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