks */
 448 static Hint *RowsHintCreate(const char *hint_str, const char *keyword,
 449                                                         HintKeyword hint_keyword);
 450 static void RowsHintDelete(RowsHint *hint);
 451 static void RowsHintDesc(RowsHint *hint, StringInfo buf, bool nolf);
 452 static int RowsHintCmp(const RowsHint *a, const RowsHint *b);
 453 static const char *RowsHintParse(RowsHint *hint, HintState *hstate,
 454                                                                  Query *parse, const char *str);
 455
 456 /* Parallel hint callbacks */
 457 static Hint *ParallelHintCreate(const char *hint_str, const char *keyword,
 458                                                                 HintKeyword hint_keyword);
 459 static void ParallelHintDelete(ParallelHint *hint);
 460 static void ParallelHintDesc(ParallelHint *hint, StringInfo buf, bool nolf);
 461 static int ParallelHintCmp(const ParallelHint *a, const ParallelHint *b);
 462 static const char *ParallelHintParse(ParallelHint *hint, HintState *hstate,
 463                                                                          Query *parse, const char *str);
 464
 465 static Hint *MemoizeHintCreate(const char *hint_str, const char *keyword,
 466                                                            HintKeyword hint_keyword);
 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                                                                           List *other_rels_list,
 483                                                                           ListCell *other_rels);
 484 static void make_rels_by_clauseless_joins(PlannerInfo *root,
 485                                                                                   RelOptInfo *old_rel,
 486                                                                                   List *other_rels);
 487 static bool has_join_restriction(PlannerInfo *root, RelOptInfo *rel);
 488 static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
 489                                                                    RangeTblEntry *rte);
 490 RelOptInfo *pg_hint_plan_make_join_rel(PlannerInfo *root, RelOptInfo *rel1,
 491                                                                            RelOptInfo *rel2);
 492
 493 static void pg_hint_plan_plpgsql_stmt_beg(PLpgSQL_execstate *estate,
 494                                                                                   PLpgSQL_stmt *stmt);
 495 static void pg_hint_plan_plpgsql_stmt_end(PLpgSQL_execstate *estate,
 496                                                                                   PLpgSQL_stmt *stmt);
 497 static void plpgsql_query_erase_callback(ResourceReleasePhase phase,
 498                                                                                  bool isCommit,
 499                                                                                  bool isTopLevel,
 500                                                                                  void *arg);
 501 static int set_config_option_noerror(const char *name, const char *value,
 502                                                   GucContext context, GucSource source,
 503                                                   GucAction action, bool changeVal, int elevel);
 504 static void setup_scan_method_enforcement(ScanMethodHint *scanhint,
 505                                                                                   HintState *state);
 506 static int set_config_int32_option(const char *name, int32 value,
 507                                                                         GucContext context);
 508 static int set_config_double_option(const char *name, double value,
 509                                                                         GucContext context);
 510
 511 /* GUC variables */
 512 static bool     pg_hint_plan_enable_hint = true;
 513 static int debug_level = 0;
 514 static int      pg_hint_plan_parse_message_level = INFO;
 515 static int      pg_hint_plan_debug_message_level = LOG;
 516 /* Default is off, to keep backward compatibility. */
 517 static bool     pg_hint_plan_enable_hint_table = false;
 518
 519 static int plpgsql_recurse_level = 0;           /* PLpgSQL recursion level            */
 520 static int recurse_level = 0;           /* recursion level incl. direct SPI calls */
 521 static int hint_inhibit_level = 0;                      /* Inhibit hinting if this is above 0 */
 522                                                                                         /* (This could not be above 1)        */
 523 static int max_hint_nworkers = -1;              /* Maximum nworkers of Workers hints */
 524
 525 static const struct config_enum_entry parse_messages_level_options[] = {
 526         {"debug", DEBUG2, true},
 527         {"debug5", DEBUG5, false},
 528         {"debug4", DEBUG4, false},
 529         {"debug3", DEBUG3, false},
 530         {"debug2", DEBUG2, false},
 531         {"debug1", DEBUG1, false},
 532         {"log", LOG, false},
 533         {"info", INFO, false},
 534         {"notice", NOTICE, false},
 535         {"warning", WARNING, false},
 536         {"error", ERROR, false},
 537         /*
 538          * {"fatal", FATAL, true},
 539          * {"panic", PANIC, true},
 540          */
 541         {NULL, 0, false}
 542 };
 543
 544 static const struct config_enum_entry parse_debug_level_options[] = {
 545         {"off", 0, false},
 546         {"on", 1, false},
 547         {"detailed", 2, false},
 548         {"verbose", 3, false},
 549         {"0", 0, true},
 550         {"1", 1, true},
 551         {"2", 2, true},
 552         {"3", 3, true},
 553         {"no", 0, true},
 554         {"yes", 1, true},
 555         {"false", 0, true},
 556         {"true", 1, true},
 557         {NULL, 0, false}
 558 };
 559
 560 /* Saved hook values in case of unload */
 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
 565 /* Hold reference to currently active hint */
 566 static HintState *current_hint_state = NULL;
 567
 568 /*
 569  * List of hint contexts.  We treat the head of the list as the Top of the
 570  * context stack, so current_hint_state always points the first element of this
 571  * list.
 572  */
 573 static List *HintStateStack = NIL;
 574
 575 static const HintParser parsers[] = {
 576         {HINT_SEQSCAN, ScanMethodHintCreate, HINT_KEYWORD_SEQSCAN},
 577         {HINT_INDEXSCAN, ScanMethodHintCreate, HINT_KEYWORD_INDEXSCAN},
 578         {HINT_INDEXSCANREGEXP, ScanMethodHintCreate, HINT_KEYWORD_INDEXSCANREGEXP},
 579         {HINT_BITMAPSCAN, ScanMethodHintCreate, HINT_KEYWORD_BITMAPSCAN},
 580         {HINT_BITMAPSCANREGEXP, ScanMethodHintCreate,
 581          HINT_KEYWORD_BITMAPSCANREGEXP},
 582         {HINT_TIDSCAN, ScanMethodHintCreate, HINT_KEYWORD_TIDSCAN},
 583         {HINT_NOSEQSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOSEQSCAN},
 584         {HINT_NOINDEXSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOINDEXSCAN},
 585         {HINT_NOBITMAPSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOBITMAPSCAN},
 586         {HINT_NOTIDSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOTIDSCAN},
 587         {HINT_INDEXONLYSCAN, ScanMethodHintCreate, HINT_KEYWORD_INDEXONLYSCAN},
 588         {HINT_INDEXONLYSCANREGEXP, ScanMethodHintCreate,
 589          HINT_KEYWORD_INDEXONLYSCANREGEXP},
 590         {HINT_NOINDEXONLYSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOINDEXONLYSCAN},
 591
 592         {HINT_NESTLOOP, JoinMethodHintCreate, HINT_KEYWORD_NESTLOOP},
 593         {HINT_MERGEJOIN, JoinMethodHintCreate, HINT_KEYWORD_MERGEJOIN},
 594         {HINT_HASHJOIN, JoinMethodHintCreate, HINT_KEYWORD_HASHJOIN},
 595         {HINT_NONESTLOOP, JoinMethodHintCreate, HINT_KEYWORD_NONESTLOOP},
 596         {HINT_NOMERGEJOIN, JoinMethodHintCreate, HINT_KEYWORD_NOMERGEJOIN},
 597         {HINT_NOHASHJOIN, JoinMethodHintCreate, HINT_KEYWORD_NOHASHJOIN},
 598
 599         {HINT_LEADING, LeadingHintCreate, HINT_KEYWORD_LEADING},
 600         {HINT_SET, SetHintCreate, HINT_KEYWORD_SET},
 601         {HINT_ROWS, RowsHintCreate, HINT_KEYWORD_ROWS},
 602         {HINT_PARALLEL, ParallelHintCreate, HINT_KEYWORD_PARALLEL},
 603         {HINT_MEMOIZE, MemoizeHintCreate, HINT_KEYWORD_MEMOIZE},
 604         {HINT_NOMEMOIZE, MemoizeHintCreate, HINT_KEYWORD_NOMEMOIZE},
 605
 606         {NULL, NULL, HINT_KEYWORD_UNRECOGNIZED}
 607 };
 608
 609 PLpgSQL_plugin  plugin_funcs = {
 610         NULL,
 611         NULL,
 612         NULL,
 613         pg_hint_plan_plpgsql_stmt_beg,
 614         pg_hint_plan_plpgsql_stmt_end,
 615         NULL,
 616         NULL,
 617 };
 618
 619 /*
 620  * Module load callbacks
 621  */
 622 void
 623 _PG_init(void)
 624 {
 625         PLpgSQL_plugin  **var_ptr;
 626
 627         /* Define custom GUC variables. */
 628         DefineCustomBoolVariable("pg_hint_plan.enable_hint",
 629                          "Force planner to use plans specified in the hint comment preceding to the query.",
 630                                                          NULL,
 631                                                          &pg_hint_plan_enable_hint,
 632                                                          true,
 633                                                      PGC_USERSET,
 634                                                          0,
 635                                                          NULL,
 636                                                          NULL,
 637                                                          NULL);
 638
 639         DefineCustomEnumVariable("pg_hint_plan.debug_print",
 640                                                          "Logs results of hint parsing.",
 641                                                          NULL,
 642                                                          &debug_level,
 643                                                          false,
 644                                                          parse_debug_level_options,
 645                                                          PGC_USERSET,
 646                                                          0,
 647                                                          NULL,
 648                                                          NULL,
 649                                                          NULL);
 650
 651         DefineCustomEnumVariable("pg_hint_plan.parse_messages",
 652                                                          "Message level of parse errors.",
 653                                                          NULL,
 654                                                          &pg_hint_plan_parse_message_level,
 655                                                          INFO,
 656                                                          parse_messages_level_options,
 657                                                          PGC_USERSET,
 658                                                          0,
 659                                                          NULL,
 660                                                          NULL,
 661                                                          NULL);
 662
 663         DefineCustomEnumVariable("pg_hint_plan.message_level",
 664                                                          "Message level of debug messages.",
 665                                                          NULL,
 666                                                          &pg_hint_plan_debug_message_level,
 667                                                          LOG,
 668                                                          parse_messages_level_options,
 669                                                          PGC_USERSET,
 670                                                          0,
 671                                                          NULL,
 672                                                          NULL,
 673                                                          NULL);
 674
 675         DefineCustomBoolVariable("pg_hint_plan.enable_hint_table",
 676                                                          "Let pg_hint_plan look up the hint table.",
 677                                                          NULL,
 678                                                          &pg_hint_plan_enable_hint_table,
 679                                                          false,
 680                                                          PGC_USERSET,
 681                                                          0,
 682                                                          NULL,
 683                                                          NULL,
 684                                                          NULL);
 685
 686         /* Install hooks. */
 687         prev_planner = planner_hook;
 688         planner_hook = pg_hint_plan_planner;
 689         prev_join_search = join_search_hook;
 690         join_search_hook = pg_hint_plan_join_search;
 691         prev_set_rel_pathlist = set_rel_pathlist_hook;
 692         set_rel_pathlist_hook = pg_hint_plan_set_rel_pathlist;
 693
 694         /* setup PL/pgSQL plugin hook */
 695         var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
 696         *var_ptr = &plugin_funcs;
 697
 698         RegisterResourceReleaseCallback(plpgsql_query_erase_callback, NULL);
 699 }
 700
 701 /*
 702  * Module unload callback
 703  * XXX never called
 704  */
 705 void
 706 _PG_fini(void)
 707 {
 708         PLpgSQL_plugin  **var_ptr;
 709
 710         /* Uninstall hooks. */
 711         planner_hook = prev_planner;
 712         join_search_hook = prev_join_search;
 713         set_rel_pathlist_hook = prev_set_rel_pathlist;
 714
 715         /* uninstall PL/pgSQL plugin hook */
 716         var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
 717         *var_ptr = NULL;
 718 }
 719
 720 /*
 721  * create and delete functions the hint object
 722  */
 723
 724 static Hint *
 725 ScanMethodHintCreate(const char *hint_str, const char *keyword,
 726                                          HintKeyword hint_keyword)
 727 {
 728         ScanMethodHint *hint;
 729
 730         hint = palloc(sizeof(ScanMethodHint));
 731         hint->base.hint_str = hint_str;
 732         hint->base.keyword = keyword;
 733         hint->base.hint_keyword = hint_keyword;
 734         hint->base.type = HINT_TYPE_SCAN_METHOD;
 735         hint->base.state = HINT_STATE_NOTUSED;
 736         hint->base.delete_func = (HintDeleteFunction) ScanMethodHintDelete;
 737         hint->base.desc_func = (HintDescFunction) ScanMethodHintDesc;
 738         hint->base.cmp_func = (HintCmpFunction) ScanMethodHintCmp;
 739         hint->base.parse_func = (HintParseFunction) ScanMethodHintParse;
 740         hint->relname = NULL;
 741         hint->indexnames = NIL;
 742         hint->regexp = false;
 743         hint->enforce_mask = 0;
 744
 745         return (Hint *) hint;
 746 }
 747
 748 static void
 749 ScanMethodHintDelete(ScanMethodHint *hint)
 750 {
 751         if (!hint)
 752                 return;
 753
 754         if (hint->relname)
 755                 pfree(hint->relname);
 756         list_free_deep(hint->indexnames);
 757         pfree(hint);
 758 }
 759
 760 static Hint *
 761 JoinMethodHintCreate(const char *hint_str, const char *keyword,
 762                                          HintKeyword hint_keyword)
 763 {
 764         JoinMethodHint *hint;
 765
 766         hint = palloc(sizeof(JoinMethodHint));
 767         hint->base.hint_str = hint_str;
 768         hint->base.keyword = keyword;
 769         hint->base.hint_keyword = hint_keyword;
 770         hint->base.type = HINT_TYPE_JOIN_METHOD;
 771         hint->base.state = HINT_STATE_NOTUSED;
 772         hint->base.delete_func = (HintDeleteFunction) JoinMethodHintDelete;
 773         hint->base.desc_func = (HintDescFunction) JoinMethodHintDesc;
 774         hint->base.cmp_func = (HintCmpFunction) JoinMethodHintCmp;
 775         hint->base.parse_func = (HintParseFunction) JoinMethodHintParse;
 776         hint->nrels = 0;
 777         hint->inner_nrels = 0;
 778         hint->relnames = NULL;
 779         hint->enforce_mask = 0;
 780         hint->joinrelids = NULL;
 781         hint->inner_joinrelids = NULL;
 782
 783         return (Hint *) hint;
 784 }
 785
 786 static void
 787 JoinMethodHintDelete(JoinMethodHint *hint)
 788 {
 789         if (!hint)
 790                 return;
 791
 792         if (hint->relnames)
 793         {
 794                 int     i;
 795
 796                 for (i = 0; i < hint->nrels; i++)
 797                         pfree(hint->relnames[i]);
 798                 pfree(hint->relnames);
 799         }
 800
 801         bms_free(hint->joinrelids);
 802         bms_free(hint->inner_joinrelids);
 803         pfree(hint);
 804 }
 805
 806 static Hint *
 807 LeadingHintCreate(const char *hint_str, const char *keyword,
 808                                   HintKeyword hint_keyword)
 809 {
 810         LeadingHint        *hint;
 811
 812         hint = palloc(sizeof(LeadingHint));
 813         hint->base.hint_str = hint_str;
 814         hint->base.keyword = keyword;
 815         hint->base.hint_keyword = hint_keyword;
 816         hint->base.type = HINT_TYPE_LEADING;
 817         hint->base.state = HINT_STATE_NOTUSED;
 818         hint->base.delete_func = (HintDeleteFunction)LeadingHintDelete;
 819         hint->base.desc_func = (HintDescFunction) LeadingHintDesc;
 820         hint->base.cmp_func = (HintCmpFunction) LeadingHintCmp;
 821         hint->base.parse_func = (HintParseFunction) LeadingHintParse;
 822         hint->relations = NIL;
 823         hint->outer_inner = NULL;
 824
 825         return (Hint *) hint;
 826 }
 827
 828 static void
 829 LeadingHintDelete(LeadingHint *hint)
 830 {
 831         if (!hint)
 832                 return;
 833
 834         list_free_deep(hint->relations);
 835         if (hint->outer_inner)
 836                 pfree(hint->outer_inner);
 837         pfree(hint);
 838 }
 839
 840 static Hint *
 841 SetHintCreate(const char *hint_str, const char *keyword,
 842                           HintKeyword hint_keyword)
 843 {
 844         SetHint    *hint;
 845
 846         hint = palloc(sizeof(SetHint));
 847         hint->base.hint_str = hint_str;
 848         hint->base.keyword = keyword;
 849         hint->base.hint_keyword = hint_keyword;
 850         hint->base.type = HINT_TYPE_SET;
 851         hint->base.state = HINT_STATE_NOTUSED;
 852         hint->base.delete_func = (HintDeleteFunction) SetHintDelete;
 853         hint->base.desc_func = (HintDescFunction) SetHintDesc;
 854         hint->base.cmp_func = (HintCmpFunction) SetHintCmp;
 855         hint->base.parse_func = (HintParseFunction) SetHintParse;
 856         hint->name = NULL;
 857         hint->value = NULL;
 858         hint->words = NIL;
 859
 860         return (Hint *) hint;
 861 }
 862
 863 static void
 864 SetHintDelete(SetHint *hint)
 865 {
 866         if (!hint)
 867                 return;
 868
 869         if (hint->name)
 870                 pfree(hint->name);
 871         if (hint->value)
 872                 pfree(hint->value);
 873         if (hint->words)
 874                 list_free(hint->words);
 875         pfree(hint);
 876 }
 877
 878 static Hint *
 879 RowsHintCreate(const char *hint_str, const char *keyword,
 880                            HintKeyword hint_keyword)
 881 {
 882         RowsHint *hint;
 883
 884         hint = palloc(sizeof(RowsHint));
 885         hint->base.hint_str = hint_str;
 886         hint->base.keyword = keyword;
 887         hint->base.hint_keyword = hint_keyword;
 888         hint->base.type = HINT_TYPE_ROWS;
 889         hint->base.state = HINT_STATE_NOTUSED;
 890         hint->base.delete_func = (HintDeleteFunction) RowsHintDelete;
 891         hint->base.desc_func = (HintDescFunction) RowsHintDesc;
 892         hint->base.cmp_func = (HintCmpFunction) RowsHintCmp;
 893         hint->base.parse_func = (HintParseFunction) RowsHintParse;
 894         hint->nrels = 0;
 895         hint->inner_nrels = 0;
 896         hint->relnames = NULL;
 897         hint->joinrelids = NULL;
 898         hint->inner_joinrelids = NULL;
 899         hint->rows_str = NULL;
 900         hint->value_type = RVT_ABSOLUTE;
 901         hint->rows = 0;
 902
 903         return (Hint *) hint;
 904 }
 905
 906 static void
 907 RowsHintDelete(RowsHint *hint)
 908 {
 909         if (!hint)
 910                 return;
 911
 912         if (hint->relnames)
 913         {
 914                 int     i;
 915
 916                 for (i = 0; i < hint->nrels; i++)
 917                         pfree(hint->relnames[i]);
 918                 pfree(hint->relnames);
 919         }
 920
 921         bms_free(hint->joinrelids);
 922         bms_free(hint->inner_joinrelids);
 923         pfree(hint);
 924 }
 925
 926 static Hint *
 927 ParallelHintCreate(const char *hint_str, const char *keyword,
 928                                   HintKeyword hint_keyword)
 929 {
 930         ParallelHint *hint;
 931
 932         hint = palloc(sizeof(ParallelHint));
 933         hint->base.hint_str = hint_str;
 934         hint->base.keyword = keyword;
 935         hint->base.hint_keyword = hint_keyword;
 936         hint->base.type = HINT_TYPE_PARALLEL;
 937         hint->base.state = HINT_STATE_NOTUSED;
 938         hint->base.delete_func = (HintDeleteFunction) ParallelHintDelete;
 939         hint->base.desc_func = (HintDescFunction) ParallelHintDesc;
 940         hint->base.cmp_func = (HintCmpFunction) ParallelHintCmp;
 941         hint->base.parse_func = (HintParseFunction) ParallelHintParse;
 942         hint->relname = NULL;
 943         hint->nworkers = 0;
 944         hint->nworkers_str = "0";
 945
 946         return (Hint *) hint;
 947 }
 948
 949 static void
 950 ParallelHintDelete(ParallelHint *hint)
 951 {
 952         if (!hint)
 953                 return;
 954
 955         if (hint->relname)
 956                 pfree(hint->relname);
 957         pfree(hint);
 958 }
 959
 960
 961 static Hint *
 962 MemoizeHintCreate(const char *hint_str, const char *keyword,
 963                                   HintKeyword hint_keyword)
 964 {
 965         /*
 966          * MemoizeHintCreate shares the same struct with JoinMethodHint and the
 967          * only difference is the hint type.
 968          */
 969         JoinMethodHint *hint =
 970                 (JoinMethodHint *)JoinMethodHintCreate(hint_str, keyword, hint_keyword);
 971
 972         hint->base.type = HINT_TYPE_MEMOIZE;
 973
 974         return (Hint *) hint;
 975 }
 976
 977
 978 static HintState *
 979 HintStateCreate(void)
 980 {
 981         HintState   *hstate;
 982
 983         hstate = palloc(sizeof(HintState));
 984         hstate->hint_str = NULL;
 985         hstate->nall_hints = 0;
 986         hstate->max_all_hints = 0;
 987         hstate->all_hints = NULL;
 988         memset(hstate->num_hints, 0, sizeof(hstate->num_hints));
 989         hstate->scan_hints = NULL;
 990         hstate->init_scan_mask = 0;
 991         hstate->init_nworkers = 0;
 992         hstate->init_min_para_tablescan_size = 0;
 993         hstate->init_min_para_indexscan_size = 0;
 994         hstate->init_paratup_cost = 0;
 995         hstate->init_parasetup_cost = 0;
 996         hstate->current_root = NULL;
 997         hstate->parent_relid = 0;
 998         hstate->parent_scan_hint = NULL;
 999         hstate->parent_parallel_hint = NULL;
1000         hstate->parent_index_infos = NIL;
1001         hstate->join_hints = NULL;
1002         hstate->init_join_mask = 0;
1003         hstate->join_hint_level = NULL;
1004         hstate->memoize_hint_level = NULL;
1005         hstate->leading_hint = NULL;
1006         hstate->context = superuser() ? PGC_SUSET : PGC_USERSET;
1007         hstate->set_hints = NULL;
1008         hstate->rows_hints = NULL;
1009         hstate->parallel_hints = NULL;
1010
1011         return hstate;
1012 }
1013
1014 static void
1015 HintStateDelete(HintState *hstate)
1016 {
1017         int                     i;
1018
1019         if (!hstate)
1020                 return;
1021
1022         if (hstate->hint_str)
1023                 pfree(hstate->hint_str);
1024
1025         for (i = 0; i < hstate->num_hints[HINT_TYPE_SCAN_METHOD]; i++)
1026                 hstate->all_hints[i]->delete_func(hstate->all_hints[i]);
1027         if (hstate->all_hints)
1028                 pfree(hstate->all_hints);
1029         if (hstate->parent_index_infos)
1030                 list_free(hstate->parent_index_infos);
1031 }
1032
1033 /*
1034  * Copy given value into buf, with quoting with '"' if necessary.
1035  */
1036 static void
1037 quote_value(StringInfo buf, const char *value)
1038 {
1039         bool            need_quote = false;
1040         const char *str;
1041
1042         for (str = value; *str != '\0'; str++)
1043         {
1044                 if (isspace(*str) || *str == '(' || *str == ')' || *str == '"')
1045                 {
1046                         need_quote = true;
1047                         appendStringInfoCharMacro(buf, '"');
1048                         break;
1049                 }
1050         }
1051
1052         for (str = value; *str != '\0'; str++)
1053         {
1054                 if (*str == '"')
1055                         appendStringInfoCharMacro(buf, '"');
1056
1057                 appendStringInfoCharMacro(buf, *str);
1058         }
1059
1060         if (need_quote)
1061                 appendStringInfoCharMacro(buf, '"');
1062 }
1063
1064 static void
1065 ScanMethodHintDesc(ScanMethodHint *hint, StringInfo buf, bool nolf)
1066 {
1067         ListCell   *l;
1068
1069         appendStringInfo(buf, "%s(", hint->base.keyword);
1070         if (hint->relname != NULL)
1071         {
1072                 quote_value(buf, hint->relname);
1073                 foreach(l, hint->indexnames)
1074                 {
1075                         appendStringInfoCharMacro(buf, ' ');
1076                         quote_value(buf, (char *) lfirst(l));
1077                 }
1078         }
1079         appendStringInfoString(buf, ")");
1080         if (!nolf)
1081                 appendStringInfoChar(buf, '\n');
1082 }
1083
1084 static void
1085 JoinMethodHintDesc(JoinMethodHint *hint, StringInfo buf, bool nolf)
1086 {
1087         int     i;
1088
1089         appendStringInfo(buf, "%s(", hint->base.keyword);
1090         if (hint->relnames != NULL)
1091         {
1092                 quote_value(buf, hint->relnames[0]);
1093                 for (i = 1; i < hint->nrels; i++)
1094                 {
1095                         appendStringInfoCharMacro(buf, ' ');
1096                         quote_value(buf, hint->relnames[i]);
1097                 }
1098         }
1099         appendStringInfoString(buf, ")");
1100         if (!nolf)
1101                 appendStringInfoChar(buf, '\n');
1102 }
1103
1104 static void
1105 OuterInnerDesc(OuterInnerRels *outer_inner, StringInfo buf)
1106 {
1107         if (outer_inner->relation == NULL)
1108         {
1109                 bool            is_first;
1110                 ListCell   *l;
1111
1112                 is_first = true;
1113
1114                 appendStringInfoCharMacro(buf, '(');
1115                 foreach(l, outer_inner->outer_inner_pair)
1116                 {
1117                         if (is_first)
1118                                 is_first = false;
1119                         else
1120                                 appendStringInfoCharMacro(buf, ' ');
1121
1122                         OuterInnerDesc(lfirst(l), buf);
1123                 }
1124
1125                 appendStringInfoCharMacro(buf, ')');
1126         }
1127         else
1128                 quote_value(buf, outer_inner->relation);
1129 }
1130
1131 static void
1132 LeadingHintDesc(LeadingHint *hint, StringInfo buf, bool nolf)
1133 {
1134         appendStringInfo(buf, "%s(", HINT_LEADING);
1135         if (hint->outer_inner == NULL)
1136         {
1137                 ListCell   *l;
1138                 bool            is_first;
1139
1140                 is_first = true;
1141
1142                 foreach(l, hint->relations)
1143                 {
1144                         if (is_first)
1145                                 is_first = false;
1146                         else
1147                                 appendStringInfoCharMacro(buf, ' ');
1148
1149                         quote_value(buf, (char *) lfirst(l));
1150                 }
1151         }
1152         else
1153                 OuterInnerDesc(hint->outer_inner, buf);
1154
1155         appendStringInfoString(buf, ")");
1156         if (!nolf)
1157                 appendStringInfoChar(buf, '\n');
1158 }
1159
1160 static void
1161 SetHintDesc(SetHint *hint, StringInfo buf, bool nolf)
1162 {
1163         bool            is_first = true;
1164         ListCell   *l;
1165
1166         appendStringInfo(buf, "%s(", HINT_SET);
1167         foreach(l, hint->words)
1168         {
1169                 if (is_first)
1170                         is_first = false;
1171                 else
1172                         appendStringInfoCharMacro(buf, ' ');
1173
1174                 quote_value(buf, (char *) lfirst(l));
1175         }
1176         appendStringInfo(buf, ")");
1177         if (!nolf)
1178                 appendStringInfoChar(buf, '\n');
1179 }
1180
1181 static void
1182 RowsHintDesc(RowsHint *hint, StringInfo buf, bool nolf)
1183 {
1184         int     i;
1185
1186         appendStringInfo(buf, "%s(", hint->base.keyword);
1187         if (hint->relnames != NULL)
1188         {
1189                 quote_value(buf, hint->relnames[0]);
1190                 for (i = 1; i < hint->nrels; i++)
1191                 {
1192                         appendStringInfoCharMacro(buf, ' ');
1193                         quote_value(buf, hint->relnames[i]);
1194                 }
1195         }
1196         if (hint->rows_str != NULL)
1197                 appendStringInfo(buf, " %s", hint->rows_str);
1198         appendStringInfoString(buf, ")");
1199         if (!nolf)
1200                 appendStringInfoChar(buf, '\n');
1201 }
1202
1203 static void
1204 ParallelHintDesc(ParallelHint *hint, StringInfo buf, bool nolf)
1205 {
1206         appendStringInfo(buf, "%s(", hint->base.keyword);
1207         if (hint->relname != NULL)
1208         {
1209                 quote_value(buf, hint->relname);
1210
1211                 /* number of workers  */
1212                 appendStringInfoCharMacro(buf, ' ');
1213                 quote_value(buf, hint->nworkers_str);
1214                 /* application mode of num of workers */
1215                 appendStringInfoCharMacro(buf, ' ');
1216                 appendStringInfoString(buf,
1217                                                            (hint->force_parallel ? "hard" : "soft"));
1218         }
1219         appendStringInfoString(buf, ")");
1220         if (!nolf)
1221                 appendStringInfoChar(buf, '\n');
1222 }
1223
1224 /*
1225  * Append string which represents all hints in a given state to buf, with
1226  * preceding title with them.
1227  */
1228 static void
1229 desc_hint_in_state(HintState *hstate, StringInfo buf, const char *title,
1230                                    HintStatus state, bool nolf)
1231 {
1232         int     i, nshown;
1233
1234         appendStringInfo(buf, "%s:", title);
1235         if (!nolf)
1236                 appendStringInfoChar(buf, '\n');
1237
1238         nshown = 0;
1239         for (i = 0; i < hstate->nall_hints; i++)
1240         {
1241                 if (hstate->all_hints[i]->state != state)
1242                         continue;
1243
1244                 hstate->all_hints[i]->desc_func(hstate->all_hints[i], buf, nolf);
1245                 nshown++;
1246         }
1247
1248         if (nolf && nshown == 0)
1249                 appendStringInfoString(buf, "(none)");
1250 }
1251
1252 /*
1253  * Dump contents of given hstate to server log with log level LOG.
1254  */
1255 static void
1256 HintStateDump(HintState *hstate)
1257 {
1258         StringInfoData  buf;
1259
1260         if (!hstate)
1261         {
1262                 elog(pg_hint_plan_debug_message_level, "pg_hint_plan:\nno hint");
1263                 return;
1264         }
1265
1266         initStringInfo(&buf);
1267
1268         appendStringInfoString(&buf, "pg_hint_plan:\n");
1269         desc_hint_in_state(hstate, &buf, "used hint", HINT_STATE_USED, false);
1270         desc_hint_in_state(hstate, &buf, "not used hint", HINT_STATE_NOTUSED, false);
1271         desc_hint_in_state(hstate, &buf, "duplication hint", HINT_STATE_DUPLICATION, false);
1272         desc_hint_in_state(hstate, &buf, "error hint", HINT_STATE_ERROR, false);
1273
1274         ereport(pg_hint_plan_debug_message_level,
1275                         (errmsg ("%s", buf.data)));
1276
1277         pfree(buf.data);
1278 }
1279
1280 static void
1281 HintStateDump2(HintState *hstate)
1282 {
1283         StringInfoData  buf;
1284
1285         if (!hstate)
1286         {
1287                 elog(pg_hint_plan_debug_message_level,
1288                          "pg_hint_plan%s: HintStateDump: no hint", qnostr);
1289                 return;
1290         }
1291
1292         initStringInfo(&buf);
1293         appendStringInfo(&buf, "pg_hint_plan%s: HintStateDump: ", qnostr);
1294         desc_hint_in_state(hstate, &buf, "{used hints", HINT_STATE_USED, true);
1295         desc_hint_in_state(hstate, &buf, "}, {not used hints", HINT_STATE_NOTUSED, true);
1296         desc_hint_in_state(hstate, &buf, "}, {duplicate hints", HINT_STATE_DUPLICATION, true);
1297         desc_hint_in_state(hstate, &buf, "}, {error hints", HINT_STATE_ERROR, true);
1298         appendStringInfoChar(&buf, '}');
1299
1300         ereport(pg_hint_plan_debug_message_level,
1301                         (errmsg("%s", buf.data),
1302                          errhidestmt(true),
1303                          errhidecontext(true)));
1304
1305         pfree(buf.data);
1306 }
1307
1308 /*
1309  * compare functions
1310  */
1311
1312 static int
1313 RelnameCmp(const void *a, const void *b)
1314 {
1315         const char *relnamea = *((const char **) a);
1316         const char *relnameb = *((const char **) b);
1317
1318         return strcmp(relnamea, relnameb);
1319 }
1320
1321 static int
1322 ScanMethodHintCmp(const ScanMethodHint *a, const ScanMethodHint *b)
1323 {
1324         return RelnameCmp(&a->relname, &b->relname);
1325 }
1326
1327 static int
1328 JoinMethodHintCmp(const JoinMethodHint *a, const JoinMethodHint *b)
1329 {
1330         int     i;
1331
1332         if (a->nrels != b->nrels)
1333                 return a->nrels - b->nrels;
1334
1335         for (i = 0; i < a->nrels; i++)
1336         {
1337                 int     result;
1338                 if ((result = RelnameCmp(&a->relnames[i], &b->relnames[i])) != 0)
1339                         return result;
1340         }
1341
1342         return 0;
1343 }
1344
1345 static int
1346 LeadingHintCmp(const LeadingHint *a, const LeadingHint *b)
1347 {
1348         return 0;
1349 }
1350
1351 static int
1352 SetHintCmp(const SetHint *a, const SetHint *b)
1353 {
1354         return strcmp(a->name, b->name);
1355 }
1356
1357 static int
1358 RowsHintCmp(const RowsHint *a, const RowsHint *b)
1359 {
1360         int     i;
1361
1362         if (a->nrels != b->nrels)
1363                 return a->nrels - b->nrels;
1364
1365         for (i = 0; i < a->nrels; i++)
1366         {
1367                 int     result;
1368                 if ((result = RelnameCmp(&a->relnames[i], &b->relnames[i])) != 0)
1369                         return result;
1370         }
1371
1372         return 0;
1373 }
1374
1375 static int
1376 ParallelHintCmp(const ParallelHint *a, const ParallelHint *b)
1377 {
1378         return RelnameCmp(&a->relname, &b->relname);
1379 }
1380
1381 static int
1382 HintCmp(const void *a, const void *b)
1383 {
1384         const Hint *hinta = *((const Hint **) a);
1385         const Hint *hintb = *((const Hint **) b);
1386
1387         if (hinta->type != hintb->type)
1388                 return hinta->type - hintb->type;
1389         if (hinta->state == HINT_STATE_ERROR)
1390                 return -1;
1391         if (hintb->state == HINT_STATE_ERROR)
1392                 return 1;
1393         return hinta->cmp_func(hinta, hintb);
1394 }
1395
1396 /*
1397  * Returns byte offset of hint b from hint a.  If hint a was specified before
1398  * b, positive value is returned.
1399  */
1400 static int
1401 HintCmpWithPos(const void *a, const void *b)
1402 {
1403         const Hint *hinta = *((const Hint **) a);
1404         const Hint *hintb = *((const Hint **) b);
1405         int             result;
1406
1407         result = HintCmp(a, b);
1408         if (result == 0)
1409                 result = hinta->hint_str - hintb->hint_str;
1410
1411         return result;
1412 }
1413
1414 /*
1415  * parse functions
1416  */
1417 static const char *
1418 parse_keyword(const char *str, StringInfo buf)
1419 {
1420         skip_space(str);
1421
1422         while (!isspace(*str) && *str != '(' && *str != '\0')
1423                 appendStringInfoCharMacro(buf, *str++);
1424
1425         return str;
1426 }
1427
1428 static const char *
1429 skip_parenthesis(const char *str, char parenthesis)
1430 {
1431         skip_space(str);
1432
1433         if (*str != parenthesis)
1434         {
1435                 if (parenthesis == '(')
1436                         hint_ereport(str, ("Opening parenthesis is necessary."));
1437                 else if (parenthesis == ')')
1438                         hint_ereport(str, ("Closing parenthesis is necessary."));
1439
1440                 return NULL;
1441         }
1442
1443         str++;
1444
1445         return str;
1446 }
1447
1448 /*
1449  * Parse a token from str, and store malloc'd copy into word.  A token can be
1450  * quoted with '"'.  Return value is pointer to unparsed portion of original
1451  * string, or NULL if an error occurred.
1452  *
1453  * Parsed token is truncated within NAMEDATALEN-1 bytes, when truncate is true.
1454  */
1455 static const char *
1456 parse_quoted_value(const char *str, char **word, bool truncate)
1457 {
1458         StringInfoData  buf;
1459         bool                    in_quote;
1460
1461         /* Skip leading spaces. */
1462         skip_space(str);
1463
1464         initStringInfo(&buf);
1465         if (*str == '"')
1466         {
1467                 str++;
1468                 in_quote = true;
1469         }
1470         else
1471                 in_quote = false;
1472
1473         while (true)
1474         {
1475                 if (in_quote)
1476                 {
1477                         /* Double quotation must be closed. */
1478                         if (*str == '\0')
1479                         {
1480                                 pfree(buf.data);
1481                                 hint_ereport(str, ("Unterminated quoted string."));
1482                                 return NULL;
1483                         }
1484
1485                         /*
1486                          * Skip escaped double quotation.
1487                          *
1488                          * We don't allow slash-asterisk and asterisk-slash (delimiters of
1489                          * block comments) to be an object name, so users must specify
1490                          * alias for such object names.
1491                          *
1492                          * Those special names can be allowed if we care escaped slashes
1493                          * and asterisks, but we don't.
1494                          */
1495                         if (*str == '"')
1496                         {
1497                                 str++;
1498                                 if (*str != '"')
1499                                         break;
1500                         }
1501                 }
1502                 else if (isspace(*str) || *str == '(' || *str == ')' || *str == '"' ||
1503                                  *str == '\0')
1504                         break;
1505
1506                 appendStringInfoCharMacro(&buf, *str++);
1507         }
1508
1509         if (buf.len == 0)
1510         {
1511                 hint_ereport(str, ("Zero-length delimited string."));
1512
1513                 pfree(buf.data);
1514
1515                 return NULL;
1516         }
1517
1518         /* Truncate name if it's too long */
1519         if (truncate)
1520                 truncate_identifier(buf.data, strlen(buf.data), true);
1521
1522         *word = buf.data;
1523
1524         return str;
1525 }
1526
1527 static OuterInnerRels *
1528 OuterInnerRelsCreate(char *name, List *outer_inner_list)
1529 {
1530         OuterInnerRels *outer_inner;
1531
1532         outer_inner = palloc(sizeof(OuterInnerRels));
1533         outer_inner->relation = name;
1534         outer_inner->outer_inner_pair = outer_inner_list;
1535
1536         return outer_inner;
1537 }
1538
1539 static const char *
1540 parse_parentheses_Leading_in(const char *str, OuterInnerRels **outer_inner)
1541 {
1542         List   *outer_inner_pair = NIL;
1543
1544         if ((str = skip_parenthesis(str, '(')) == NULL)
1545                 return NULL;
1546
1547         skip_space(str);
1548
1549         /* Store words in parentheses into outer_inner_list. */
1550         while(*str != ')' && *str != '\0')
1551         {
1552                 OuterInnerRels *outer_inner_rels;
1553
1554                 if (*str == '(')
1555                 {
1556                         str = parse_parentheses_Leading_in(str, &outer_inner_rels);
1557                         if (str == NULL)
1558                                 break;
1559                 }
1560                 else
1561                 {
1562                         char   *name;
1563
1564                         if ((str = parse_quoted_value(str, &name, true)) == NULL)
1565                                 break;
1566                         else
1567                                 outer_inner_rels = OuterInnerRelsCreate(name, NIL);
1568                 }
1569
1570                 outer_inner_pair = lappend(outer_inner_pair, outer_inner_rels);
1571                 skip_space(str);
1572         }
1573
1574         if (str == NULL ||
1575                 (str = skip_parenthesis(str, ')')) == NULL)
1576         {
1577                 list_free(outer_inner_pair);
1578                 return NULL;
1579         }
1580
1581         *outer_inner = OuterInnerRelsCreate(NULL, outer_inner_pair);
1582
1583         return str;
1584 }
1585
1586 static const char *
1587 parse_parentheses_Leading(const char *str, List **name_list,
1588         OuterInnerRels **outer_inner)
1589 {
1590         char   *name;
1591         bool    truncate = true;
1592
1593         if ((str = skip_parenthesis(str, '(')) == NULL)
1594                 return NULL;
1595
1596         skip_space(str);
1597         if (*str =='(')
1598         {
1599                 if ((str = parse_parentheses_Leading_in(str, outer_inner)) == NULL)
1600                         return NULL;
1601         }
1602         else
1603         {
1604                 /* Store words in parentheses into name_list. */
1605                 while(*str != ')' && *str != '\0')
1606                 {
1607                         if ((str = parse_quoted_value(str, &name, truncate)) == NULL)
1608                         {
1609                                 list_free(*name_list);
1610                                 return NULL;
1611                         }
1612
1613                         *name_list = lappend(*name_list, name);
1614                         skip_space(str);
1615                 }
1616         }
1617
1618         if ((str = skip_parenthesis(str, ')')) == NULL)
1619                 return NULL;
1620         return str;
1621 }
1622
1623 static const char *
1624 parse_parentheses(const char *str, List **name_list, HintKeyword keyword)
1625 {
1626         char   *name;
1627         bool    truncate = true;
1628
1629         if ((str = skip_parenthesis(str, '(')) == NULL)
1630                 return NULL;
1631
1632         skip_space(str);
1633
1634         /* Store words in parentheses into name_list. */
1635         while(*str != ')' && *str != '\0')
1636         {
1637                 if ((str = parse_quoted_value(str, &name, truncate)) == NULL)
1638                 {
1639                         list_free(*name_list);
1640                         return NULL;
1641                 }
1642
1643                 *name_list = lappend(*name_list, name);
1644                 skip_space(str);
1645
1646                 if (keyword == HINT_KEYWORD_INDEXSCANREGEXP ||
1647                         keyword == HINT_KEYWORD_INDEXONLYSCANREGEXP ||
1648                         keyword == HINT_KEYWORD_BITMAPSCANREGEXP ||
1649                         keyword == HINT_KEYWORD_SET)
1650                 {
1651                         truncate = false;
1652                 }
1653         }
1654
1655         if ((str = skip_parenthesis(str, ')')) == NULL)
1656                 return NULL;
1657         return str;
1658 }
1659
1660 static void
1661 parse_hints(HintState *hstate, Query *parse, const char *str)
1662 {
1663         StringInfoData  buf;
1664         char               *head;
1665
1666         initStringInfo(&buf);
1667         while (*str != '\0')
1668         {
1669                 const HintParser *parser;
1670
1671                 /* in error message, we output the comment including the keyword. */
1672                 head = (char *) str;
1673
1674                 /* parse only the keyword of the hint. */
1675                 resetStringInfo(&buf);
1676                 str = parse_keyword(str, &buf);
1677
1678                 for (parser = parsers; parser->keyword != NULL; parser++)
1679                 {
1680                         char   *keyword = parser->keyword;
1681                         Hint   *hint;
1682
1683                         if (pg_strcasecmp(buf.data, keyword) != 0)
1684                                 continue;
1685
1686                         hint = parser->create_func(head, keyword, parser->hint_keyword);
1687
1688                         /* parser of each hint does parse in a parenthesis. */
1689                         if ((str = hint->parse_func(hint, hstate, parse, str)) == NULL)
1690                         {
1691                                 hint->delete_func(hint);
1692                                 pfree(buf.data);
1693                                 return;
1694                         }
1695
1696                         /*
1697                          * Add hint information into all_hints array.  If we don't have
1698                          * enough space, double the array.
1699                          */
1700                         if (hstate->nall_hints == 0)
1701                         {
1702                                 hstate->max_all_hints = HINT_ARRAY_DEFAULT_INITSIZE;
1703                                 hstate->all_hints = (Hint **)
1704                                         palloc(sizeof(Hint *) * hstate->max_all_hints);
1705                         }
1706                         else if (hstate->nall_hints == hstate->max_all_hints)
1707                         {
1708                                 hstate->max_all_hints *= 2;
1709                                 hstate->all_hints = (Hint **)
1710                                         repalloc(hstate->all_hints,
1711                                                          sizeof(Hint *) * hstate->max_all_hints);
1712                         }
1713
1714                         hstate->all_hints[hstate->nall_hints] = hint;
1715                         hstate->nall_hints++;
1716
1717                         skip_space(str);
1718
1719                         break;
1720                 }
1721
1722                 if (parser->keyword == NULL)
1723                 {
1724                         hint_ereport(head,
1725                                                  ("Unrecognized hint keyword \"%s\".", buf.data));
1726                         pfree(buf.data);
1727                         return;
1728                 }
1729         }
1730
1731         pfree(buf.data);
1732 }
1733
1734
1735 /*
1736  * Get hints from table by client-supplied query string and application name.
1737  */
1738 static const char *
1739 get_hints_from_table(const char *client_query, const char *client_application)
1740 {
1741         const char *search_query =
1742                 "SELECT hints "
1743                 "  FROM hint_plan.hints "
1744                 " WHERE norm_query_string = $1 "
1745                 "   AND ( application_name = $2 "
1746                 "    OR application_name = '' ) "
1747                 " ORDER BY application_name DESC";
1748         static SPIPlanPtr plan = NULL;
1749         char   *hints = NULL;
1750         Oid             argtypes[2] = { TEXTOID, TEXTOID };
1751         Datum   values[2];
1752         char    nulls[2] = {' ', ' '};
1753         text   *qry;
1754         text   *app;
1755
1756         PG_TRY();
1757         {
1758                 bool snapshot_set = false;
1759
1760                 hint_inhibit_level++;
1761
1762                 if (!ActiveSnapshotSet())
1763                 {
1764                         PushActiveSnapshot(GetTransactionSnapshot());
1765                         snapshot_set = true;
1766                 }
1767
1768                 SPI_connect();
1769
1770                 if (plan == NULL)
1771                 {
1772                         SPIPlanPtr      p;
1773                         p = SPI_prepare(search_query, 2, argtypes);
1774                         plan = SPI_saveplan(p);
1775                         SPI_freeplan(p);
1776                 }
1777
1778                 qry = cstring_to_text(client_query);
1779                 app = cstring_to_text(client_application);
1780                 values[0] = PointerGetDatum(qry);
1781                 values[1] = PointerGetDatum(app);
1782
1783                 SPI_execute_plan(plan, values, nulls, true, 1);
1784
1785                 if (SPI_processed > 0)
1786                 {
1787                         char    *buf;
1788
1789                         hints = SPI_getvalue(SPI_tuptable->vals[0],
1790                                                                  SPI_tuptable->tupdesc, 1);
1791                         /*
1792                          * Here we use SPI_palloc to ensure that hints string is valid even
1793                          * after SPI_finish call.  We can't use simple palloc because it
1794                          * allocates memory in SPI's context and that context is deleted in
1795                          * SPI_finish.
1796                          */
1797                         buf = SPI_palloc(strlen(hints) + 1);
1798                         strcpy(buf, hints);
1799                         hints = buf;
1800                 }
1801
1802                 SPI_finish();
1803
1804                 if (snapshot_set)
1805                         PopActiveSnapshot();
1806
1807                 hint_inhibit_level--;
1808         }
1809         PG_CATCH();
1810         {
1811                 hint_inhibit_level--;
1812                 PG_RE_THROW();
1813         }
1814         PG_END_TRY();
1815
1816         return hints;
1817 }
1818
1819 /*
1820  * Get hints from the head block comment in client-supplied query string.
1821  */
1822 static const char *
1823 get_hints_from_comment(const char *p)
1824 {
1825         const char *hint_head;
1826         char       *head;
1827         char       *tail;
1828         int                     len;
1829
1830         if (p == NULL)
1831                 return NULL;
1832
1833         /* extract query head comment. */
1834         hint_head = strstr(p, HINT_START);
1835         if (hint_head == NULL)
1836                 return NULL;
1837         for (;p < hint_head; p++)
1838         {
1839                 /*
1840                  * Allow these characters precedes hint comment:
1841                  *   - digits
1842                  *   - alphabets which are in ASCII range
1843                  *   - space, tabs and new-lines
1844                  *   - underscores, for identifier
1845                  *   - commas, for SELECT clause, EXPLAIN and PREPARE
1846                  *   - parentheses, for EXPLAIN and PREPARE
1847                  *
1848                  * Note that we don't use isalpha() nor isalnum() in ctype.h here to
1849                  * avoid behavior which depends on locale setting.
1850                  */
1851                 if (!(*p >= '0' && *p <= '9') &&
1852                         !(*p >= 'A' && *p <= 'Z') &&
1853                         !(*p >= 'a' && *p <= 'z') &&
1854                         !isspace(*p) &&
1855                         *p != '_' &&
1856                         *p != ',' &&
1857                         *p != '(' && *p != ')')
1858                         return NULL;
1859         }
1860
1861         len = strlen(HINT_START);
1862         head = (char *) p;
1863         p += len;
1864         skip_space(p);
1865
1866         /* find hint end keyword. */
1867         if ((tail = strstr(p, HINT_END)) == NULL)
1868         {
1869                 hint_ereport(head, ("Unterminated block comment."));
1870                 return NULL;
1871         }
1872
1873         /* We don't support nested block comments. */
1874         if ((head = strstr(p, BLOCK_COMMENT_START)) != NULL && head < tail)
1875         {
1876                 hint_ereport(head, ("Nested block comments are not supported."));
1877                 return NULL;
1878         }
1879
1880         /* Make a copy of hint. */
1881         len = tail - p;
1882         head = palloc(len + 1);
1883         memcpy(head, p, len);
1884         head[len] = '\0';
1885         p = head;
1886
1887         return p;
1888 }
1889
1890 /*
1891  * Parse hints that got, create hint struct from parse tree and parse hints.
1892  */
1893 static HintState *
1894 create_hintstate(Query *parse, const char *hints)
1895 {
1896         const char *p;
1897         int                     i;
1898         HintState   *hstate;
1899
1900         if (hints == NULL)
1901                 return NULL;
1902
1903         /* -1 means that no Parallel hint is specified. */
1904         max_hint_nworkers = -1;
1905
1906         p = hints;
1907         hstate = HintStateCreate();
1908         hstate->hint_str = (char *) hints;
1909
1910         /* parse each hint. */
1911         parse_hints(hstate, parse, p);
1912
1913         /* When nothing specified a hint, we free HintState and returns NULL. */
1914         if (hstate->nall_hints == 0)
1915         {
1916                 HintStateDelete(hstate);
1917                 return NULL;
1918         }
1919
1920         /* Sort hints in order of original position. */
1921         qsort(hstate->all_hints, hstate->nall_hints, sizeof(Hint *),
1922                   HintCmpWithPos);
1923
1924         /* Count number of hints per hint-type. */
1925         for (i = 0; i < hstate->nall_hints; i++)
1926         {
1927                 Hint   *cur_hint = hstate->all_hints[i];
1928                 hstate->num_hints[cur_hint->type]++;
1929         }
1930
1931         /*
1932          * If an object (or a set of objects) has multiple hints of same hint-type,
1933          * only the last hint is valid and others are ignored in planning.
1934          * Hints except the last are marked as 'duplicated' to remember the order.
1935          */
1936         for (i = 0; i < hstate->nall_hints - 1; i++)
1937         {
1938                 Hint   *cur_hint = hstate->all_hints[i];
1939                 Hint   *next_hint = hstate->all_hints[i + 1];
1940
1941                 /*
1942                  * Leading hint is marked as 'duplicated' in transform_join_hints.
1943                  */
1944                 if (cur_hint->type == HINT_TYPE_LEADING &&
1945                         next_hint->type == HINT_TYPE_LEADING)
1946                         continue;
1947
1948                 /*
1949                  * Note that we need to pass addresses of hint pointers, because
1950                  * HintCmp is designed to sort array of Hint* by qsort.
1951                  */
1952                 if (HintCmp(&cur_hint, &next_hint) == 0)
1953                 {
1954                         hint_ereport(cur_hint->hint_str,
1955                                                  ("Conflict %s hint.", HintTypeName[cur_hint->type]));
1956                         cur_hint->state = HINT_STATE_DUPLICATION;
1957                 }
1958         }
1959
1960         /*
1961          * Make sure that per-type array pointers point proper position in the
1962          * array which consists of all hints.
1963          */
1964         hstate->scan_hints = (ScanMethodHint **) hstate->all_hints;
1965         hstate->join_hints = (JoinMethodHint **) (hstate->scan_hints +
1966                 hstate->num_hints[HINT_TYPE_SCAN_METHOD]);
1967         hstate->leading_hint = (LeadingHint **) (hstate->join_hints +
1968                 hstate->num_hints[HINT_TYPE_JOIN_METHOD]);
1969         hstate->set_hints = (SetHint **) (hstate->leading_hint +
1970                 hstate->num_hints[HINT_TYPE_LEADING]);
1971         hstate->rows_hints = (RowsHint **) (hstate->set_hints +
1972                 hstate->num_hints[HINT_TYPE_SET]);
1973         hstate->parallel_hints = (ParallelHint **) (hstate->rows_hints +
1974                 hstate->num_hints[HINT_TYPE_ROWS]);
1975         hstate->memoize_hints = (JoinMethodHint **) (hstate->parallel_hints +
1976                 hstate->num_hints[HINT_TYPE_PARALLEL]);
1977
1978         return hstate;
1979 }
1980
1981 /*
1982  * Parse inside of parentheses of scan-method hints.
1983  */
1984 static const char *
1985 ScanMethodHintParse(ScanMethodHint *hint, HintState *hstate, Query *parse,
1986                                         const char *str)
1987 {
1988         const char         *keyword = hint->base.keyword;
1989         HintKeyword             hint_keyword = hint->base.hint_keyword;
1990         List               *name_list = NIL;
1991         int                             length;
1992
1993         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
1994                 return NULL;
1995
1996         /* Parse relation name and index name(s) if given hint accepts. */
1997         length = list_length(name_list);
1998
1999         /* at least twp parameters required */
2000         if (length < 1)
2001         {
2002                 hint_ereport(str,
2003                                          ("%s hint requires a relation.",  hint->base.keyword));
2004                 hint->base.state = HINT_STATE_ERROR;
2005                 return str;
2006         }
2007
2008         hint->relname = linitial(name_list);
2009         hint->indexnames = list_delete_first(name_list);
2010
2011         /* check whether the hint accepts index name(s) */
2012         if (length > 1 && !SCAN_HINT_ACCEPTS_INDEX_NAMES(hint_keyword))
2013         {
2014                 hint_ereport(str,
2015                                          ("%s hint accepts only one relation.",
2016                                           hint->base.keyword));
2017                 hint->base.state = HINT_STATE_ERROR;
2018                 return str;
2019         }
2020
2021         /* Set a bit for specified hint. */
2022         switch (hint_keyword)
2023         {
2024                 case HINT_KEYWORD_SEQSCAN:
2025                         hint->enforce_mask = ENABLE_SEQSCAN;
2026                         break;
2027                 case HINT_KEYWORD_INDEXSCAN:
2028                         hint->enforce_mask = ENABLE_INDEXSCAN;
2029                         break;
2030                 case HINT_KEYWORD_INDEXSCANREGEXP:
2031                         hint->enforce_mask = ENABLE_INDEXSCAN;
2032                         hint->regexp = true;
2033                         break;
2034                 case HINT_KEYWORD_BITMAPSCAN:
2035                         hint->enforce_mask = ENABLE_BITMAPSCAN;
2036                         break;
2037                 case HINT_KEYWORD_BITMAPSCANREGEXP:
2038                         hint->enforce_mask = ENABLE_BITMAPSCAN;
2039                         hint->regexp = true;
2040                         break;
2041                 case HINT_KEYWORD_TIDSCAN:
2042                         hint->enforce_mask = ENABLE_TIDSCAN;
2043                         break;
2044                 case HINT_KEYWORD_NOSEQSCAN:
2045                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_SEQSCAN;
2046                         break;
2047                 case HINT_KEYWORD_NOINDEXSCAN:
2048                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_INDEXSCAN;
2049                         break;
2050                 case HINT_KEYWORD_NOBITMAPSCAN:
2051                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_BITMAPSCAN;
2052                         break;
2053                 case HINT_KEYWORD_NOTIDSCAN:
2054                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_TIDSCAN;
2055                         break;
2056                 case HINT_KEYWORD_INDEXONLYSCAN:
2057                         hint->enforce_mask = ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN;
2058                         break;
2059                 case HINT_KEYWORD_INDEXONLYSCANREGEXP:
2060                         hint->enforce_mask = ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN;
2061                         hint->regexp = true;
2062                         break;
2063                 case HINT_KEYWORD_NOINDEXONLYSCAN:
2064                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_INDEXONLYSCAN;
2065                         break;
2066                 default:
2067                         hint_ereport(str, ("Unrecognized hint keyword \"%s\".", keyword));
2068                         return NULL;
2069                         break;
2070         }
2071
2072         return str;
2073 }
2074
2075 static const char *
2076 JoinMethodHintParse(JoinMethodHint *hint, HintState *hstate, Query *parse,
2077                                         const char *str)
2078 {
2079         const char         *keyword = hint->base.keyword;
2080         HintKeyword             hint_keyword = hint->base.hint_keyword;
2081         List               *name_list = NIL;
2082
2083         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
2084                 return NULL;
2085
2086         hint->nrels = list_length(name_list);
2087
2088         if (hint->nrels > 0)
2089         {
2090                 ListCell   *l;
2091                 int                     i = 0;
2092
2093                 /*
2094                  * Transform relation names from list to array to sort them with qsort
2095                  * after.
2096                  */
2097                 hint->relnames = palloc(sizeof(char *) * hint->nrels);
2098                 foreach (l, name_list)
2099                 {
2100                         hint->relnames[i] = lfirst(l);
2101                         i++;
2102                 }
2103         }
2104
2105         list_free(name_list);
2106
2107         /* A join hint requires at least two relations */
2108         if (hint->nrels < 2)
2109         {
2110                 hint_ereport(str,
2111                                          ("%s hint requires at least two relations.",
2112                                           hint->base.keyword));
2113                 hint->base.state = HINT_STATE_ERROR;
2114                 return str;
2115         }
2116
2117         /* Sort hints in alphabetical order of relation names. */
2118         qsort(hint->relnames, hint->nrels, sizeof(char *), RelnameCmp);
2119
2120         switch (hint_keyword)
2121         {
2122                 case HINT_KEYWORD_NESTLOOP:
2123                         hint->enforce_mask = ENABLE_NESTLOOP;
2124                         break;
2125                 case HINT_KEYWORD_MERGEJOIN:
2126                         hint->enforce_mask = ENABLE_MERGEJOIN;
2127                         break;
2128                 case HINT_KEYWORD_HASHJOIN:
2129                         hint->enforce_mask = ENABLE_HASHJOIN;
2130                         break;
2131                 case HINT_KEYWORD_NONESTLOOP:
2132                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_NESTLOOP;
2133                         break;
2134                 case HINT_KEYWORD_NOMERGEJOIN:
2135                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_MERGEJOIN;
2136                         break;
2137                 case HINT_KEYWORD_NOHASHJOIN:
2138                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_HASHJOIN;
2139                         break;
2140                 case HINT_KEYWORD_MEMOIZE:
2141                 case HINT_KEYWORD_NOMEMOIZE:
2142                         /* nothing to do here */
2143                         break;
2144                 default:
2145                         hint_ereport(str, ("Unrecognized hint keyword \"%s\".", keyword));
2146                         return NULL;
2147                         break;
2148         }
2149
2150         return str;
2151 }
2152
2153 static bool
2154 OuterInnerPairCheck(OuterInnerRels *outer_inner)
2155 {
2156         ListCell *l;
2157         if (outer_inner->outer_inner_pair == NIL)
2158         {
2159                 if (outer_inner->relation)
2160                         return true;
2161                 else
2162                         return false;
2163         }
2164
2165         if (list_length(outer_inner->outer_inner_pair) == 2)
2166         {
2167                 foreach(l, outer_inner->outer_inner_pair)
2168                 {
2169                         if (!OuterInnerPairCheck(lfirst(l)))
2170                                 return false;
2171                 }
2172         }
2173         else
2174                 return false;
2175
2176         return true;
2177 }
2178
2179 static List *
2180 OuterInnerList(OuterInnerRels *outer_inner)
2181 {
2182         List               *outer_inner_list = NIL;
2183         ListCell           *l;
2184         OuterInnerRels *outer_inner_rels;
2185
2186         foreach(l, outer_inner->outer_inner_pair)
2187         {
2188                 outer_inner_rels = (OuterInnerRels *)(lfirst(l));
2189
2190                 if (outer_inner_rels->relation != NULL)
2191                         outer_inner_list = lappend(outer_inner_list,
2192                                                                            outer_inner_rels->relation);
2193                 else
2194                         outer_inner_list = list_concat(outer_inner_list,
2195                                                                                    OuterInnerList(outer_inner_rels));
2196         }
2197         return outer_inner_list;
2198 }
2199
2200 static const char *
2201 LeadingHintParse(LeadingHint *hint, HintState *hstate, Query *parse,
2202                                  const char *str)
2203 {
2204         List               *name_list = NIL;
2205         OuterInnerRels *outer_inner = NULL;
2206
2207         if ((str = parse_parentheses_Leading(str, &name_list, &outer_inner)) ==
2208                 NULL)
2209                 return NULL;
2210
2211         if (outer_inner != NULL)
2212                 name_list = OuterInnerList(outer_inner);
2213
2214         hint->relations = name_list;
2215         hint->outer_inner = outer_inner;
2216
2217         /* A Leading hint requires at least two relations */
2218         if ( hint->outer_inner == NULL && list_length(hint->relations) < 2)
2219         {
2220                 hint_ereport(hint->base.hint_str,
2221                                          ("%s hint requires at least two relations.",
2222                                           HINT_LEADING));
2223                 hint->base.state = HINT_STATE_ERROR;
2224         }
2225         else if (hint->outer_inner != NULL &&
2226                          !OuterInnerPairCheck(hint->outer_inner))
2227         {
2228                 hint_ereport(hint->base.hint_str,
2229                                          ("%s hint requires two sets of relations when parentheses nests.",
2230                                           HINT_LEADING));
2231                 hint->base.state = HINT_STATE_ERROR;
2232         }
2233
2234         return str;
2235 }
2236
2237 static const char *
2238 SetHintParse(SetHint *hint, HintState *hstate, Query *parse, const char *str)
2239 {
2240         List   *name_list = NIL;
2241
2242         if ((str = parse_parentheses(str, &name_list, hint->base.hint_keyword))
2243                 == NULL)
2244                 return NULL;
2245
2246         hint->words = name_list;
2247
2248         /* We need both name and value to set GUC parameter. */
2249         if (list_length(name_list) == 2)
2250         {
2251                 hint->name = linitial(name_list);
2252                 hint->value = lsecond(name_list);
2253         }
2254         else
2255         {
2256                 hint_ereport(hint->base.hint_str,
2257                                          ("%s hint requires name and value of GUC parameter.",
2258                                           HINT_SET));
2259                 hint->base.state = HINT_STATE_ERROR;
2260         }
2261
2262         return str;
2263 }
2264
2265 static const char *
2266 RowsHintParse(RowsHint *hint, HintState *hstate, Query *parse,
2267                           const char *str)
2268 {
2269         HintKeyword             hint_keyword = hint->base.hint_keyword;
2270         List               *name_list = NIL;
2271         char               *rows_str;
2272         char               *end_ptr;
2273         ListCell   *l;
2274         int                     i = 0;
2275
2276         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
2277                 return NULL;
2278
2279         /* Last element must be rows specification */
2280         hint->nrels = list_length(name_list) - 1;
2281
2282         if (hint->nrels < 1)
2283         {
2284                 hint_ereport(str,
2285                                          ("%s hint needs at least one relation followed by one correction term.",
2286                                           hint->base.keyword));
2287                 hint->base.state = HINT_STATE_ERROR;
2288
2289                 return str;
2290         }
2291
2292
2293         /*
2294          * Transform relation names from list to array to sort them with qsort
2295          * after.
2296          */
2297         hint->relnames = palloc(sizeof(char *) * hint->nrels);
2298         foreach (l, name_list)
2299         {
2300                 if (hint->nrels <= i)
2301                         break;
2302                 hint->relnames[i] = lfirst(l);
2303                 i++;
2304         }
2305
2306         /* Retieve rows estimation */
2307         rows_str = list_nth(name_list, hint->nrels);
2308         hint->rows_str = rows_str;              /* store as-is for error logging */
2309         if (rows_str[0] == '#')
2310         {
2311                 hint->value_type = RVT_ABSOLUTE;
2312                 rows_str++;
2313         }
2314         else if (rows_str[0] == '+')
2315         {
2316                 hint->value_type = RVT_ADD;
2317                 rows_str++;
2318         }
2319         else if (rows_str[0] == '-')
2320         {
2321                 hint->value_type = RVT_SUB;
2322                 rows_str++;
2323         }
2324         else if (rows_str[0] == '*')
2325         {
2326                 hint->value_type = RVT_MULTI;
2327                 rows_str++;
2328         }
2329         else
2330         {
2331                 hint_ereport(rows_str, ("Unrecognized rows value type notation."));
2332                 hint->base.state = HINT_STATE_ERROR;
2333                 return str;
2334         }
2335         hint->rows = strtod(rows_str, &end_ptr);
2336         if (*end_ptr)
2337         {
2338                 hint_ereport(rows_str,
2339                                          ("%s hint requires valid number as rows estimation.",
2340                                           hint->base.keyword));
2341                 hint->base.state = HINT_STATE_ERROR;
2342                 return str;
2343         }
2344
2345         /* A join hint requires at least two relations */
2346         if (hint->nrels < 2)
2347         {
2348                 hint_ereport(str,
2349                                          ("%s hint requires at least two relations.",
2350                                           hint->base.keyword));
2351                 hint->base.state = HINT_STATE_ERROR;
2352                 return str;
2353         }
2354
2355         list_free(name_list);
2356
2357         /* Sort relnames in alphabetical order. */
2358         qsort(hint->relnames, hint->nrels, sizeof(char *), RelnameCmp);
2359
2360         return str;
2361 }
2362
2363 static const char *
2364 ParallelHintParse(ParallelHint *hint, HintState *hstate, Query *parse,
2365                                   const char *str)
2366 {
2367         HintKeyword             hint_keyword = hint->base.hint_keyword;
2368         List               *name_list = NIL;
2369         int                             length;
2370         char   *end_ptr;
2371         int             nworkers;
2372         bool    force_parallel = false;
2373
2374         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
2375                 return NULL;
2376
2377         /* Parse relation name and index name(s) if given hint accepts. */
2378         length = list_length(name_list);
2379
2380         if (length < 2 || length > 3)
2381         {
2382                 hint_ereport(")",
2383                                          ("wrong number of arguments (%d): %s",
2384                                           length,  hint->base.keyword));
2385                 hint->base.state = HINT_STATE_ERROR;
2386                 return str;
2387         }
2388
2389         hint->relname = linitial(name_list);
2390
2391         /* The second parameter is number of workers */
2392         hint->nworkers_str = list_nth(name_list, 1);
2393         nworkers = strtod(hint->nworkers_str, &end_ptr);
2394         if (*end_ptr || nworkers < 0 || nworkers > max_worker_processes)
2395         {
2396                 if (*end_ptr)
2397                         hint_ereport(hint->nworkers_str,
2398                                                  ("number of workers must be a number: %s",
2399                                                   hint->base.keyword));
2400                 else if (nworkers < 0)
2401                         hint_ereport(hint->nworkers_str,
2402                                                  ("number of workers must be positive: %s",
2403                                                   hint->base.keyword));
2404                 else if (nworkers > max_worker_processes)
2405                         hint_ereport(hint->nworkers_str,
2406                                                  ("number of workers = %d is larger than max_worker_processes(%d): %s",
2407                                                   nworkers, max_worker_processes, hint->base.keyword));
2408
2409                 hint->base.state = HINT_STATE_ERROR;
2410         }
2411
2412         hint->nworkers = nworkers;
2413
2414         /* optional third parameter is specified */
2415         if (length == 3)
2416         {
2417                 const char *modeparam = (const char *)list_nth(name_list, 2);
2418                 if (pg_strcasecmp(modeparam, "hard") == 0)
2419                         force_parallel = true;
2420                 else if (pg_strcasecmp(modeparam, "soft") != 0)
2421                 {
2422                         hint_ereport(modeparam,
2423                                                  ("enforcement must be soft or hard: %s",
2424                                                          hint->base.keyword));
2425                         hint->base.state = HINT_STATE_ERROR;
2426                 }
2427         }
2428
2429         hint->force_parallel = force_parallel;
2430
2431         if (hint->base.state != HINT_STATE_ERROR &&
2432                 nworkers > max_hint_nworkers)
2433                 max_hint_nworkers = nworkers;
2434
2435         return str;
2436 }
2437
2438 /*
2439  * set GUC parameter functions
2440  */
2441
2442 static int
2443 get_current_scan_mask()
2444 {
2445         int mask = 0;
2446
2447         if (enable_seqscan)
2448                 mask |= ENABLE_SEQSCAN;
2449         if (enable_indexscan)
2450                 mask |= ENABLE_INDEXSCAN;
2451         if (enable_bitmapscan)
2452                 mask |= ENABLE_BITMAPSCAN;
2453         if (enable_tidscan)
2454                 mask |= ENABLE_TIDSCAN;
2455         if (enable_indexonlyscan)
2456                 mask |= ENABLE_INDEXONLYSCAN;
2457
2458         return mask;
2459 }
2460
2461 static int
2462 get_current_join_mask()
2463 {
2464         int mask = 0;
2465
2466         if (enable_nestloop)
2467                 mask |= ENABLE_NESTLOOP;
2468         if (enable_mergejoin)
2469                 mask |= ENABLE_MERGEJOIN;
2470         if (enable_hashjoin)
2471                 mask |= ENABLE_HASHJOIN;
2472         if (enable_memoize)
2473                 mask |= ENABLE_MEMOIZE;
2474
2475         return mask;
2476 }
2477
2478 /*
2479  * Sets GUC prameters without throwing exception. Reutrns false if something
2480  * wrong.
2481  */
2482 static int
2483 set_config_option_noerror(const char *name, const char *value,
2484                                                   GucContext context, GucSource source,
2485                                                   GucAction action, bool changeVal, int elevel)
2486 {
2487         int                             result = 0;
2488         MemoryContext   ccxt = CurrentMemoryContext;
2489
2490         PG_TRY();
2491         {
2492                 result = set_config_option(name, value, context, source,
2493                                                                    action, changeVal, 0, false);
2494         }
2495         PG_CATCH();
2496         {
2497                 ErrorData          *errdata;
2498
2499                 /* Save error info */
2500                 MemoryContextSwitchTo(ccxt);
2501                 errdata = CopyErrorData();
2502                 FlushErrorState();
2503
2504                 ereport(elevel,
2505                                 (errcode(errdata->sqlerrcode),
2506                                  errmsg("%s", errdata->message),
2507                                  errdata->detail ? errdetail("%s", errdata->detail) : 0,
2508                                  errdata->hint ? errhint("%s", errdata->hint) : 0));
2509                 msgqno = qno;
2510                 FreeErrorData(errdata);
2511         }
2512         PG_END_TRY();
2513
2514         return result;
2515 }
2516
2517 /*
2518  * Sets GUC parameter of int32 type without throwing exceptions. Returns false
2519  * if something wrong.
2520  */
2521 static int
2522 set_config_int32_option(const char *name, int32 value, GucContext context)
2523 {
2524         char buf[16];   /* enough for int32 */
2525
2526         if (snprintf(buf, 16, "%d", value) < 0)
2527         {
2528                 ereport(pg_hint_plan_parse_message_level,
2529                                 (errmsg ("Failed to convert integer to string: %d", value)));
2530                 return false;
2531         }
2532
2533         return
2534                 set_config_option_noerror(name, buf, context,
2535                                                                   PGC_S_SESSION, GUC_ACTION_SAVE, true,
2536                                                                   pg_hint_plan_parse_message_level);
2537 }
2538
2539 /*
2540  * Sets GUC parameter of double type without throwing exceptions. Returns false
2541  * if something wrong.
2542  */
2543 static int
2544 set_config_double_option(const char *name, double value, GucContext context)
2545 {
2546         char *buf = float8out_internal(value);
2547         int       result;
2548
2549         result = set_config_option_noerror(name, buf, context,
2550                                                                            PGC_S_SESSION, GUC_ACTION_SAVE, true,
2551                                                                            pg_hint_plan_parse_message_level);
2552         pfree(buf);
2553         return result;
2554 }
2555
2556 /* setup scan method enforcement according to given options */
2557 static void
2558 setup_guc_enforcement(SetHint **options, int noptions, GucContext context)
2559 {
2560         int     i;
2561
2562         for (i = 0; i < noptions; i++)
2563         {
2564                 SetHint    *hint = options[i];
2565                 int                     result;
2566
2567                 if (!hint_state_enabled(hint))
2568                         continue;
2569
2570                 result = set_config_option_noerror(hint->name, hint->value, context,
2571                                                                                    PGC_S_SESSION, GUC_ACTION_SAVE, true,
2572                                                                                    pg_hint_plan_parse_message_level);
2573                 if (result != 0)
2574                         hint->base.state = HINT_STATE_USED;
2575                 else
2576                         hint->base.state = HINT_STATE_ERROR;
2577         }
2578
2579         return;
2580 }
2581
2582 /*
2583  * Setup parallel execution environment.
2584  *
2585  * If hint is not NULL, set up using it, elsewise reset to initial environment.
2586  */
2587 static void
2588 setup_parallel_plan_enforcement(ParallelHint *hint, HintState *state)
2589 {
2590         if (hint)
2591         {
2592                 hint->base.state = HINT_STATE_USED;
2593                 set_config_int32_option("max_parallel_workers_per_gather",
2594                                                                 hint->nworkers, state->context);
2595         }
2596         else
2597                 set_config_int32_option("max_parallel_workers_per_gather",
2598                                                                 state->init_nworkers, state->context);
2599
2600         /* force means that enforce parallel as far as possible */
2601         if (hint && hint->force_parallel && hint->nworkers > 0)
2602         {
2603                 set_config_double_option("parallel_tuple_cost", 0.0, state->context);
2604                 set_config_double_option("parallel_setup_cost", 0.0, state->context);
2605                 set_config_int32_option("min_parallel_table_scan_size", 0,
2606                                                                 state->context);
2607                 set_config_int32_option("min_parallel_index_scan_size", 0,
2608                                                                 state->context);
2609         }
2610         else
2611         {
2612                 set_config_double_option("parallel_tuple_cost",
2613                                                                 state->init_paratup_cost, state->context);
2614                 set_config_double_option("parallel_setup_cost",
2615                                                                 state->init_parasetup_cost, state->context);
2616                 set_config_int32_option("min_parallel_table_scan_size",
2617                                                                 state->init_min_para_tablescan_size,
2618                                                                 state->context);
2619                 set_config_int32_option("min_parallel_index_scan_size",
2620                                                                 state->init_min_para_indexscan_size,
2621                                                                 state->context);
2622         }
2623 }
2624
2625 #define SET_CONFIG_OPTION(name, type_bits) \
2626         set_config_option_noerror((name), \
2627                 (mask & (type_bits)) ? "true" : "false", \
2628                 context, PGC_S_SESSION, GUC_ACTION_SAVE, true, ERROR)
2629
2630
2631 /*
2632  * Setup GUC environment to enforce scan methods. If scanhint is NULL, reset
2633  * GUCs to the saved state in state.
2634  */
2635 static void
2636 setup_scan_method_enforcement(ScanMethodHint *scanhint, HintState *state)
2637 {
2638         unsigned char   enforce_mask = state->init_scan_mask;
2639         GucContext              context = state->context;
2640         unsigned char   mask;
2641
2642         if (scanhint)
2643         {
2644                 enforce_mask = scanhint->enforce_mask;
2645                 scanhint->base.state = HINT_STATE_USED;
2646         }
2647
2648         if (enforce_mask == ENABLE_SEQSCAN || enforce_mask == ENABLE_INDEXSCAN ||
2649                 enforce_mask == ENABLE_BITMAPSCAN || enforce_mask == ENABLE_TIDSCAN
2650                 || enforce_mask == (ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN)
2651                 )
2652                 mask = enforce_mask;
2653         else
2654                 mask = enforce_mask & current_hint_state->init_scan_mask;
2655
2656         SET_CONFIG_OPTION("enable_seqscan", ENABLE_SEQSCAN);
2657         SET_CONFIG_OPTION("enable_indexscan", ENABLE_INDEXSCAN);
2658         SET_CONFIG_OPTION("enable_bitmapscan", ENABLE_BITMAPSCAN);
2659         SET_CONFIG_OPTION("enable_tidscan", ENABLE_TIDSCAN);
2660         SET_CONFIG_OPTION("enable_indexonlyscan", ENABLE_INDEXONLYSCAN);
2661 }
2662
2663 static void
2664 set_join_config_options(unsigned char enforce_mask, bool set_memoize,
2665                                                 GucContext context)
2666 {
2667         unsigned char   mask;
2668
2669         if (enforce_mask == ENABLE_NESTLOOP || enforce_mask == ENABLE_MERGEJOIN ||
2670                 enforce_mask == ENABLE_HASHJOIN)
2671                 mask = enforce_mask;
2672         else
2673                 mask = enforce_mask & current_hint_state->init_join_mask;
2674
2675         SET_CONFIG_OPTION("enable_nestloop", ENABLE_NESTLOOP);
2676         SET_CONFIG_OPTION("enable_mergejoin", ENABLE_MERGEJOIN);
2677         SET_CONFIG_OPTION("enable_hashjoin", ENABLE_HASHJOIN);
2678
2679         if (set_memoize)
2680                 SET_CONFIG_OPTION("enable_memoize", ENABLE_MEMOIZE);
2681
2682         /*
2683          * Hash join may be rejected for the reason of estimated memory usage. Try
2684          * getting rid of that limitation.
2685          */
2686         if (enforce_mask == ENABLE_HASHJOIN)
2687         {
2688                 char                    buf[32];
2689                 int                             new_multipler;
2690
2691                 /* See final_cost_hashjoin(). */
2692                 new_multipler = MAX_KILOBYTES / work_mem;
2693
2694                 /* See guc.c for the upper limit */
2695                 if (new_multipler >= 1000)
2696                         new_multipler = 1000;
2697
2698                 if (new_multipler > hash_mem_multiplier)
2699                 {
2700                         snprintf(buf, sizeof(buf), UINT64_FORMAT, (uint64)new_multipler);
2701                         set_config_option_noerror("hash_mem_multiplier", buf,
2702                                                                           context, PGC_S_SESSION, GUC_ACTION_SAVE,
2703                                                                           true, ERROR);
2704                 }
2705         }
2706 }
2707
2708 /*
2709  * Push a hint into hint stack which is implemented with List struct.  Head of
2710  * list is top of stack.
2711  */
2712 static void
2713 push_hint(HintState *hstate)
2714 {
2715         /* Prepend new hint to the list means pushing to stack. */
2716         HintStateStack = lcons(hstate, HintStateStack);
2717
2718         /* Pushed hint is the one which should be used hereafter. */
2719         current_hint_state = hstate;
2720 }
2721
2722 /* Pop a hint from hint stack.  Popped hint is automatically discarded. */
2723 static void
2724 pop_hint(void)
2725 {
2726         /* Hint stack must not be empty. */
2727         if(HintStateStack == NIL)
2728                 elog(ERROR, "hint stack is empty");
2729
2730         /*
2731          * Take a hint at the head from the list, and free it.  Switch
2732          * current_hint_state to point new head (NULL if the list is empty).
2733          */
2734         HintStateStack = list_delete_first(HintStateStack);
2735         HintStateDelete(current_hint_state);
2736         if(HintStateStack == NIL)
2737                 current_hint_state = NULL;
2738         else
2739                 current_hint_state = (HintState *) lfirst(list_head(HintStateStack));
2740 }
2741
2742 /*
2743  * Retrieve and store hint string from given query or from the hint table.
2744  */
2745 static void
2746 get_current_hint_string(Query *query, const char *query_str)
2747 {
2748         MemoryContext   oldcontext;
2749
2750         /* do nothing while scanning hint table */
2751         if (hint_inhibit_level > 0)
2752                 return;
2753
2754         /* Make sure trashing old hint string */
2755         if (current_hint_str)
2756         {
2757                 pfree((void *)current_hint_str);
2758                 current_hint_str = NULL;
2759         }
2760
2761         /* Return if nothing to do. */
2762         if (!pg_hint_plan_enable_hint || !query_str)
2763                 return;
2764
2765         /* increment the query number */
2766         qnostr[0] = 0;
2767         if (debug_level > 1)
2768                 snprintf(qnostr, sizeof(qnostr), "[qno=0x%x]", qno++);
2769         qno++;
2770
2771         /* search the hint table for a hint if requested */
2772         if (pg_hint_plan_enable_hint_table)
2773         {
2774                 JumbleState        *jstate;
2775                 int                             query_len;
2776                 char               *normalized_query;
2777
2778                 jstate = JumbleQuery(query, query_str);
2779
2780                 /*
2781                  * Normalize the query string by replacing constants with '?'
2782                  */
2783                 /*
2784                  * Search hint string which is stored keyed by query string
2785                  * and application name.  The query string is normalized to allow
2786                  * fuzzy matching.
2787                  *
2788                  * Adding 1 byte to query_len ensures that the returned string has
2789                  * a terminating NULL.
2790                  */
2791                 query_len = strlen(query_str) + 1;
2792                 normalized_query =
2793                         generate_normalized_query(jstate, query_str, 0, &query_len);
2794
2795                 /*
2796                  * find a hint for the normalized query. the result should be in
2797                  * TopMemoryContext
2798                  */
2799                 oldcontext = MemoryContextSwitchTo(TopMemoryContext);
2800                 current_hint_str =
2801                         get_hints_from_table(normalized_query, application_name);
2802                 MemoryContextSwitchTo(oldcontext);
2803
2804                 if (debug_level > 1)
2805                 {
2806                         if (current_hint_str)
2807                                 ereport(pg_hint_plan_debug_message_level,
2808                                                 (errmsg("pg_hint_plan[qno=0x%x]: "
2809                                                                 "hints from table: \"%s\": "
2810                                                                 "normalized_query=\"%s\", "
2811                                                                 "application name =\"%s\"",
2812                                                                 qno, current_hint_str,
2813                                                                 normalized_query, application_name),
2814                                                  errhidestmt(msgqno != qno),
2815                                                  errhidecontext(msgqno != qno)));
2816                         else
2817                                 ereport(pg_hint_plan_debug_message_level,
2818                                                 (errmsg("pg_hint_plan[qno=0x%x]: "
2819                                                                 "no match found in table:  "
2820                                                                 "application name = \"%s\", "
2821                                                                 "normalized_query=\"%s\"",
2822                                                                 qno, application_name,
2823                                                                 normalized_query),
2824                                                  errhidestmt(msgqno != qno),
2825                                                  errhidecontext(msgqno != qno)));
2826
2827                         msgqno = qno;
2828                 }
2829
2830                 /* retrun if we have hint string here */
2831                 if (current_hint_str)
2832                         return;
2833         }
2834
2835         /* get hints from the comment */
2836         oldcontext = MemoryContextSwitchTo(TopMemoryContext);
2837         current_hint_str = get_hints_from_comment(query_str);
2838         MemoryContextSwitchTo(oldcontext);
2839
2840         if (debug_level > 1)
2841         {
2842                 if (debug_level == 1 && query_str && debug_query_string &&
2843                         strcmp(query_str, debug_query_string))
2844                         ereport(pg_hint_plan_debug_message_level,
2845                                         (errmsg("hints in comment=\"%s\"",
2846                                                         current_hint_str ? current_hint_str : "(none)"),
2847                                          errhidestmt(msgqno != qno),
2848                                          errhidecontext(msgqno != qno)));
2849                 else
2850                         ereport(pg_hint_plan_debug_message_level,
2851                                         (errmsg("hints in comment=\"%s\", query=\"%s\", debug_query_string=\"%s\"",
2852                                                         current_hint_str ? current_hint_str : "(none)",
2853                                                         query_str ? query_str : "(none)",
2854                                                         debug_query_string ? debug_query_string : "(none)"),
2855                                          errhidestmt(msgqno != qno),
2856                                          errhidecontext(msgqno != qno)));
2857                 msgqno = qno;
2858         }
2859 }
2860
2861 /*
2862  * Read and set up hint information
2863  */
2864 static PlannedStmt *
2865 pg_hint_plan_planner(Query *parse, const char *query_string, int cursorOptions, ParamListInfo boundParams)
2866 {
2867         int                             save_nestlevel;
2868         PlannedStmt        *result;
2869         HintState          *hstate;
2870         const char         *prev_hint_str = NULL;
2871
2872         /*
2873          * Use standard planner if pg_hint_plan is disabled or current nesting
2874          * depth is nesting depth of SPI calls. Other hook functions try to change
2875          * plan with current_hint_state if any, so set it to NULL.
2876          */
2877         if (!pg_hint_plan_enable_hint || hint_inhibit_level > 0)
2878         {
2879                 if (debug_level > 1)
2880                         ereport(pg_hint_plan_debug_message_level,
2881                                         (errmsg ("pg_hint_plan%s: planner: enable_hint=%d,"
2882                                                          " hint_inhibit_level=%d",
2883                                                          qnostr, pg_hint_plan_enable_hint,
2884                                                          hint_inhibit_level),
2885                                          errhidestmt(msgqno != qno)));
2886                 msgqno = qno;
2887
2888                 goto standard_planner_proc;
2889         }
2890
2891         /* always retrieve hint from the top-level query string */
2892         if (plpgsql_recurse_level == 0 && current_hint_str)
2893         {
2894                 pfree((void *)current_hint_str);
2895                 current_hint_str = NULL;
2896         }
2897
2898         get_current_hint_string(parse, query_string);
2899
2900         /* No hint, go the normal way */
2901         if (!current_hint_str)
2902                 goto standard_planner_proc;
2903
2904         /* parse the hint into hint state struct */
2905         hstate = create_hintstate(parse, pstrdup(current_hint_str));
2906
2907         /* run standard planner if we're given with no valid hints */
2908         if (!hstate)
2909         {
2910                 /* forget invalid hint string */
2911                 if (current_hint_str)
2912                 {
2913                         pfree((void *)current_hint_str);
2914                         current_hint_str = NULL;
2915                 }
2916
2917                 goto standard_planner_proc;
2918         }
2919
2920         /*
2921          * Push new hint struct to the hint stack to disable previous hint context.
2922          */
2923         push_hint(hstate);
2924
2925         /*  Set scan enforcement here. */
2926         save_nestlevel = NewGUCNestLevel();
2927
2928         /* Apply Set hints, then save it as the initial state  */
2929         setup_guc_enforcement(current_hint_state->set_hints,
2930                                                    current_hint_state->num_hints[HINT_TYPE_SET],
2931                                                    current_hint_state->context);
2932
2933         current_hint_state->init_scan_mask = get_current_scan_mask();
2934         current_hint_state->init_join_mask = get_current_join_mask();
2935         current_hint_state->init_min_para_tablescan_size =
2936                 min_parallel_table_scan_size;
2937         current_hint_state->init_min_para_indexscan_size =
2938                 min_parallel_index_scan_size;
2939         current_hint_state->init_paratup_cost = parallel_tuple_cost;
2940         current_hint_state->init_parasetup_cost = parallel_setup_cost;
2941
2942         /*
2943          * max_parallel_workers_per_gather should be non-zero here if Workers hint
2944          * is specified.
2945          */
2946         if (max_hint_nworkers > 0 && max_parallel_workers_per_gather < 1)
2947                 set_config_int32_option("max_parallel_workers_per_gather",
2948                                                                 1, current_hint_state->context);
2949         current_hint_state->init_nworkers = max_parallel_workers_per_gather;
2950
2951         if (debug_level > 1)
2952         {
2953                 ereport(pg_hint_plan_debug_message_level,
2954                                 (errhidestmt(msgqno != qno),
2955                                  errmsg("pg_hint_plan%s: planner", qnostr)));
2956                 msgqno = qno;
2957         }
2958
2959         /*
2960          * The planner call below may replace current_hint_str. Store and restore
2961          * it so that the subsequent planning in the upper level doesn't get
2962          * confused.
2963          */
2964         recurse_level++;
2965         prev_hint_str = current_hint_str;
2966         current_hint_str = NULL;
2967
2968         /*
2969          * Use PG_TRY mechanism to recover GUC parameters and current_hint_state to
2970          * the state when this planner started when error occurred in planner.
2971          */
2972         PG_TRY();
2973         {
2974                 if (prev_planner)
2975                         result = (*prev_planner) (parse, query_string,
2976                                                                           cursorOptions, boundParams);
2977                 else
2978                         result = standard_planner(parse, query_string,
2979                                                                           cursorOptions, boundParams);
2980
2981                 current_hint_str = prev_hint_str;
2982                 recurse_level--;
2983         }
2984         PG_CATCH();
2985         {
2986                 /*
2987                  * Rollback changes of GUC parameters, and pop current hint context
2988                  * from hint stack to rewind the state.
2989                  */
2990                 current_hint_str = prev_hint_str;
2991                 recurse_level--;
2992                 AtEOXact_GUC(true, save_nestlevel);
2993                 pop_hint();
2994                 PG_RE_THROW();
2995         }
2996         PG_END_TRY();
2997
2998
2999         /*
3000          * current_hint_str is useless after planning of the top-level query.
3001          */
3002         if (recurse_level < 1 && current_hint_str)
3003         {
3004                 pfree((void *)current_hint_str);
3005                 current_hint_str = NULL;
3006         }
3007
3008         /* Print hint in debug mode. */
3009         if (debug_level == 1)
3010                 HintStateDump(current_hint_state);
3011         else if (debug_level > 1)
3012                 HintStateDump2(current_hint_state);
3013
3014         /*
3015          * Rollback changes of GUC parameters, and pop current hint context from
3016          * hint stack to rewind the state.
3017          */
3018         AtEOXact_GUC(true, save_nestlevel);
3019         pop_hint();
3020
3021         return result;
3022
3023 standard_planner_proc:
3024         if (debug_level > 1)
3025         {
3026                 ereport(pg_hint_plan_debug_message_level,
3027                                 (errhidestmt(msgqno != qno),
3028                                  errmsg("pg_hint_plan%s: planner: no valid hint",
3029                                                 qnostr)));
3030                 msgqno = qno;
3031         }
3032         current_hint_state = NULL;
3033         if (prev_planner)
3034                 result =  (*prev_planner) (parse, query_string,
3035                                                                    cursorOptions, boundParams);
3036         else
3037                 result = standard_planner(parse, query_string,
3038                                                                   cursorOptions, boundParams);
3039
3040         /* The upper-level planner still needs the current hint state */
3041         if (HintStateStack != NIL)
3042                 current_hint_state = (HintState *) lfirst(list_head(HintStateStack));
3043
3044         return result;
3045 }
3046
3047 /*
3048  * Find scan method hint to be applied to the given relation
3049  *
3050  */
3051 static ScanMethodHint *
3052 find_scan_hint(PlannerInfo *root, Index relid)
3053 {
3054         RelOptInfo         *rel;
3055         RangeTblEntry  *rte;
3056         ScanMethodHint  *real_name_hint = NULL;
3057         ScanMethodHint  *alias_hint = NULL;
3058         int                             i;
3059
3060         /* This should not be a join rel */
3061         Assert(relid > 0);
3062         rel = root->simple_rel_array[relid];
3063
3064         /*
3065          * This function is called for any RelOptInfo or its inheritance parent if
3066          * any. If we are called from inheritance planner, the RelOptInfo for the
3067          * parent of target child relation is not set in the planner info.
3068          *
3069          * Otherwise we should check that the reloptinfo is base relation or
3070          * inheritance children.
3071          */
3072         if (rel &&
3073                 rel->reloptkind != RELOPT_BASEREL &&
3074                 rel->reloptkind != RELOPT_OTHER_MEMBER_REL)
3075                 return NULL;
3076
3077         /*
3078          * This is baserel or appendrel children. We can refer to RangeTblEntry.
3079          */
3080         rte = root->simple_rte_array[relid];
3081         Assert(rte);
3082
3083         /* We don't hint on other than relation and foreign tables */
3084         if (rte->rtekind != RTE_RELATION ||
3085                 rte->relkind == RELKIND_FOREIGN_TABLE)
3086                 return NULL;
3087
3088         /* Find scan method hint, which matches given names, from the list. */
3089         for (i = 0; i < current_hint_state->num_hints[HINT_TYPE_SCAN_METHOD]; i++)
3090         {
3091                 ScanMethodHint *hint = current_hint_state->scan_hints[i];
3092
3093                 /* We ignore disabled hints. */
3094                 if (!hint_state_enabled(hint))
3095                         continue;
3096
3097                 if (!alias_hint &&
3098                         RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
3099                         alias_hint = hint;
3100
3101                 /* check the real name for appendrel children */
3102                 if (!real_name_hint &&
3103                         rel && rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
3104                 {
3105                         char *realname = get_rel_name(rte->relid);
3106
3107                         if (realname && RelnameCmp(&realname, &hint->relname) == 0)
3108                                 real_name_hint = hint;
3109                 }
3110
3111                 /* No more match expected, break  */
3112                 if(alias_hint && real_name_hint)
3113                         break;
3114         }
3115
3116         /* real name match precedes alias match */
3117         if (real_name_hint)
3118                 return real_name_hint;
3119
3120         return alias_hint;
3121 }
3122
3123 static ParallelHint *
3124 find_parallel_hint(PlannerInfo *root, Index relid)
3125 {
3126         RelOptInfo         *rel;
3127         RangeTblEntry  *rte;
3128         ParallelHint    *real_name_hint = NULL;
3129         ParallelHint    *alias_hint = NULL;
3130         int                             i;
3131
3132         /* This should not be a join rel */
3133         Assert(relid > 0);
3134         rel = root->simple_rel_array[relid];
3135
3136         /*
3137          * Parallel planning is appliable only on base relation, which has
3138          * RelOptInfo.
3139          */
3140         if (!rel)
3141                 return NULL;
3142
3143         /*
3144          * We have set root->glob->parallelModeOK if needed. What we should do here
3145          * is just following the decision of planner.
3146          */
3147         if (!rel->consider_parallel)
3148                 return NULL;
3149
3150         /*
3151          * This is baserel or appendrel children. We can refer to RangeTblEntry.
3152          */
3153         rte = root->simple_rte_array[relid];
3154         Assert(rte);
3155
3156         /* Find parallel method hint, which matches given names, from the list. */
3157         for (i = 0; i < current_hint_state->num_hints[HINT_TYPE_PARALLEL]; i++)
3158         {
3159                 ParallelHint *hint = current_hint_state->parallel_hints[i];
3160
3161                 /* We ignore disabled hints. */
3162                 if (!hint_state_enabled(hint))
3163                         continue;
3164
3165                 if (!alias_hint &&
3166                         RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
3167                         alias_hint = hint;
3168
3169                 /* check the real name for appendrel children */
3170                 if (!real_name_hint &&
3171                         rel && rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
3172                 {
3173                         char *realname = get_rel_name(rte->relid);
3174
3175                         if (realname && RelnameCmp(&realname, &hint->relname) == 0)
3176                                 real_name_hint = hint;
3177                 }
3178
3179                 /* No more match expected, break  */
3180                 if(alias_hint && real_name_hint)
3181                         break;
3182         }
3183
3184         /* real name match precedes alias match */
3185         if (real_name_hint)
3186                 return real_name_hint;
3187
3188         return alias_hint;
3189 }
3190
3191 /*
3192  * regexeq
3193  *
3194  * Returns TRUE on match, FALSE on no match.
3195  *
3196  *   s1 --- the data to match against
3197  *   s2 --- the pattern
3198  *
3199  * Because we copy s1 to NameData, make the size of s1 less than NAMEDATALEN.
3200  */
3201 static bool
3202 regexpeq(const char *s1, const char *s2)
3203 {
3204         NameData        name;
3205         text       *regexp;
3206         Datum           result;
3207
3208         strcpy(name.data, s1);
3209         regexp = cstring_to_text(s2);
3210
3211         result = DirectFunctionCall2Coll(nameregexeq,
3212                                                                          DEFAULT_COLLATION_OID,
3213                                                                          NameGetDatum(&name),
3214                                                                          PointerGetDatum(regexp));
3215         return DatumGetBool(result);
3216 }
3217
3218
3219 /* Remove indexes instructed not to use by hint. */
3220 static void
3221 restrict_indexes(PlannerInfo *root, ScanMethodHint *hint, RelOptInfo *rel,
3222                            bool using_parent_hint)
3223 {
3224         ListCell           *cell;
3225         ListCell           *next;
3226         StringInfoData  buf;
3227         RangeTblEntry  *rte = root->simple_rte_array[rel->relid];
3228         Oid                             relationObjectId = rte->relid;
3229
3230         /*
3231          * We delete all the IndexOptInfo list and prevent you from being usable by
3232          * a scan.
3233          */
3234         if (hint->enforce_mask == ENABLE_SEQSCAN ||
3235                 hint->enforce_mask == ENABLE_TIDSCAN)
3236         {
3237                 list_free_deep(rel->indexlist);
3238                 rel->indexlist = NIL;
3239                 hint->base.state = HINT_STATE_USED;
3240
3241                 return;
3242         }
3243
3244         /*
3245          * When a list of indexes is not specified, we just use all indexes.
3246          */
3247         if (hint->indexnames == NIL)
3248                 return;
3249
3250         /*
3251          * Leaving only an specified index, we delete it from a IndexOptInfo list
3252          * other than it.
3253          */
3254         if (debug_level > 0)
3255                 initStringInfo(&buf);
3256
3257         for (cell = list_head(rel->indexlist); cell; cell = next)
3258         {
3259                 IndexOptInfo   *info = (IndexOptInfo *) lfirst(cell);
3260                 char               *indexname = get_rel_name(info->indexoid);
3261                 ListCell           *l;
3262                 bool                    use_index = false;
3263
3264                 next = lnext(rel->indexlist, cell);
3265                 foreach(l, hint->indexnames)
3266                 {
3267                         char   *hintname = (char *) lfirst(l);
3268                         bool    result;
3269
3270                         if (hint->regexp)
3271                                 result = regexpeq(indexname, hintname);
3272                         else
3273                                 result = RelnameCmp(&indexname, &hintname) == 0;
3274
3275                         if (result)
3276                         {
3277                                 use_index = true;
3278                                 if (debug_level > 0)
3279                                 {
3280                                         appendStringInfoCharMacro(&buf, ' ');
3281                                         quote_value(&buf, indexname);
3282                                 }
3283
3284                                 break;
3285                         }
3286                 }
3287
3288                 /*
3289                  * Apply index restriction of parent hint to children. Since index
3290                  * inheritance is not explicitly described we should search for an
3291                  * children's index with the same definition to that of the parent.
3292                  */
3293                 if (using_parent_hint && !use_index)
3294                 {
3295                         foreach(l, current_hint_state->parent_index_infos)
3296                         {
3297                                 int                                     i;
3298                                 HeapTuple                       ht_idx;
3299                                 ParentIndexInfo    *p_info = (ParentIndexInfo *)lfirst(l);
3300
3301                                 /*
3302                                  * we check the 'same' index by comparing uniqueness, access
3303                                  * method and index key columns.
3304                                  */
3305                                 if (p_info->indisunique != info->unique ||
3306                                         p_info->method != info->relam ||
3307                                         list_length(p_info->column_names) != info->ncolumns)
3308                                         continue;
3309
3310                                 /* Check if index key columns match */
3311                                 for (i = 0; i < info->ncolumns; i++)
3312                                 {
3313                                         char       *c_attname = NULL;
3314                                         char       *p_attname = NULL;
3315
3316                                         p_attname = list_nth(p_info->column_names, i);
3317
3318                                         /*
3319                                          * if both of the key of the same position are expressions,
3320                                          * ignore them for now and check later.
3321                                          */
3322                                         if (info->indexkeys[i] == 0 && !p_attname)
3323                                                 continue;
3324
3325                                         /* deny if one is expression while another is not */
3326                                         if (info->indexkeys[i] == 0 || !p_attname)
3327                                                 break;
3328
3329                                         c_attname = get_attname(relationObjectId,
3330                                                                                         info->indexkeys[i], false);
3331
3332                                         /* deny if any of column attributes don't match */
3333                                         if (strcmp(p_attname, c_attname) != 0 ||
3334                                                 p_info->indcollation[i] != info->indexcollations[i] ||
3335                                                 p_info->opclass[i] != info->opcintype[i]||
3336                                                 ((p_info->indoption[i] & INDOPTION_DESC) != 0)
3337                                                 != info->reverse_sort[i] ||
3338                                                 ((p_info->indoption[i] & INDOPTION_NULLS_FIRST) != 0)
3339                                                 != info->nulls_first[i])
3340                                                 break;
3341                                 }
3342
3343                                 /* deny this if any difference found */
3344                                 if (i != info->ncolumns)
3345                                         continue;
3346
3347                                 /* check on key expressions  */
3348                                 if ((p_info->expression_str && (info->indexprs != NIL)) ||
3349                                         (p_info->indpred_str && (info->indpred != NIL)))
3350                                 {
3351                                         /* fetch the index of this child */
3352                                         ht_idx = SearchSysCache1(INDEXRELID,
3353                                                                                          ObjectIdGetDatum(info->indexoid));
3354
3355                                         /* check expressions if both expressions are available */
3356                                         if (p_info->expression_str &&
3357                                                 !heap_attisnull(ht_idx, Anum_pg_index_indexprs, NULL))
3358                                         {
3359                                                 Datum       exprsDatum;
3360                                                 bool        isnull;
3361                                                 Datum       result;
3362
3363                                                 /*
3364                                                  * to change the expression's parameter of child's
3365                                                  * index to strings
3366                                                  */
3367                                                 exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
3368                                                                                                          Anum_pg_index_indexprs,
3369                                                                                                          &isnull);
3370
3371                                                 result = DirectFunctionCall2(pg_get_expr,
3372                                                                                                          exprsDatum,
3373                                                                                                          ObjectIdGetDatum(
3374                                                                                                                  relationObjectId));
3375
3376                                                 /* deny if expressions don't match */
3377                                                 if (strcmp(p_info->expression_str,
3378                                                                    text_to_cstring(DatumGetTextP(result))) != 0)
3379                                                 {
3380                                                         /* Clean up */
3381                                                         ReleaseSysCache(ht_idx);
3382                                                         continue;
3383                                                 }
3384                                         }
3385
3386                                         /* compare index predicates  */
3387                                         if (p_info->indpred_str &&
3388                                                 !heap_attisnull(ht_idx, Anum_pg_index_indpred, NULL))
3389                                         {
3390                                                 Datum       predDatum;
3391                                                 bool        isnull;
3392                                                 Datum       result;
3393
3394                                                 predDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
3395                                                                                                          Anum_pg_index_indpred,
3396                                                                                                          &isnull);
3397
3398                                                 result = DirectFunctionCall2(pg_get_expr,
3399                                                                                                          predDatum,
3400                                                                                                          ObjectIdGetDatum(
3401                                                                                                                  relationObjectId));
3402
3403                                                 if (strcmp(p_info->indpred_str,
3404                                                                    text_to_cstring(DatumGetTextP(result))) != 0)
3405                                                 {
3406                                                         /* Clean up */
3407                                                         ReleaseSysCache(ht_idx);
3408                                                         continue;
3409                                                 }
3410                                         }
3411
3412                                         /* Clean up */
3413                                         ReleaseSysCache(ht_idx);
3414                                 }
3415                                 else if (p_info->expression_str || (info->indexprs != NIL))
3416                                         continue;
3417                                 else if (p_info->indpred_str || (info->indpred != NIL))
3418                                         continue;
3419
3420                                 use_index = true;
3421
3422                                 /* to log the candidate of index */
3423                                 if (debug_level > 0)
3424                                 {
3425                                         appendStringInfoCharMacro(&buf, ' ');
3426                                         quote_value(&buf, indexname);
3427                                 }
3428
3429                                 break;
3430                         }
3431                 }
3432
3433                 if (!use_index)
3434                 {
3435                         rel->indexlist = list_delete_cell(rel->indexlist, cell);
3436
3437                         /*
3438                          * The cells after the deleted cell have been moved towards the
3439                          * list head by 1 element.  the next iteration should visit the
3440                          * cell at the same address if any.
3441                          */
3442                         if (next)
3443                                 next = cell;
3444                 }
3445
3446                 pfree(indexname);
3447         }
3448
3449         if (debug_level == 1)
3450         {
3451                 StringInfoData  rel_buf;
3452                 char *disprelname = "";
3453
3454                 /*
3455                  * If this hint targetted the parent, use the real name of this
3456                  * child. Otherwise use hint specification.
3457                  */
3458                 if (using_parent_hint)
3459                         disprelname = get_rel_name(rte->relid);
3460                 else
3461                         disprelname = hint->relname;
3462
3463
3464                 initStringInfo(&rel_buf);
3465                 quote_value(&rel_buf, disprelname);
3466
3467                 ereport(pg_hint_plan_debug_message_level,
3468                                 (errmsg("available indexes for %s(%s):%s",
3469                                          hint->base.keyword,
3470                                          rel_buf.data,
3471                                          buf.data)));
3472                 pfree(buf.data);
3473                 pfree(rel_buf.data);
3474         }
3475 }
3476
3477 /*
3478  * Return information of index definition.
3479  */
3480 static ParentIndexInfo *
3481 get_parent_index_info(Oid indexoid, Oid relid)
3482 {
3483         ParentIndexInfo *p_info = palloc(sizeof(ParentIndexInfo));
3484         Relation            indexRelation;
3485         Form_pg_index   index;
3486         char               *attname;
3487         int                             i;
3488
3489         indexRelation = index_open(indexoid, RowExclusiveLock);
3490
3491         index = indexRelation->rd_index;
3492
3493         p_info->indisunique = index->indisunique;
3494         p_info->method = indexRelation->rd_rel->relam;
3495
3496         p_info->column_names = NIL;
3497         p_info->indcollation = (Oid *) palloc(sizeof(Oid) * index->indnatts);
3498         p_info->opclass = (Oid *) palloc(sizeof(Oid) * index->indnatts);
3499         p_info->indoption = (int16 *) palloc(sizeof(Oid) * index->indnatts);
3500
3501         /*
3502          * Collect relation attribute names of index columns for index
3503          * identification, not index attribute names. NULL means expression index
3504          * columns.
3505          */
3506         for (i = 0; i < index->indnatts; i++)
3507         {
3508                 attname = get_attname(relid, index->indkey.values[i], true);
3509                 p_info->column_names = lappend(p_info->column_names, attname);
3510
3511                 p_info->indcollation[i] = indexRelation->rd_indcollation[i];
3512                 p_info->opclass[i] = indexRelation->rd_opcintype[i];
3513                 p_info->indoption[i] = indexRelation->rd_indoption[i];
3514         }
3515
3516         /*
3517          * to check to match the expression's parameter of index with child indexes
3518          */
3519         p_info->expression_str = NULL;
3520         if(!heap_attisnull(indexRelation->rd_indextuple, Anum_pg_index_indexprs,
3521                                            NULL))
3522         {
3523                 Datum       exprsDatum;
3524                 bool            isnull;
3525                 Datum           result;
3526
3527                 exprsDatum = SysCacheGetAttr(INDEXRELID, indexRelation->rd_indextuple,
3528                                                                          Anum_pg_index_indexprs, &isnull);
3529
3530                 result = DirectFunctionCall2(pg_get_expr,
3531                                                                          exprsDatum,
3532                                                                          ObjectIdGetDatum(relid));
3533
3534                 p_info->expression_str = text_to_cstring(DatumGetTextP(result));
3535         }
3536
3537         /*
3538          * to check to match the predicate's parameter of index with child indexes
3539          */
3540         p_info->indpred_str = NULL;
3541         if(!heap_attisnull(indexRelation->rd_indextuple, Anum_pg_index_indpred,
3542                                            NULL))
3543         {
3544                 Datum       predDatum;
3545                 bool            isnull;
3546                 Datum           result;
3547
3548                 predDatum = SysCacheGetAttr(INDEXRELID, indexRelation->rd_indextuple,
3549                                                                          Anum_pg_index_indpred, &isnull);
3550
3551                 result = DirectFunctionCall2(pg_get_expr,
3552                                                                          predDatum,
3553                                                                          ObjectIdGetDatum(relid));
3554
3555                 p_info->indpred_str = text_to_cstring(DatumGetTextP(result));
3556         }
3557
3558         index_close(indexRelation, NoLock);
3559
3560         return p_info;
3561 }
3562
3563 /*
3564  * cancel hint enforcement
3565  */
3566 static void
3567 reset_hint_enforcement()
3568 {
3569         setup_scan_method_enforcement(NULL, current_hint_state);
3570         setup_parallel_plan_enforcement(NULL, current_hint_state);
3571 }
3572
3573 /*
3574  * Set planner guc parameters according to corresponding scan hints.  Returns
3575  * bitmap of HintTypeBitmap. If shint or phint is not NULL, set used hint
3576  * there respectively.
3577  */
3578 static int
3579 setup_hint_enforcement(PlannerInfo *root, RelOptInfo *rel,
3580                                            ScanMethodHint **rshint, ParallelHint **rphint)
3581 {
3582         Index   new_parent_relid = 0;
3583         ListCell *l;
3584         ScanMethodHint *shint = NULL;
3585         ParallelHint   *phint = NULL;
3586         bool                    inhparent = root->simple_rte_array[rel->relid]->inh;
3587         Oid             relationObjectId = root->simple_rte_array[rel->relid]->relid;
3588         int                             ret = 0;
3589
3590         /* reset returns if requested  */
3591         if (rshint != NULL) *rshint = NULL;
3592         if (rphint != NULL) *rphint = NULL;
3593
3594         /*
3595          * We could register the parent relation of the following children here
3596          * when inhparent == true but inheritnce planner doesn't call this function
3597          * for parents. Since we cannot distinguish who called this function we
3598          * cannot do other than always seeking the parent regardless of who called
3599          * this function.
3600          */
3601         if (inhparent)
3602         {
3603                 /* set up only parallel hints for parent relation */
3604                 phint = find_parallel_hint(root, rel->relid);
3605                 if (phint)
3606                 {
3607                         setup_parallel_plan_enforcement(phint, current_hint_state);
3608                         if (rphint) *rphint = phint;
3609                         ret |= HINT_BM_PARALLEL;
3610                         return ret;
3611                 }
3612
3613                 if (debug_level > 1)
3614                         ereport(pg_hint_plan_debug_message_level,
3615                                         (errhidestmt(true),
3616                                          errmsg ("pg_hint_plan%s: setup_hint_enforcement"
3617                                                          " skipping inh parent: relation=%u(%s), inhparent=%d,"
3618                                                          " current_hint_state=%p, hint_inhibit_level=%d",
3619                                                          qnostr, relationObjectId,
3620                                                          get_rel_name(relationObjectId),
3621                                                          inhparent, current_hint_state, hint_inhibit_level)));
3622                 return 0;
3623         }
3624
3625         if (bms_num_members(rel->top_parent_relids) == 1)
3626         {
3627                 new_parent_relid = bms_next_member(rel->top_parent_relids, -1);
3628                 current_hint_state->current_root = root;
3629                 Assert(new_parent_relid > 0);
3630         }
3631         else
3632         {
3633                 /* This relation doesn't have a parent. Cancel current_hint_state. */
3634                 current_hint_state->parent_relid = 0;
3635                 current_hint_state->parent_scan_hint = NULL;
3636                 current_hint_state->parent_parallel_hint = NULL;
3637         }
3638
3639         if (new_parent_relid > 0)
3640         {
3641                 /*
3642                  * Here we found a new parent for the current relation. Scan continues
3643                  * hint to other childrens of this parent so remember it to avoid
3644                  * redundant setup cost.
3645                  */
3646                 current_hint_state->parent_relid = new_parent_relid;
3647
3648                 /* Find hints for the parent */
3649                 current_hint_state->parent_scan_hint =
3650                         find_scan_hint(root, current_hint_state->parent_relid);
3651
3652                 current_hint_state->parent_parallel_hint =
3653                         find_parallel_hint(root, current_hint_state->parent_relid);
3654
3655                 /*
3656                  * If hint is found for the parent, apply it for this child instead
3657                  * of its own.
3658                  */
3659                 if (current_hint_state->parent_scan_hint)
3660                 {
3661                         ScanMethodHint * pshint = current_hint_state->parent_scan_hint;
3662
3663                         pshint->base.state = HINT_STATE_USED;
3664
3665                         /* Apply index mask in the same manner to the parent. */
3666                         if (pshint->indexnames)
3667                         {
3668                                 Oid                     parentrel_oid;
3669                                 Relation        parent_rel;
3670
3671                                 parentrel_oid =
3672                                         root->simple_rte_array[current_hint_state->parent_relid]->relid;
3673                                 parent_rel = table_open(parentrel_oid, NoLock);
3674
3675                                 /* Search the parent relation for indexes match the hint spec */
3676                                 foreach(l, RelationGetIndexList(parent_rel))
3677                                 {
3678                                         Oid         indexoid = lfirst_oid(l);
3679                                         char       *indexname = get_rel_name(indexoid);
3680                                         ListCell   *lc;
3681                                         ParentIndexInfo *parent_index_info;
3682
3683                                         foreach(lc, pshint->indexnames)
3684                                         {
3685                                                 if (RelnameCmp(&indexname, &lfirst(lc)) == 0)
3686                                                         break;
3687                                         }
3688                                         if (!lc)
3689                                                 continue;
3690
3691                                         parent_index_info =
3692                                                 get_parent_index_info(indexoid, parentrel_oid);
3693                                         current_hint_state->parent_index_infos =
3694                                                 lappend(current_hint_state->parent_index_infos,
3695                                                                 parent_index_info);
3696                                 }
3697                                 table_close(parent_rel, NoLock);
3698                         }
3699                 }
3700         }
3701
3702         shint = find_scan_hint(root, rel->relid);
3703         if (!shint)
3704                 shint = current_hint_state->parent_scan_hint;
3705
3706         if (shint)
3707         {
3708                 bool using_parent_hint =
3709                         (shint == current_hint_state->parent_scan_hint);
3710
3711                 ret |= HINT_BM_SCAN_METHOD;
3712
3713                 /* Setup scan enforcement environment */
3714                 setup_scan_method_enforcement(shint, current_hint_state);
3715
3716                 /* restrict unwanted inexes */
3717                 restrict_indexes(root, shint, rel, using_parent_hint);
3718
3719                 if (debug_level > 1)
3720                 {
3721                         char *additional_message = "";
3722
3723                         if (shint == current_hint_state->parent_scan_hint)
3724                                 additional_message = " by parent hint";
3725
3726                         ereport(pg_hint_plan_debug_message_level,
3727                                         (errhidestmt(true),
3728                                          errmsg ("pg_hint_plan%s: setup_hint_enforcement"
3729                                                          " index deletion%s:"
3730                                                          " relation=%u(%s), inhparent=%d, "
3731                                                          "current_hint_state=%p,"
3732                                                          " hint_inhibit_level=%d, scanmask=0x%x",
3733                                                          qnostr, additional_message,
3734                                                          relationObjectId,
3735                                                          get_rel_name(relationObjectId),
3736                                                          inhparent, current_hint_state,
3737                                                          hint_inhibit_level,
3738                                                          shint->enforce_mask)));
3739                 }
3740         }
3741
3742         /* Do the same for parallel plan enforcement */
3743         phint = find_parallel_hint(root, rel->relid);
3744         if (!phint)
3745                 phint = current_hint_state->parent_parallel_hint;
3746
3747         setup_parallel_plan_enforcement(phint, current_hint_state);
3748
3749         if (phint)
3750                 ret |= HINT_BM_PARALLEL;
3751
3752         /* Nothing to apply. Reset the scan mask to intial state */
3753         if (!shint && ! phint)
3754         {
3755                 if (debug_level > 1)
3756                         ereport(pg_hint_plan_debug_message_level,
3757                                         (errhidestmt (true),
3758                                          errmsg ("pg_hint_plan%s: setup_hint_enforcement"
3759                                                          " no hint applied:"
3760                                                          " relation=%u(%s), inhparent=%d, current_hint=%p,"
3761                                                          " hint_inhibit_level=%d, scanmask=0x%x",
3762                                                          qnostr, relationObjectId,
3763                                                          get_rel_name(relationObjectId),
3764                                                          inhparent, current_hint_state, hint_inhibit_level,
3765                                                          current_hint_state->init_scan_mask)));
3766
3767                 setup_scan_method_enforcement(NULL,     current_hint_state);
3768
3769                 return ret;
3770         }
3771
3772         if (rshint != NULL) *rshint = shint;
3773         if (rphint != NULL) *rphint = phint;
3774
3775         return ret;
3776 }
3777
3778 /*
3779  * Return index of relation which matches given aliasname, or 0 if not found.
3780  * If same aliasname was used multiple times in a query, return -1.
3781  */
3782 static int
3783 find_relid_aliasname(PlannerInfo *root, char *aliasname, List *initial_rels,
3784                                          const char *str)
3785 {
3786         int             i;
3787         Index   found = 0;
3788
3789         for (i = 1; i < root->simple_rel_array_size; i++)
3790         {
3791                 ListCell   *l;
3792
3793                 if (root->simple_rel_array[i] == NULL)
3794                         continue;
3795
3796                 Assert(i == root->simple_rel_array[i]->relid);
3797
3798                 if (RelnameCmp(&aliasname,
3799                                            &root->simple_rte_array[i]->eref->aliasname) != 0)
3800                         continue;
3801
3802                 foreach(l, initial_rels)
3803                 {
3804                         RelOptInfo *rel = (RelOptInfo *) lfirst(l);
3805
3806                         if (rel->reloptkind == RELOPT_BASEREL)
3807                         {
3808                                 if (rel->relid != i)
3809                                         continue;
3810                         }
3811                         else
3812                         {
3813                                 Assert(rel->reloptkind == RELOPT_JOINREL);
3814
3815                                 if (!bms_is_member(i, rel->relids))
3816                                         continue;
3817                         }
3818
3819                         if (found != 0)
3820                         {
3821                                 hint_ereport(str,
3822                                                          ("Relation name \"%s\" is ambiguous.",
3823                                                           aliasname));
3824                                 return -1;
3825                         }
3826
3827                         found = i;
3828                         break;
3829                 }
3830
3831         }
3832
3833         return found;
3834 }
3835
3836 /*
3837  * Return join hint which matches given joinrelids.
3838  */
3839 static JoinMethodHint *
3840 find_join_hint(Relids joinrelids)
3841 {
3842         List       *join_hint;
3843         ListCell   *l;
3844
3845         join_hint = current_hint_state->join_hint_level[bms_num_members(joinrelids)];
3846
3847         foreach(l, join_hint)
3848         {
3849                 JoinMethodHint *hint = (JoinMethodHint *) lfirst(l);
3850
3851                 if (bms_equal(joinrelids, hint->joinrelids))
3852                         return hint;
3853         }
3854
3855         return NULL;
3856 }
3857
3858
3859 /*
3860  * Return memoize hint which matches given joinrelids.
3861  */
3862 static JoinMethodHint *
3863 find_memoize_hint(Relids joinrelids)
3864 {
3865         List       *join_hint;
3866         ListCell   *l;
3867
3868         join_hint = current_hint_state->memoize_hint_level[bms_num_members(joinrelids)];
3869
3870         foreach(l, join_hint)
3871         {
3872                 JoinMethodHint *hint = (JoinMethodHint *) lfirst(l);
3873
3874                 if (bms_equal(joinrelids, hint->joinrelids))
3875                         return hint;
3876         }
3877
3878         return NULL;
3879 }
3880
3881
3882 static Relids
3883 OuterInnerJoinCreate(OuterInnerRels *outer_inner, LeadingHint *leading_hint,
3884         PlannerInfo *root, List *initial_rels, HintState *hstate, int nbaserel)
3885 {
3886         OuterInnerRels *outer_rels;
3887         OuterInnerRels *inner_rels;
3888         Relids                  outer_relids;
3889         Relids                  inner_relids;
3890         Relids                  join_relids;
3891         JoinMethodHint *hint;
3892
3893         if (outer_inner->relation != NULL)
3894         {
3895                 return bms_make_singleton(
3896                                         find_relid_aliasname(root, outer_inner->relation,
3897                                                                                  initial_rels,
3898                                                                                  leading_hint->base.hint_str));
3899         }
3900
3901         outer_rels = linitial(outer_inner->outer_inner_pair);
3902         inner_rels = llast(outer_inner->outer_inner_pair);
3903
3904         outer_relids = OuterInnerJoinCreate(outer_rels,
3905                                                                                 leading_hint,
3906                                                                                 root,
3907                                                                                 initial_rels,
3908                                                                                 hstate,
3909                                                                                 nbaserel);
3910         inner_relids = OuterInnerJoinCreate(inner_rels,
3911                                                                                 leading_hint,
3912                                                                                 root,
3913                                                                                 initial_rels,
3914                                                                                 hstate,
3915                                                                                 nbaserel);
3916
3917         join_relids = bms_add_members(outer_relids, inner_relids);
3918
3919         if (bms_num_members(join_relids) > nbaserel)
3920                 return join_relids;
3921
3922         /*
3923          * If we don't have join method hint, create new one for the
3924          * join combination with all join methods are enabled.
3925          */
3926         hint = find_join_hint(join_relids);
3927         if (hint == NULL)
3928         {
3929                 /*
3930                  * Here relnames is not set, since Relids bitmap is sufficient to
3931                  * control paths of this query afterward.
3932                  */
3933                 hint = (JoinMethodHint *) JoinMethodHintCreate(
3934                                         leading_hint->base.hint_str,
3935                                         HINT_LEADING,
3936                                         HINT_KEYWORD_LEADING);
3937                 hint->base.state = HINT_STATE_USED;
3938                 hint->nrels = bms_num_members(join_relids);
3939                 hint->enforce_mask = ENABLE_ALL_JOIN;
3940                 hint->joinrelids = bms_copy(join_relids);
3941                 hint->inner_nrels = bms_num_members(inner_relids);
3942                 hint->inner_joinrelids = bms_copy(inner_relids);
3943
3944                 hstate->join_hint_level[hint->nrels] =
3945                         lappend(hstate->join_hint_level[hint->nrels], hint);
3946         }
3947         else
3948         {
3949                 hint->inner_nrels = bms_num_members(inner_relids);
3950                 hint->inner_joinrelids = bms_copy(inner_relids);
3951         }
3952
3953         return join_relids;
3954 }
3955
3956 static Relids
3957 create_bms_of_relids(Hint *base, PlannerInfo *root, List *initial_rels,
3958                 int nrels, char **relnames)
3959 {
3960         int             relid;
3961         Relids  relids = NULL;
3962         int             j;
3963         char   *relname;
3964
3965         for (j = 0; j < nrels; j++)
3966         {
3967                 relname = relnames[j];
3968
3969                 relid = find_relid_aliasname(root, relname, initial_rels,
3970                                                                          base->hint_str);
3971
3972                 if (relid == -1)
3973                         base->state = HINT_STATE_ERROR;
3974
3975                 /*
3976                  * the aliasname is not found(relid == 0) or same aliasname was used
3977                  * multiple times in a query(relid == -1)
3978                  */
3979                 if (relid <= 0)
3980                 {
3981                         relids = NULL;
3982                         break;
3983                 }
3984                 if (bms_is_member(relid, relids))
3985                 {
3986                         hint_ereport(base->hint_str,
3987                                                  ("Relation name \"%s\" is duplicated.", relname));
3988                         base->state = HINT_STATE_ERROR;
3989                         break;
3990                 }
3991
3992                 relids = bms_add_member(relids, relid);
3993         }
3994         return relids;
3995 }
3996 /*
3997  * Transform join method hint into handy form.
3998  *
3999  *   - create bitmap of relids from alias names, to make it easier to check
4000  *     whether a join path matches a join method hint.
4001  *   - add join method hints which are necessary to enforce join order
4002  *     specified by Leading hint
4003  */
4004 static bool
4005 transform_join_hints(HintState *hstate, PlannerInfo *root, int nbaserel,
4006                 List *initial_rels, JoinMethodHint **join_method_hints)
4007 {
4008         int                             i;
4009         int                             relid;
4010         Relids                  joinrelids;
4011         int                             njoinrels;
4012         ListCell           *l;
4013         char               *relname;
4014         LeadingHint        *lhint = NULL;
4015
4016         /*
4017          * Create bitmap of relids from alias names for each join method hint.
4018          * Bitmaps are more handy than strings in join searching.
4019          */
4020         for (i = 0; i < hstate->num_hints[HINT_TYPE_JOIN_METHOD]; i++)
4021         {
4022                 JoinMethodHint *hint = hstate->join_hints[i];
4023
4024                 if (!hint_state_enabled(hint) || hint->nrels > nbaserel)
4025                         continue;
4026
4027                 hint->joinrelids = create_bms_of_relids(&(hint->base), root,
4028                                                                          initial_rels, hint->nrels, hint->relnames);
4029
4030                 if (hint->joinrelids == NULL || hint->base.state == HINT_STATE_ERROR)
4031                         continue;
4032
4033                 hstate->join_hint_level[hint->nrels] =
4034                         lappend(hstate->join_hint_level[hint->nrels], hint);
4035         }
4036
4037         /* ditto for memoize hints */
4038         for (i = 0; i < hstate->num_hints[HINT_TYPE_MEMOIZE]; i++)
4039         {
4040                 JoinMethodHint *hint = hstate->join_hints[i];
4041
4042                 if (!hint_state_enabled(hint) || hint->nrels > nbaserel)
4043                         continue;
4044
4045                 hint->joinrelids = create_bms_of_relids(&(hint->base), root,
4046                                                                          initial_rels, hint->nrels, hint->relnames);
4047
4048                 if (hint->joinrelids == NULL || hint->base.state == HINT_STATE_ERROR)
4049                         continue;
4050
4051                 hstate->memoize_hint_level[hint->nrels] =
4052                         lappend(hstate->memoize_hint_level[hint->nrels], hint);
4053         }
4054
4055         /*
4056          * Create bitmap of relids from alias names for each rows hint.
4057          * Bitmaps are more handy than strings in join searching.
4058          */
4059         for (i = 0; i < hstate->num_hints[HINT_TYPE_ROWS]; i++)
4060         {
4061                 RowsHint *hint = hstate->rows_hints[i];
4062
4063                 if (!hint_state_enabled(hint) || hint->nrels > nbaserel)
4064                         continue;
4065
4066                 hint->joinrelids = create_bms_of_relids(&(hint->base), root,
4067                                                                          initial_rels, hint->nrels, hint->relnames);
4068         }
4069
4070         /* Do nothing if no Leading hint was supplied. */
4071         if (hstate->num_hints[HINT_TYPE_LEADING] == 0)
4072                 return false;
4073
4074         /*
4075          * Decide whether to use Leading hint
4076          */
4077         for (i = 0; i < hstate->num_hints[HINT_TYPE_LEADING]; i++)
4078         {
4079                 LeadingHint        *leading_hint = (LeadingHint *)hstate->leading_hint[i];
4080                 Relids                  relids;
4081
4082                 if (leading_hint->base.state == HINT_STATE_ERROR)
4083                         continue;
4084
4085                 relid = 0;
4086                 relids = NULL;
4087
4088                 foreach(l, leading_hint->relations)
4089                 {
4090                         relname = (char *)lfirst(l);;
4091
4092                         relid = find_relid_aliasname(root, relname, initial_rels,
4093                                                                                  leading_hint->base.hint_str);
4094                         if (relid == -1)
4095                                 leading_hint->base.state = HINT_STATE_ERROR;
4096
4097                         if (relid <= 0)
4098                                 break;
4099
4100                         if (bms_is_member(relid, relids))
4101                         {
4102                                 hint_ereport(leading_hint->base.hint_str,
4103                                                          ("Relation name \"%s\" is duplicated.", relname));
4104                                 leading_hint->base.state = HINT_STATE_ERROR;
4105                                 break;
4106                         }
4107
4108                         relids = bms_add_member(relids, relid);
4109                 }
4110
4111                 if (relid <= 0 || leading_hint->base.state == HINT_STATE_ERROR)
4112                         continue;
4113
4114                 if (lhint != NULL)
4115                 {
4116                         hint_ereport(lhint->base.hint_str,
4117                                  ("Conflict %s hint.", HintTypeName[lhint->base.type]));
4118                         lhint->base.state = HINT_STATE_DUPLICATION;
4119                 }
4120                 leading_hint->base.state = HINT_STATE_USED;
4121                 lhint = leading_hint;
4122         }
4123
4124         /* check to exist Leading hint marked with 'used'. */
4125         if (lhint == NULL)
4126                 return false;
4127
4128         /*
4129          * We need join method hints which fit specified join order in every join
4130          * level.  For example, Leading(A B C) virtually requires following join
4131          * method hints, if no join method hint supplied:
4132          *   - level 1: none
4133          *   - level 2: NestLoop(A B), MergeJoin(A B), HashJoin(A B)
4134          *   - level 3: NestLoop(A B C), MergeJoin(A B C), HashJoin(A B C)
4135          *
4136          * If we already have join method hint which fits specified join order in
4137          * that join level, we leave it as-is and don't add new hints.
4138          */
4139         joinrelids = NULL;
4140         njoinrels = 0;
4141         if (lhint->outer_inner == NULL)
4142         {
4143                 foreach(l, lhint->relations)
4144                 {
4145                         JoinMethodHint *hint;
4146
4147                         relname = (char *)lfirst(l);
4148
4149                         /*
4150                          * Find relid of the relation which has given name.  If we have the
4151                          * name given in Leading hint multiple times in the join, nothing to
4152                          * do.
4153                          */
4154                         relid = find_relid_aliasname(root, relname, initial_rels,
4155                                                                                  hstate->hint_str);
4156
4157                         /* Create bitmap of relids for current join level. */
4158                         joinrelids = bms_add_member(joinrelids, relid);
4159                         njoinrels++;
4160
4161                         /* We never have join method hint for single relation. */
4162                         if (njoinrels < 2)
4163                                 continue;
4164
4165                         /*
4166                          * If we don't have join method hint, create new one for the
4167                          * join combination with all join methods are enabled.
4168                          */
4169                         hint = find_join_hint(joinrelids);
4170                         if (hint == NULL)
4171                         {
4172                                 /*
4173                                  * Here relnames is not set, since Relids bitmap is sufficient
4174                                  * to control paths of this query afterward.
4175                                  */
4176                                 hint = (JoinMethodHint *) JoinMethodHintCreate(
4177                                                                                         lhint->base.hint_str,
4178                                                                                         HINT_LEADING,
4179                                                                                         HINT_KEYWORD_LEADING);
4180                                 hint->base.state = HINT_STATE_USED;
4181                                 hint->nrels = njoinrels;
4182                                 hint->enforce_mask = ENABLE_ALL_JOIN;
4183                                 hint->joinrelids = bms_copy(joinrelids);
4184                         }
4185
4186                         join_method_hints[njoinrels] = hint;
4187
4188                         if (njoinrels >= nbaserel)
4189                                 break;
4190                 }
4191                 bms_free(joinrelids);
4192
4193                 if (njoinrels < 2)
4194                         return false;
4195
4196                 /*
4197                  * Delete all join hints which have different combination from Leading
4198                  * hint.
4199                  */
4200                 for (i = 2; i <= njoinrels; i++)
4201                 {
4202                         list_free(hstate->join_hint_level[i]);
4203
4204                         hstate->join_hint_level[i] = lappend(NIL, join_method_hints[i]);
4205                 }
4206         }
4207         else
4208         {
4209                 joinrelids = OuterInnerJoinCreate(lhint->outer_inner,
4210                                                                                   lhint,
4211                                           root,
4212                                           initial_rels,
4213                                                                                   hstate,
4214                                                                                   nbaserel);
4215
4216                 njoinrels = bms_num_members(joinrelids);
4217                 Assert(njoinrels >= 2);
4218
4219                 /*
4220                  * Delete all join hints which have different combination from Leading
4221                  * hint.
4222                  */
4223                 for (i = 2;i <= njoinrels; i++)
4224                 {
4225                         if (hstate->join_hint_level[i] != NIL)
4226                         {
4227                                 ListCell *next = NULL;
4228                                 for(l = list_head(hstate->join_hint_level[i]); l; l = next)
4229                                 {
4230
4231                                         JoinMethodHint *hint = (JoinMethodHint *)lfirst(l);
4232
4233                                         next = lnext(hstate->join_hint_level[i], l);
4234
4235                                         if (hint->inner_nrels == 0 &&
4236                                                 !(bms_intersect(hint->joinrelids, joinrelids) == NULL ||
4237                                                   bms_equal(bms_union(hint->joinrelids, joinrelids),
4238                                                   hint->joinrelids)))
4239                                         {
4240                                                 hstate->join_hint_level[i] =
4241                                                         list_delete_cell(hstate->join_hint_level[i], l);
4242                                                 /*
4243                                                  * The cells after the deleted cell have been moved
4244                                                  * towards the list head by 1 element.  the next
4245                                                  * iteration should visit the cell at the same address
4246                                                  * if any.
4247                                                  */
4248                                                 if (next)
4249                                                         next = l;
4250                                         }
4251                                 }
4252                         }
4253                 }
4254
4255                 bms_free(joinrelids);
4256         }
4257
4258         if (hint_state_enabled(lhint))
4259         {
4260                 set_join_config_options(DISABLE_ALL_JOIN, false,
4261                                                                 current_hint_state->context);
4262                 return true;
4263         }
4264         return false;
4265 }
4266
4267 /*
4268  * wrapper of make_join_rel()
4269  *
4270  * call make_join_rel() after changing enable_* parameters according to given
4271  * hints.
4272  */
4273 static RelOptInfo *
4274 make_join_rel_wrapper(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
4275 {
4276         Relids                  joinrelids;
4277         JoinMethodHint *join_hint;
4278         JoinMethodHint *memoize_hint;
4279         RelOptInfo         *rel;
4280         int                             save_nestlevel;
4281
4282         joinrelids = bms_union(rel1->relids, rel2->relids);
4283         join_hint = find_join_hint(joinrelids);
4284         memoize_hint = find_memoize_hint(joinrelids);
4285         bms_free(joinrelids);
4286
4287         /* reject non-matching hints */
4288         if (join_hint && join_hint->inner_nrels != 0)
4289                 join_hint = NULL;
4290
4291         if (memoize_hint && memoize_hint->inner_nrels != 0)
4292                 memoize_hint = NULL;
4293
4294         if (join_hint || memoize_hint)
4295         {
4296                 save_nestlevel = NewGUCNestLevel();
4297
4298                 if (join_hint)
4299                         set_join_config_options(join_hint->enforce_mask, false,
4300                                                                         current_hint_state->context);
4301
4302                 if (memoize_hint)
4303                 {
4304                         bool memoize =
4305                                 memoize_hint->base.hint_keyword == HINT_KEYWORD_MEMOIZE;
4306                         set_config_option_noerror("enable_memoize",
4307                                                                           memoize ? "true" : "false",
4308                                                                           current_hint_state->context,
4309                                                                           PGC_S_SESSION, GUC_ACTION_SAVE,
4310                                                                           true, ERROR);
4311                 }
4312         }
4313
4314         /* do the work */
4315         rel = pg_hint_plan_make_join_rel(root, rel1, rel2);
4316
4317         /* Restore the GUC variables we set above. */
4318         if (join_hint || memoize_hint)
4319         {
4320                 if (join_hint)
4321                         join_hint->base.state = HINT_STATE_USED;
4322
4323                 if (memoize_hint)
4324                         memoize_hint->base.state = HINT_STATE_USED;
4325
4326                 AtEOXact_GUC(true, save_nestlevel);
4327         }
4328
4329         return rel;
4330 }
4331
4332 /*
4333  * TODO : comment
4334  */
4335 static void
4336 add_paths_to_joinrel_wrapper(PlannerInfo *root,
4337                                                          RelOptInfo *joinrel,
4338                                                          RelOptInfo *outerrel,
4339                                                          RelOptInfo *innerrel,
4340                                                          JoinType jointype,
4341                                                          SpecialJoinInfo *sjinfo,
4342                                                          List *restrictlist)
4343 {
4344         Relids                  joinrelids;
4345         JoinMethodHint *join_hint;
4346         JoinMethodHint *memoize_hint;
4347         int                             save_nestlevel;
4348
4349         joinrelids = bms_union(outerrel->relids, innerrel->relids);
4350         join_hint = find_join_hint(joinrelids);
4351         memoize_hint = find_memoize_hint(joinrelids);
4352         bms_free(joinrelids);
4353
4354         /* reject the found hints if they don't match this join */
4355         if (join_hint && join_hint->inner_nrels == 0)
4356                 join_hint = NULL;
4357
4358         if (memoize_hint && memoize_hint->inner_nrels == 0)
4359                 memoize_hint = NULL;
4360
4361         /* set up configuration if needed */
4362         if (join_hint || memoize_hint)
4363         {
4364                 save_nestlevel = NewGUCNestLevel();
4365
4366                 if (join_hint)
4367                 {
4368                         if (bms_equal(join_hint->inner_joinrelids, innerrel->relids))
4369                                 set_join_config_options(join_hint->enforce_mask, false,
4370                                                                                 current_hint_state->context);
4371                         else
4372                                 set_join_config_options(DISABLE_ALL_JOIN, false,
4373                                                                                 current_hint_state->context);
4374                 }
4375
4376                 if (memoize_hint)
4377                 {
4378                         bool memoize =
4379                                 memoize_hint->base.hint_keyword == HINT_KEYWORD_MEMOIZE;
4380                         set_config_option_noerror("enable_memoize",
4381                                                                           memoize ? "true" : "false",
4382                                                                           current_hint_state->context,
4383                                                                           PGC_S_SESSION, GUC_ACTION_SAVE,
4384                                                                           true, ERROR);
4385                 }
4386         }
4387
4388         /* generate paths */
4389         add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
4390                                                  sjinfo, restrictlist);
4391
4392         /* restore GUC variables */
4393         if (join_hint || memoize_hint)
4394         {
4395                 if (join_hint)
4396                         join_hint->base.state = HINT_STATE_USED;
4397
4398                 if (memoize_hint)
4399                         memoize_hint->base.state = HINT_STATE_USED;
4400
4401                 AtEOXact_GUC(true, save_nestlevel);
4402         }
4403 }
4404
4405 static int
4406 get_num_baserels(List *initial_rels)
4407 {
4408         int                     nbaserel = 0;
4409         ListCell   *l;
4410
4411         foreach(l, initial_rels)
4412         {
4413                 RelOptInfo *rel = (RelOptInfo *) lfirst(l);
4414
4415                 if (rel->reloptkind == RELOPT_BASEREL)
4416                         nbaserel++;
4417                 else if (rel->reloptkind ==RELOPT_JOINREL)
4418                         nbaserel+= bms_num_members(rel->relids);
4419                 else
4420                 {
4421                         /* other values not expected here */
4422                         elog(ERROR, "unrecognized reloptkind type: %d", rel->reloptkind);
4423                 }
4424         }
4425
4426         return nbaserel;
4427 }
4428
4429 static RelOptInfo *
4430 pg_hint_plan_join_search(PlannerInfo *root, int levels_needed,
4431                                                  List *initial_rels)
4432 {
4433         JoinMethodHint    **join_method_hints;
4434         int                                     nbaserel;
4435         RelOptInfo                 *rel;
4436         int                                     i;
4437         bool                            leading_hint_enable;
4438
4439         /*
4440          * Use standard planner (or geqo planner) if pg_hint_plan is disabled or no
4441          * valid hint is supplied or current nesting depth is nesting depth of SPI
4442          * calls.
4443          */
4444         if (!current_hint_state || hint_inhibit_level > 0)
4445         {
4446                 if (prev_join_search)
4447                         return (*prev_join_search) (root, levels_needed, initial_rels);
4448                 else if (enable_geqo && levels_needed >= geqo_threshold)
4449                         return geqo(root, levels_needed, initial_rels);
4450                 else
4451                         return standard_join_search(root, levels_needed, initial_rels);
4452         }
4453
4454         /*
4455          * In the case using GEQO, only scan method hints and Set hints have
4456          * effect.  Join method and join order is not controllable by hints.
4457          */
4458         if (enable_geqo && levels_needed >= geqo_threshold)
4459                 return geqo(root, levels_needed, initial_rels);
4460
4461         nbaserel = get_num_baserels(initial_rels);
4462         current_hint_state->join_hint_level =
4463                 palloc0(sizeof(List *) * (nbaserel + 1));
4464         join_method_hints = palloc0(sizeof(JoinMethodHint *) * (nbaserel + 1));
4465         current_hint_state->memoize_hint_level =
4466                 palloc0(sizeof(List *) * (nbaserel + 1));
4467
4468         leading_hint_enable = transform_join_hints(current_hint_state,
4469                                                                                            root, nbaserel,
4470                                                                                            initial_rels, join_method_hints);
4471
4472         rel = pg_hint_plan_standard_join_search(root, levels_needed, initial_rels);
4473
4474         /*
4475          * Adjust number of parallel workers of the result rel to the largest
4476          * number of the component paths.
4477          */
4478         if (current_hint_state->num_hints[HINT_TYPE_PARALLEL] > 0)
4479         {
4480                 ListCell   *lc;
4481                 int             nworkers = 0;
4482
4483                 foreach (lc, initial_rels)
4484                 {
4485                         ListCell *lcp;
4486                         RelOptInfo *rel = (RelOptInfo *) lfirst(lc);
4487
4488                         foreach (lcp, rel->partial_pathlist)
4489                         {
4490                                 Path *path = (Path *) lfirst(lcp);
4491
4492                                 if (nworkers < path-> parallel_workers)
4493                                         nworkers = path-> parallel_workers;
4494                         }
4495                 }
4496
4497                 foreach (lc, rel->partial_pathlist)
4498                 {
4499                         Path *path = (Path *) lfirst(lc);
4500
4501                         if (path->parallel_safe && path->parallel_workers < nworkers)
4502                                 path->parallel_workers = nworkers;
4503                 }
4504         }
4505
4506         for (i = 2; i <= nbaserel; i++)
4507         {
4508                 list_free(current_hint_state->join_hint_level[i]);
4509
4510                 /* free Leading hint only */
4511                 if (join_method_hints[i] != NULL &&
4512                         join_method_hints[i]->enforce_mask == ENABLE_ALL_JOIN)
4513                         JoinMethodHintDelete(join_method_hints[i]);
4514         }
4515         pfree(current_hint_state->join_hint_level);
4516         pfree(join_method_hints);
4517
4518         if (leading_hint_enable)
4519                 set_join_config_options(current_hint_state->init_join_mask, true,
4520                                                                 current_hint_state->context);
4521
4522         return rel;
4523 }
4524
4525 /*
4526  * Force number of wokers if instructed by hint
4527  */
4528 void
4529 pg_hint_plan_set_rel_pathlist(PlannerInfo * root, RelOptInfo *rel,
4530                                                           Index rti, RangeTblEntry *rte)
4531 {
4532         ParallelHint   *phint;
4533         ListCell           *l;
4534         int                             found_hints;
4535
4536         /* call the previous hook */
4537         if (prev_set_rel_pathlist)
4538                 prev_set_rel_pathlist(root, rel, rti, rte);
4539
4540         /* Nothing to do if no hint available */
4541         if (current_hint_state == NULL)
4542                 return;
4543
4544         /* Don't touch dummy rels. */
4545         if (IS_DUMMY_REL(rel))
4546                 return;
4547
4548         /*
4549          * We can accept only plain relations, foreign tables and table saples are
4550          * also unacceptable. See set_rel_pathlist.
4551          */
4552         if ((rel->rtekind != RTE_RELATION &&
4553                  rel->rtekind != RTE_SUBQUERY)||
4554                 rte->relkind == RELKIND_FOREIGN_TABLE ||
4555                 rte->tablesample != NULL)
4556                 return;
4557
4558         /*
4559          * Even though UNION ALL node doesn't have particular name so usually it is
4560          * unhintable, turn on parallel when it contains parallel nodes.
4561          */
4562         if (rel->rtekind == RTE_SUBQUERY)
4563         {
4564                 ListCell *lc;
4565                 bool    inhibit_nonparallel = false;
4566
4567                 if (rel->partial_pathlist == NIL)
4568                         return;
4569
4570                 foreach(lc, rel->partial_pathlist)
4571                 {
4572                         ListCell *lcp;
4573                         AppendPath *apath = (AppendPath *) lfirst(lc);
4574                         int             parallel_workers = 0;
4575
4576                         if (!IsA(apath, AppendPath))
4577                                 continue;
4578
4579                         foreach (lcp, apath->subpaths)
4580                         {
4581                                 Path *spath = (Path *) lfirst(lcp);
4582
4583                                 if (spath->parallel_aware &&
4584                                         parallel_workers < spath->parallel_workers)
4585                                         parallel_workers = spath->parallel_workers;
4586                         }
4587
4588                         apath->path.parallel_workers = parallel_workers;
4589                         inhibit_nonparallel = true;
4590                 }
4591
4592                 if (inhibit_nonparallel)
4593                 {
4594                         ListCell *lc;
4595
4596                         foreach(lc, rel->pathlist)
4597                         {
4598                                 Path *path = (Path *) lfirst(lc);
4599
4600                                 if (path->startup_cost < disable_cost)
4601                                 {
4602                                         path->startup_cost += disable_cost;
4603                                         path->total_cost += disable_cost;
4604                                 }
4605                         }
4606                 }
4607
4608                 return;
4609         }
4610
4611         /* We cannot handle if this requires an outer */
4612         if (rel->lateral_relids)
4613                 return;
4614
4615         /* Return if this relation gets no enfocement */
4616         if ((found_hints = setup_hint_enforcement(root, rel, NULL, &phint)) == 0)
4617                 return;
4618
4619         /* Here, we regenerate paths with the current hint restriction */
4620         if (found_hints & HINT_BM_SCAN_METHOD || found_hints & HINT_BM_PARALLEL)
4621         {
4622                 /*
4623                  * When hint is specified on non-parent relations, discard existing
4624                  * paths and regenerate based on the hint considered. Otherwise we
4625                  * already have hinted childx paths then just adjust the number of
4626                  * planned number of workers.
4627                  */
4628                 if (root->simple_rte_array[rel->relid]->inh)
4629                 {
4630                         /* enforce number of workers if requested */
4631                         if (phint && phint->force_parallel)
4632                         {
4633                                 if (phint->nworkers == 0)
4634                                 {
4635                                         list_free_deep(rel->partial_pathlist);
4636                                         rel->partial_pathlist = NIL;
4637                                 }
4638                                 else
4639                                 {
4640                                         /* prioritize partial paths */
4641                                         foreach (l, rel->partial_pathlist)
4642                                         {
4643                                                 Path *ppath = (Path *) lfirst(l);
4644
4645                                                 if (ppath->parallel_safe)
4646                                                 {
4647                                                         ppath->parallel_workers = phint->nworkers;
4648                                                         ppath->startup_cost = 0;
4649                                                         ppath->total_cost = 0;
4650                                                 }
4651                                         }
4652
4653                                         /* disable non-partial paths */
4654                                         foreach (l, rel->pathlist)
4655                                         {
4656                                                 Path *ppath = (Path *) lfirst(l);
4657
4658                                                 if (ppath->startup_cost < disable_cost)
4659                                                 {
4660                                                         ppath->startup_cost += disable_cost;
4661                                                         ppath->total_cost += disable_cost;
4662                                                 }
4663                                         }
4664                                 }
4665                         }
4666                 }
4667                 else
4668                 {
4669                         /* Just discard all the paths considered so far */
4670                         list_free_deep(rel->pathlist);
4671                         rel->pathlist = NIL;
4672                         list_free_deep(rel->partial_pathlist);
4673                         rel->partial_pathlist = NIL;
4674
4675                         /* Regenerate paths with the current enforcement */
4676                         set_plain_rel_pathlist(root, rel, rte);
4677
4678                         /* Additional work to enforce parallel query execution */
4679                         if (phint && phint->nworkers > 0)
4680                         {
4681                                 /*
4682                                  * For Parallel Append to be planned properly, we shouldn't set
4683                                  * the costs of non-partial paths to disable-value.  Lower the
4684                                  * priority of non-parallel paths by setting partial path costs
4685                                  * to 0 instead.
4686                                  */
4687                                 foreach (l, rel->partial_pathlist)
4688                                 {
4689                                         Path *path = (Path *) lfirst(l);
4690
4691                                         path->startup_cost = 0;
4692                                         path->total_cost = 0;
4693                                 }
4694
4695                                 /* enforce number of workers if requested */
4696                                 if (phint->force_parallel)
4697                                 {
4698                                         foreach (l, rel->partial_pathlist)
4699                                         {
4700                                                 Path *ppath = (Path *) lfirst(l);
4701
4702                                                 if (ppath->parallel_safe)
4703                                                         ppath->parallel_workers = phint->nworkers;
4704                                         }
4705                                 }
4706
4707                                 /* Generate gather paths */
4708                                 if (rel->reloptkind == RELOPT_BASEREL &&
4709                                         bms_membership(root->all_baserels) != BMS_SINGLETON)
4710                                         generate_gather_paths(root, rel, false);
4711                         }
4712                 }
4713         }
4714
4715         reset_hint_enforcement();
4716 }
4717
4718 /*
4719  * stmt_beg callback is called when each query in PL/pgSQL function is about
4720  * to be executed.  At that timing, we save query string in the global variable
4721  * plpgsql_query_string to use it in planner hook.  It's safe to use one global
4722  * variable for the purpose, because its content is only necessary until
4723  * planner hook is called for the query, so recursive PL/pgSQL function calls
4724  * don't harm this mechanism.
4725  */
4726 static void
4727 pg_hint_plan_plpgsql_stmt_beg(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
4728 {
4729         plpgsql_recurse_level++;
4730 }
4731
4732 /*
4733  * stmt_end callback is called then each query in PL/pgSQL function has
4734  * finished.  At that timing, we clear plpgsql_query_string to tell planner
4735  * hook that next call is not for a query written in PL/pgSQL block.
4736  */
4737 static void
4738 pg_hint_plan_plpgsql_stmt_end(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
4739 {
4740         plpgsql_recurse_level--;
4741 }
4742
4743 void plpgsql_query_erase_callback(ResourceReleasePhase phase,
4744                                                                   bool isCommit,
4745                                                                   bool isTopLevel,
4746                                                                   void *arg)
4747 {
4748         if (!isTopLevel || phase != RESOURCE_RELEASE_AFTER_LOCKS)
4749                 return;
4750         /* Cancel plpgsql nest level*/
4751         plpgsql_recurse_level = 0;
4752 }
4753
4754
4755 /* include core static functions */
4756 static void populate_joinrel_with_paths(PlannerInfo *root, RelOptInfo *rel1,
4757                                                                                 RelOptInfo *rel2, RelOptInfo *joinrel,
4758                                                                                 SpecialJoinInfo *sjinfo, List *restrictlist);
4759 static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
4760                                                                         Index rti, RangeTblEntry *rte);
4761
4762 #define standard_join_search pg_hint_plan_standard_join_search
4763 #define join_search_one_level pg_hint_plan_join_search_one_level
4764 #define make_join_rel make_join_rel_wrapper
4765 #include "core.c"
4766
4767 #undef make_join_rel
4768 #define make_join_rel pg_hint_plan_make_join_rel
4769 #define add_paths_to_joinrel add_paths_to_joinrel_wrapper
4770 #include "make_join_rel.c"
4771
4772 #include "pg_stat_statements.c"