pg_hint_plan.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pg_hint_plan.c
   4  *                do instructions or hints to the planner using C-style block comments
   5  *                of the SQL.
   6  *
   7  * Copyright (c) 2012-2013, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
   8  *
   9  *-------------------------------------------------------------------------
  10  */
  11 #include "postgres.h"
  12 #include "catalog/pg_collation.h"
  13 #include "catalog/pg_index.h"
  14 #include "commands/prepare.h"
  15 #include "mb/pg_wchar.h"
  16 #include "miscadmin.h"
  17 #include "nodes/nodeFuncs.h"
  18 #include "optimizer/clauses.h"
  19 #include "optimizer/cost.h"
  20 #include "optimizer/geqo.h"
  21 #include "optimizer/joininfo.h"
  22 #include "optimizer/pathnode.h"
  23 #include "optimizer/paths.h"
  24 #include "optimizer/plancat.h"
  25 #include "optimizer/planner.h"
  26 #include "optimizer/prep.h"
  27 #include "optimizer/restrictinfo.h"
  28 #include "parser/scansup.h"
  29 #include "tcop/utility.h"
  30 #include "utils/builtins.h"
  31 #include "utils/lsyscache.h"
  32 #include "utils/memutils.h"
  33 #include "utils/rel.h"
  34 #include "utils/syscache.h"
  35 #if PG_VERSION_NUM >= 90200
  36 #include "catalog/pg_class.h"
  37 #endif
  38
  39 #include "executor/spi.h"
  40 #include "catalog/pg_type.h"
  41
  42 #ifdef PG_MODULE_MAGIC
  43 PG_MODULE_MAGIC;
  44 #endif
  45
  46 #if PG_VERSION_NUM < 90100
  47 #error unsupported PostgreSQL version
  48 #endif
  49
  50 #define BLOCK_COMMENT_START             "/*"
  51 #define BLOCK_COMMENT_END               "*/"
  52 #define HINT_COMMENT_KEYWORD    "+"
  53 #define HINT_START                              BLOCK_COMMENT_START HINT_COMMENT_KEYWORD
  54 #define HINT_END                                BLOCK_COMMENT_END
  55
  56 /* hint keywords */
  57 #define HINT_SEQSCAN                    "SeqScan"
  58 #define HINT_INDEXSCAN                  "IndexScan"
  59 #define HINT_INDEXSCANREGEXP    "IndexScanRegexp"
  60 #define HINT_BITMAPSCAN                 "BitmapScan"
  61 #define HINT_BITMAPSCANREGEXP   "BitmapScanRegexp"
  62 #define HINT_TIDSCAN                    "TidScan"
  63 #define HINT_NOSEQSCAN                  "NoSeqScan"
  64 #define HINT_NOINDEXSCAN                "NoIndexScan"
  65 #define HINT_NOBITMAPSCAN               "NoBitmapScan"
  66 #define HINT_NOTIDSCAN                  "NoTidScan"
  67 #if PG_VERSION_NUM >= 90200
  68 #define HINT_INDEXONLYSCAN              "IndexOnlyScan"
  69 #define HINT_INDEXONLYSCANREGEXP        "IndexOnlyScanRegexp"
  70 #define HINT_NOINDEXONLYSCAN    "NoIndexOnlyScan"
  71 #endif
  72 #define HINT_NESTLOOP                   "NestLoop"
  73 #define HINT_MERGEJOIN                  "MergeJoin"
  74 #define HINT_HASHJOIN                   "HashJoin"
  75 #define HINT_NONESTLOOP                 "NoNestLoop"
  76 #define HINT_NOMERGEJOIN                "NoMergeJoin"
  77 #define HINT_NOHASHJOIN                 "NoHashJoin"
  78 #define HINT_LEADING                    "Leading"
  79 #define HINT_SET                                "Set"
  80
  81 #define HINT_ARRAY_DEFAULT_INITSIZE 8
  82
  83 #define hint_ereport(str, detail) \
  84         ereport(pg_hint_plan_parse_messages, \
  85                         (errmsg("hint syntax error at or near \"%s\"", (str)), \
  86                          errdetail detail))
  87
  88 #define skip_space(str) \
  89         while (isspace(*str)) \
  90                 str++;
  91
  92 enum
  93 {
  94         ENABLE_SEQSCAN = 0x01,
  95         ENABLE_INDEXSCAN = 0x02,
  96         ENABLE_BITMAPSCAN = 0x04,
  97         ENABLE_TIDSCAN = 0x08,
  98 #if PG_VERSION_NUM >= 90200
  99         ENABLE_INDEXONLYSCAN = 0x10
 100 #endif
 101 } SCAN_TYPE_BITS;
 102
 103 enum
 104 {
 105         ENABLE_NESTLOOP = 0x01,
 106         ENABLE_MERGEJOIN = 0x02,
 107         ENABLE_HASHJOIN = 0x04
 108 } JOIN_TYPE_BITS;
 109
 110 #if PG_VERSION_NUM >= 90200
 111 #define ENABLE_ALL_SCAN (ENABLE_SEQSCAN | ENABLE_INDEXSCAN | \
 112                                                  ENABLE_BITMAPSCAN | ENABLE_TIDSCAN | \
 113                                                  ENABLE_INDEXONLYSCAN)
 114 #else
 115 #define ENABLE_ALL_SCAN (ENABLE_SEQSCAN | ENABLE_INDEXSCAN | \
 116                                                  ENABLE_BITMAPSCAN | ENABLE_TIDSCAN)
 117 #endif
 118 #define ENABLE_ALL_JOIN (ENABLE_NESTLOOP | ENABLE_MERGEJOIN | ENABLE_HASHJOIN)
 119 #define DISABLE_ALL_SCAN 0
 120 #define DISABLE_ALL_JOIN 0
 121
 122 /* hint keyword of enum type*/
 123 typedef enum HintKeyword
 124 {
 125         HINT_KEYWORD_SEQSCAN,
 126         HINT_KEYWORD_INDEXSCAN,
 127         HINT_KEYWORD_INDEXSCANREGEXP,
 128         HINT_KEYWORD_BITMAPSCAN,
 129         HINT_KEYWORD_BITMAPSCANREGEXP,
 130         HINT_KEYWORD_TIDSCAN,
 131         HINT_KEYWORD_NOSEQSCAN,
 132         HINT_KEYWORD_NOINDEXSCAN,
 133         HINT_KEYWORD_NOBITMAPSCAN,
 134         HINT_KEYWORD_NOTIDSCAN,
 135 #if PG_VERSION_NUM >= 90200
 136         HINT_KEYWORD_INDEXONLYSCAN,
 137         HINT_KEYWORD_INDEXONLYSCANREGEXP,
 138         HINT_KEYWORD_NOINDEXONLYSCAN,
 139 #endif
 140         HINT_KEYWORD_NESTLOOP,
 141         HINT_KEYWORD_MERGEJOIN,
 142         HINT_KEYWORD_HASHJOIN,
 143         HINT_KEYWORD_NONESTLOOP,
 144         HINT_KEYWORD_NOMERGEJOIN,
 145         HINT_KEYWORD_NOHASHJOIN,
 146         HINT_KEYWORD_LEADING,
 147         HINT_KEYWORD_SET,
 148         HINT_KEYWORD_UNRECOGNIZED
 149 } HintKeyword;
 150
 151 typedef struct Hint Hint;
 152 typedef struct HintState HintState;
 153
 154 typedef Hint *(*HintCreateFunction) (const char *hint_str,
 155                                                                          const char *keyword,
 156                                                                          HintKeyword hint_keyword);
 157 typedef void (*HintDeleteFunction) (Hint *hint);
 158 typedef void (*HintDescFunction) (Hint *hint, StringInfo buf);
 159 typedef int (*HintCmpFunction) (const Hint *a, const Hint *b);
 160 typedef const char *(*HintParseFunction) (Hint *hint, HintState *hstate,
 161                                                                                   Query *parse, const char *str);
 162
 163 /* hint types */
 164 #define NUM_HINT_TYPE   4
 165 typedef enum HintType
 166 {
 167         HINT_TYPE_SCAN_METHOD,
 168         HINT_TYPE_JOIN_METHOD,
 169         HINT_TYPE_LEADING,
 170         HINT_TYPE_SET
 171 } HintType;
 172
 173 static const char *HintTypeName[] = {
 174         "scan method",
 175         "join method",
 176         "leading",
 177         "set"
 178 };
 179
 180 /* hint status */
 181 typedef enum HintStatus
 182 {
 183         HINT_STATE_NOTUSED = 0,         /* specified relation not used in query */
 184         HINT_STATE_USED,                        /* hint is used */
 185         HINT_STATE_DUPLICATION,         /* specified hint duplication */
 186         HINT_STATE_ERROR                        /* execute error (parse error does not include
 187                                                                  * it) */
 188 } HintStatus;
 189
 190 #define hint_state_enabled(hint) ((hint)->base.state == HINT_STATE_NOTUSED || \
 191                                                                   (hint)->base.state == HINT_STATE_USED)
 192
 193 /* common data for all hints. */
 194 struct Hint
 195 {
 196         const char                 *hint_str;           /* must not do pfree */
 197         const char                 *keyword;            /* must not do pfree */
 198         HintKeyword                     hint_keyword;
 199         HintType                        type;
 200         HintStatus                      state;
 201         HintDeleteFunction      delete_func;
 202         HintDescFunction        desc_func;
 203         HintCmpFunction         cmp_func;
 204         HintParseFunction       parse_func;
 205 };
 206
 207 /* scan method hints */
 208 typedef struct ScanMethodHint
 209 {
 210         Hint                    base;
 211         char               *relname;
 212         List               *indexnames;
 213         bool                    regexp;
 214         unsigned char   enforce_mask;
 215 } ScanMethodHint;
 216
 217 typedef struct ParentIndexInfo
 218 {
 219         bool            indisunique;
 220         Oid                     method;
 221         List       *column_names;
 222         char       *expression_str;
 223         Oid                *indcollation;
 224         Oid                *opclass;
 225         int16      *indoption;
 226         char       *indpred_str;
 227 } ParentIndexInfo;
 228
 229 /* join method hints */
 230 typedef struct JoinMethodHint
 231 {
 232         Hint                    base;
 233         int                             nrels;
 234         int                             inner_nrels;
 235         char              **relnames;
 236         unsigned char   enforce_mask;
 237         Relids                  joinrelids;
 238         Relids                  inner_joinrelids;
 239 } JoinMethodHint;
 240
 241 /* join order hints */
 242 typedef struct OuterInnerRels
 243 {
 244         char   *relation;
 245         List   *outer_inner_pair;
 246 } OuterInnerRels;
 247
 248 typedef struct LeadingHint
 249 {
 250         Hint                    base;
 251         List               *relations;  /* relation names specified in Leading hint */
 252         OuterInnerRels *outer_inner;
 253 } LeadingHint;
 254
 255 /* change a run-time parameter hints */
 256 typedef struct SetHint
 257 {
 258         Hint    base;
 259         char   *name;                           /* name of variable */
 260         char   *value;
 261         List   *words;
 262 } SetHint;
 263
 264 /*
 265  * Describes a context of hint processing.
 266  */
 267 struct HintState
 268 {
 269         char               *hint_str;                   /* original hint string */
 270
 271         /* all hint */
 272         int                             nall_hints;                     /* # of valid all hints */
 273         int                             max_all_hints;          /* # of slots for all hints */
 274         Hint              **all_hints;                  /* parsed all hints */
 275
 276         /* # of each hints */
 277         int                             num_hints[NUM_HINT_TYPE];
 278
 279         /* for scan method hints */
 280         ScanMethodHint **scan_hints;            /* parsed scan hints */
 281         int                             init_scan_mask;         /* initial value scan parameter */
 282         Index                   parent_relid;           /* inherit parent table relid */
 283         Oid                             parent_rel_oid;     /* inherit parent table relid */
 284         ScanMethodHint *parent_hint;            /* inherit parent table scan hint */
 285         List               *parent_index_infos; /* infomation of inherit parent table's
 286                                                                                  * index */
 287
 288         /* for join method hints */
 289         JoinMethodHint **join_hints;            /* parsed join hints */
 290         int                             init_join_mask;         /* initial value join parameter */
 291         List              **join_hint_level;
 292
 293         /* for Leading hint */
 294         LeadingHint       **leading_hint;               /* parsed Leading hints */
 295
 296         /* for Set hints */
 297         SetHint           **set_hints;                  /* parsed Set hints */
 298         GucContext              context;                        /* which GUC parameters can we set? */
 299 };
 300
 301 /*
 302  * Describes a hint parser module which is bound with particular hint keyword.
 303  */
 304 typedef struct HintParser
 305 {
 306         char                       *keyword;
 307         HintCreateFunction      create_func;
 308         HintKeyword                     hint_keyword;
 309 } HintParser;
 310
 311 /* Module callbacks */
 312 void            _PG_init(void);
 313 void            _PG_fini(void);
 314
 315 static void push_hint(HintState *hstate);
 316 static void pop_hint(void);
 317
 318 static void pg_hint_plan_ProcessUtility(Node *parsetree,
 319                                                                                 const char *queryString,
 320                                                                                 ParamListInfo params, bool isTopLevel,
 321                                                                                 DestReceiver *dest,
 322                                                                                 char *completionTag);
 323 static PlannedStmt *pg_hint_plan_planner(Query *parse, int cursorOptions,
 324                                                                                  ParamListInfo boundParams);
 325 static void pg_hint_plan_get_relation_info(PlannerInfo *root,
 326                                                                                    Oid relationObjectId,
 327                                                                                    bool inhparent, RelOptInfo *rel);
 328 static RelOptInfo *pg_hint_plan_join_search(PlannerInfo *root,
 329                                                                                         int levels_needed,
 330                                                                                         List *initial_rels);
 331
 332 static Hint *ScanMethodHintCreate(const char *hint_str, const char *keyword,
 333                                                                   HintKeyword hint_keyword);
 334 static void ScanMethodHintDelete(ScanMethodHint *hint);
 335 static void ScanMethodHintDesc(ScanMethodHint *hint, StringInfo buf);
 336 static int ScanMethodHintCmp(const ScanMethodHint *a, const ScanMethodHint *b);
 337 static const char *ScanMethodHintParse(ScanMethodHint *hint, HintState *hstate,
 338                                                                            Query *parse, const char *str);
 339 static Hint *JoinMethodHintCreate(const char *hint_str, const char *keyword,
 340                                                                   HintKeyword hint_keyword);
 341 static void JoinMethodHintDelete(JoinMethodHint *hint);
 342 static void JoinMethodHintDesc(JoinMethodHint *hint, StringInfo buf);
 343 static int JoinMethodHintCmp(const JoinMethodHint *a, const JoinMethodHint *b);
 344 static const char *JoinMethodHintParse(JoinMethodHint *hint, HintState *hstate,
 345                                                                            Query *parse, const char *str);
 346 static Hint *LeadingHintCreate(const char *hint_str, const char *keyword,
 347                                                            HintKeyword hint_keyword);
 348 static void LeadingHintDelete(LeadingHint *hint);
 349 static void LeadingHintDesc(LeadingHint *hint, StringInfo buf);
 350 static int LeadingHintCmp(const LeadingHint *a, const LeadingHint *b);
 351 static const char *LeadingHintParse(LeadingHint *hint, HintState *hstate,
 352                                                                         Query *parse, const char *str);
 353 static Hint *SetHintCreate(const char *hint_str, const char *keyword,
 354                                                    HintKeyword hint_keyword);
 355 static void SetHintDelete(SetHint *hint);
 356 static void SetHintDesc(SetHint *hint, StringInfo buf);
 357 static int SetHintCmp(const SetHint *a, const SetHint *b);
 358 static const char *SetHintParse(SetHint *hint, HintState *hstate, Query *parse,
 359                                                                 const char *str);
 360
 361 static void quote_value(StringInfo buf, const char *value);
 362
 363 static const char *parse_quoted_value(const char *str, char **word,
 364                                                                           bool truncate);
 365
 366 RelOptInfo *pg_hint_plan_standard_join_search(PlannerInfo *root,
 367                                                                                           int levels_needed,
 368                                                                                           List *initial_rels);
 369 void pg_hint_plan_join_search_one_level(PlannerInfo *root, int level);
 370 static void make_rels_by_clause_joins(PlannerInfo *root, RelOptInfo *old_rel,
 371                                                                           ListCell *other_rels);
 372 static void make_rels_by_clauseless_joins(PlannerInfo *root,
 373                                                                                   RelOptInfo *old_rel,
 374                                                                                   ListCell *other_rels);
 375 static bool has_join_restriction(PlannerInfo *root, RelOptInfo *rel);
 376 static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
 377                                                                         Index rti, RangeTblEntry *rte);
 378 #if PG_VERSION_NUM >= 90200
 379 static void generate_mergeappend_paths(PlannerInfo *root, RelOptInfo *rel,
 380                                                    List *live_childrels,
 381                                                    List *all_child_pathkeys);
 382 #endif
 383 static List *accumulate_append_subpath(List *subpaths, Path *path);
 384 #if PG_VERSION_NUM < 90200
 385 static void set_dummy_rel_pathlist(RelOptInfo *rel);
 386 #endif
 387 RelOptInfo *pg_hint_plan_make_join_rel(PlannerInfo *root, RelOptInfo *rel1,
 388                                                                            RelOptInfo *rel2);
 389
 390 /* GUC variables */
 391 static bool     pg_hint_plan_enable_hint = true;
 392 static bool     pg_hint_plan_debug_print = false;
 393 static int      pg_hint_plan_parse_messages = INFO;
 394
 395 static const struct config_enum_entry parse_messages_level_options[] = {
 396         {"debug", DEBUG2, true},
 397         {"debug5", DEBUG5, false},
 398         {"debug4", DEBUG4, false},
 399         {"debug3", DEBUG3, false},
 400         {"debug2", DEBUG2, false},
 401         {"debug1", DEBUG1, false},
 402         {"log", LOG, false},
 403         {"info", INFO, false},
 404         {"notice", NOTICE, false},
 405         {"warning", WARNING, false},
 406         {"error", ERROR, false},
 407         /*
 408          * {"fatal", FATAL, true},
 409          * {"panic", PANIC, true},
 410          */
 411         {NULL, 0, false}
 412 };
 413
 414 /* Saved hook values in case of unload */
 415 static ProcessUtility_hook_type prev_ProcessUtility = NULL;
 416 static planner_hook_type prev_planner = NULL;
 417 static get_relation_info_hook_type prev_get_relation_info = NULL;
 418 static join_search_hook_type prev_join_search = NULL;
 419
 420 /* Hold reference to currently active hint */
 421 static HintState *current_hint = NULL;
 422
 423 /*
 424  * List of hint contexts.  We treat the head of the list as the Top of the
 425  * context stack, so current_hint always points the first element of this list.
 426  */
 427 static List *HintStateStack = NIL;
 428
 429 /*
 430  * Holds statement name during executing EXECUTE command.  NULL for other
 431  * statements.
 432  */
 433 static char        *stmt_name = NULL;
 434
 435 static const HintParser parsers[] = {
 436         {HINT_SEQSCAN, ScanMethodHintCreate, HINT_KEYWORD_SEQSCAN},
 437         {HINT_INDEXSCAN, ScanMethodHintCreate, HINT_KEYWORD_INDEXSCAN},
 438         {HINT_INDEXSCANREGEXP, ScanMethodHintCreate, HINT_KEYWORD_INDEXSCANREGEXP},
 439         {HINT_BITMAPSCAN, ScanMethodHintCreate, HINT_KEYWORD_BITMAPSCAN},
 440         {HINT_BITMAPSCANREGEXP, ScanMethodHintCreate,
 441          HINT_KEYWORD_BITMAPSCANREGEXP},
 442         {HINT_TIDSCAN, ScanMethodHintCreate, HINT_KEYWORD_TIDSCAN},
 443         {HINT_NOSEQSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOSEQSCAN},
 444         {HINT_NOINDEXSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOINDEXSCAN},
 445         {HINT_NOBITMAPSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOBITMAPSCAN},
 446         {HINT_NOTIDSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOTIDSCAN},
 447 #if PG_VERSION_NUM >= 90200
 448         {HINT_INDEXONLYSCAN, ScanMethodHintCreate, HINT_KEYWORD_INDEXONLYSCAN},
 449         {HINT_INDEXONLYSCANREGEXP, ScanMethodHintCreate,
 450          HINT_KEYWORD_INDEXONLYSCANREGEXP},
 451         {HINT_NOINDEXONLYSCAN, ScanMethodHintCreate, HINT_KEYWORD_NOINDEXONLYSCAN},
 452 #endif
 453         {HINT_NESTLOOP, JoinMethodHintCreate, HINT_KEYWORD_NESTLOOP},
 454         {HINT_MERGEJOIN, JoinMethodHintCreate, HINT_KEYWORD_MERGEJOIN},
 455         {HINT_HASHJOIN, JoinMethodHintCreate, HINT_KEYWORD_HASHJOIN},
 456         {HINT_NONESTLOOP, JoinMethodHintCreate, HINT_KEYWORD_NONESTLOOP},
 457         {HINT_NOMERGEJOIN, JoinMethodHintCreate, HINT_KEYWORD_NOMERGEJOIN},
 458         {HINT_NOHASHJOIN, JoinMethodHintCreate, HINT_KEYWORD_NOHASHJOIN},
 459         {HINT_LEADING, LeadingHintCreate, HINT_KEYWORD_LEADING},
 460         {HINT_SET, SetHintCreate, HINT_KEYWORD_SET},
 461         {NULL, NULL, HINT_KEYWORD_UNRECOGNIZED}
 462 };
 463
 464 /*
 465  * Module load callbacks
 466  */
 467 void
 468 _PG_init(void)
 469 {
 470         /* Define custom GUC variables. */
 471         DefineCustomBoolVariable("pg_hint_plan.enable_hint",
 472                          "Force planner to use plans specified in the hint comment preceding to the query.",
 473                                                          NULL,
 474                                                          &pg_hint_plan_enable_hint,
 475                                                          true,
 476                                                          PGC_USERSET,
 477                                                          0,
 478                                                          NULL,
 479                                                          NULL,
 480                                                          NULL);
 481
 482         DefineCustomBoolVariable("pg_hint_plan.debug_print",
 483                                                          "Logs results of hint parsing.",
 484                                                          NULL,
 485                                                          &pg_hint_plan_debug_print,
 486                                                          false,
 487                                                          PGC_USERSET,
 488                                                          0,
 489                                                          NULL,
 490                                                          NULL,
 491                                                          NULL);
 492
 493         DefineCustomEnumVariable("pg_hint_plan.parse_messages",
 494                                                          "Message level of parse errors.",
 495                                                          NULL,
 496                                                          &pg_hint_plan_parse_messages,
 497                                                          INFO,
 498                                                          parse_messages_level_options,
 499                                                          PGC_USERSET,
 500                                                          0,
 501                                                          NULL,
 502                                                          NULL,
 503                                                          NULL);
 504
 505         /* Install hooks. */
 506         prev_ProcessUtility = ProcessUtility_hook;
 507         ProcessUtility_hook = pg_hint_plan_ProcessUtility;
 508         prev_planner = planner_hook;
 509         planner_hook = pg_hint_plan_planner;
 510         prev_get_relation_info = get_relation_info_hook;
 511         get_relation_info_hook = pg_hint_plan_get_relation_info;
 512         prev_join_search = join_search_hook;
 513         join_search_hook = pg_hint_plan_join_search;
 514 }
 515
 516 /*
 517  * Module unload callback
 518  * XXX never called
 519  */
 520 void
 521 _PG_fini(void)
 522 {
 523         /* Uninstall hooks. */
 524         ProcessUtility_hook = prev_ProcessUtility;
 525         planner_hook = prev_planner;
 526         get_relation_info_hook = prev_get_relation_info;
 527         join_search_hook = prev_join_search;
 528 }
 529
 530 /*
 531  * create and delete functions the hint object
 532  */
 533
 534 static Hint *
 535 ScanMethodHintCreate(const char *hint_str, const char *keyword,
 536                                          HintKeyword hint_keyword)
 537 {
 538         ScanMethodHint *hint;
 539
 540         hint = palloc(sizeof(ScanMethodHint));
 541         hint->base.hint_str = hint_str;
 542         hint->base.keyword = keyword;
 543         hint->base.hint_keyword = hint_keyword;
 544         hint->base.type = HINT_TYPE_SCAN_METHOD;
 545         hint->base.state = HINT_STATE_NOTUSED;
 546         hint->base.delete_func = (HintDeleteFunction) ScanMethodHintDelete;
 547         hint->base.desc_func = (HintDescFunction) ScanMethodHintDesc;
 548         hint->base.cmp_func = (HintCmpFunction) ScanMethodHintCmp;
 549         hint->base.parse_func = (HintParseFunction) ScanMethodHintParse;
 550         hint->relname = NULL;
 551         hint->indexnames = NIL;
 552         hint->regexp = false;
 553         hint->enforce_mask = 0;
 554
 555         return (Hint *) hint;
 556 }
 557
 558 static void
 559 ScanMethodHintDelete(ScanMethodHint *hint)
 560 {
 561         if (!hint)
 562                 return;
 563
 564         if (hint->relname)
 565                 pfree(hint->relname);
 566         list_free_deep(hint->indexnames);
 567         pfree(hint);
 568 }
 569
 570 static Hint *
 571 JoinMethodHintCreate(const char *hint_str, const char *keyword,
 572                                          HintKeyword hint_keyword)
 573 {
 574         JoinMethodHint *hint;
 575
 576         hint = palloc(sizeof(JoinMethodHint));
 577         hint->base.hint_str = hint_str;
 578         hint->base.keyword = keyword;
 579         hint->base.hint_keyword = hint_keyword;
 580         hint->base.type = HINT_TYPE_JOIN_METHOD;
 581         hint->base.state = HINT_STATE_NOTUSED;
 582         hint->base.delete_func = (HintDeleteFunction) JoinMethodHintDelete;
 583         hint->base.desc_func = (HintDescFunction) JoinMethodHintDesc;
 584         hint->base.cmp_func = (HintCmpFunction) JoinMethodHintCmp;
 585         hint->base.parse_func = (HintParseFunction) JoinMethodHintParse;
 586         hint->nrels = 0;
 587         hint->inner_nrels = 0;
 588         hint->relnames = NULL;
 589         hint->enforce_mask = 0;
 590         hint->joinrelids = NULL;
 591         hint->inner_joinrelids = NULL;
 592
 593         return (Hint *) hint;
 594 }
 595
 596 static void
 597 JoinMethodHintDelete(JoinMethodHint *hint)
 598 {
 599         if (!hint)
 600                 return;
 601
 602         if (hint->relnames)
 603         {
 604                 int     i;
 605
 606                 for (i = 0; i < hint->nrels; i++)
 607                         pfree(hint->relnames[i]);
 608                 pfree(hint->relnames);
 609         }
 610
 611         bms_free(hint->joinrelids);
 612         bms_free(hint->inner_joinrelids);
 613         pfree(hint);
 614 }
 615
 616 static Hint *
 617 LeadingHintCreate(const char *hint_str, const char *keyword,
 618                                   HintKeyword hint_keyword)
 619 {
 620         LeadingHint        *hint;
 621
 622         hint = palloc(sizeof(LeadingHint));
 623         hint->base.hint_str = hint_str;
 624         hint->base.keyword = keyword;
 625         hint->base.hint_keyword = hint_keyword;
 626         hint->base.type = HINT_TYPE_LEADING;
 627         hint->base.state = HINT_STATE_NOTUSED;
 628         hint->base.delete_func = (HintDeleteFunction)LeadingHintDelete;
 629         hint->base.desc_func = (HintDescFunction) LeadingHintDesc;
 630         hint->base.cmp_func = (HintCmpFunction) LeadingHintCmp;
 631         hint->base.parse_func = (HintParseFunction) LeadingHintParse;
 632         hint->relations = NIL;
 633         hint->outer_inner = NULL;
 634
 635         return (Hint *) hint;
 636 }
 637
 638 static void
 639 LeadingHintDelete(LeadingHint *hint)
 640 {
 641         if (!hint)
 642                 return;
 643
 644         list_free_deep(hint->relations);
 645         if (hint->outer_inner)
 646                 pfree(hint->outer_inner);
 647         pfree(hint);
 648 }
 649
 650 static Hint *
 651 SetHintCreate(const char *hint_str, const char *keyword,
 652                           HintKeyword hint_keyword)
 653 {
 654         SetHint    *hint;
 655
 656         hint = palloc(sizeof(SetHint));
 657         hint->base.hint_str = hint_str;
 658         hint->base.keyword = keyword;
 659         hint->base.hint_keyword = hint_keyword;
 660         hint->base.type = HINT_TYPE_SET;
 661         hint->base.state = HINT_STATE_NOTUSED;
 662         hint->base.delete_func = (HintDeleteFunction) SetHintDelete;
 663         hint->base.desc_func = (HintDescFunction) SetHintDesc;
 664         hint->base.cmp_func = (HintCmpFunction) SetHintCmp;
 665         hint->base.parse_func = (HintParseFunction) SetHintParse;
 666         hint->name = NULL;
 667         hint->value = NULL;
 668         hint->words = NIL;
 669
 670         return (Hint *) hint;
 671 }
 672
 673 static void
 674 SetHintDelete(SetHint *hint)
 675 {
 676         if (!hint)
 677                 return;
 678
 679         if (hint->name)
 680                 pfree(hint->name);
 681         if (hint->value)
 682                 pfree(hint->value);
 683         if (hint->words)
 684                 list_free(hint->words);
 685         pfree(hint);
 686 }
 687
 688 static HintState *
 689 HintStateCreate(void)
 690 {
 691         HintState   *hstate;
 692
 693         hstate = palloc(sizeof(HintState));
 694         hstate->hint_str = NULL;
 695         hstate->nall_hints = 0;
 696         hstate->max_all_hints = 0;
 697         hstate->all_hints = NULL;
 698         memset(hstate->num_hints, 0, sizeof(hstate->num_hints));
 699         hstate->scan_hints = NULL;
 700         hstate->init_scan_mask = 0;
 701         hstate->parent_relid = 0;
 702         hstate->parent_rel_oid = InvalidOid;
 703         hstate->parent_hint = NULL;
 704         hstate->parent_index_infos = NIL;
 705         hstate->join_hints = NULL;
 706         hstate->init_join_mask = 0;
 707         hstate->join_hint_level = NULL;
 708         hstate->leading_hint = NULL;
 709         hstate->context = superuser() ? PGC_SUSET : PGC_USERSET;
 710         hstate->set_hints = NULL;
 711
 712         return hstate;
 713 }
 714
 715 static void
 716 HintStateDelete(HintState *hstate)
 717 {
 718         int                     i;
 719
 720         if (!hstate)
 721                 return;
 722
 723         if (hstate->hint_str)
 724                 pfree(hstate->hint_str);
 725
 726         for (i = 0; i < hstate->num_hints[HINT_TYPE_SCAN_METHOD]; i++)
 727                 hstate->all_hints[i]->delete_func(hstate->all_hints[i]);
 728         if (hstate->all_hints)
 729                 pfree(hstate->all_hints);
 730         if (hstate->parent_index_infos)
 731                 list_free(hstate->parent_index_infos);
 732 }
 733
 734 /*
 735  * Copy given value into buf, with quoting with '"' if necessary.
 736  */
 737 static void
 738 quote_value(StringInfo buf, const char *value)
 739 {
 740         bool            need_quote = false;
 741         const char *str;
 742
 743         for (str = value; *str != '\0'; str++)
 744         {
 745                 if (isspace(*str) || *str == '(' || *str == ')' || *str == '"')
 746                 {
 747                         need_quote = true;
 748                         appendStringInfoCharMacro(buf, '"');
 749                         break;
 750                 }
 751         }
 752
 753         for (str = value; *str != '\0'; str++)
 754         {
 755                 if (*str == '"')
 756                         appendStringInfoCharMacro(buf, '"');
 757
 758                 appendStringInfoCharMacro(buf, *str);
 759         }
 760
 761         if (need_quote)
 762                 appendStringInfoCharMacro(buf, '"');
 763 }
 764
 765 static void
 766 ScanMethodHintDesc(ScanMethodHint *hint, StringInfo buf)
 767 {
 768         ListCell   *l;
 769
 770         appendStringInfo(buf, "%s(", hint->base.keyword);
 771         if (hint->relname != NULL)
 772         {
 773                 quote_value(buf, hint->relname);
 774                 foreach(l, hint->indexnames)
 775                 {
 776                         appendStringInfoCharMacro(buf, ' ');
 777                         quote_value(buf, (char *) lfirst(l));
 778                 }
 779         }
 780         appendStringInfoString(buf, ")\n");
 781 }
 782
 783 static void
 784 JoinMethodHintDesc(JoinMethodHint *hint, StringInfo buf)
 785 {
 786         int     i;
 787
 788         appendStringInfo(buf, "%s(", hint->base.keyword);
 789         if (hint->relnames != NULL)
 790         {
 791                 quote_value(buf, hint->relnames[0]);
 792                 for (i = 1; i < hint->nrels; i++)
 793                 {
 794                         appendStringInfoCharMacro(buf, ' ');
 795                         quote_value(buf, hint->relnames[i]);
 796                 }
 797         }
 798         appendStringInfoString(buf, ")\n");
 799
 800 }
 801
 802 static void
 803 OuterInnerDesc(OuterInnerRels *outer_inner, StringInfo buf)
 804 {
 805         if (outer_inner->relation == NULL)
 806         {
 807                 bool            is_first;
 808                 ListCell   *l;
 809
 810                 is_first = true;
 811
 812                 appendStringInfoCharMacro(buf, '(');
 813                 foreach(l, outer_inner->outer_inner_pair)
 814                 {
 815                         if (is_first)
 816                                 is_first = false;
 817                         else
 818                                 appendStringInfoCharMacro(buf, ' ');
 819
 820                         OuterInnerDesc(lfirst(l), buf);
 821                 }
 822
 823                 appendStringInfoCharMacro(buf, ')');
 824         }
 825         else
 826                 quote_value(buf, outer_inner->relation);
 827 }
 828
 829 static void
 830 LeadingHintDesc(LeadingHint *hint, StringInfo buf)
 831 {
 832         appendStringInfo(buf, "%s(", HINT_LEADING);
 833         if (hint->outer_inner == NULL)
 834         {
 835                 ListCell   *l;
 836                 bool            is_first;
 837
 838                 is_first = true;
 839
 840                 foreach(l, hint->relations)
 841                 {
 842                         if (is_first)
 843                                 is_first = false;
 844                         else
 845                                 appendStringInfoCharMacro(buf, ' ');
 846
 847                         quote_value(buf, (char *) lfirst(l));
 848                 }
 849         }
 850         else
 851                 OuterInnerDesc(hint->outer_inner, buf);
 852
 853         appendStringInfoString(buf, ")\n");
 854 }
 855
 856 static void
 857 SetHintDesc(SetHint *hint, StringInfo buf)
 858 {
 859         bool            is_first = true;
 860         ListCell   *l;
 861
 862         appendStringInfo(buf, "%s(", HINT_SET);
 863         foreach(l, hint->words)
 864         {
 865                 if (is_first)
 866                         is_first = false;
 867                 else
 868                         appendStringInfoCharMacro(buf, ' ');
 869
 870                 quote_value(buf, (char *) lfirst(l));
 871         }
 872         appendStringInfo(buf, ")\n");
 873 }
 874
 875 /*
 876  * Append string which repserents all hints in a given state to buf, with
 877  * preceding title with them.
 878  */
 879 static void
 880 desc_hint_in_state(HintState *hstate, StringInfo buf, const char *title,
 881                                         HintStatus state)
 882 {
 883         int     i;
 884
 885         appendStringInfo(buf, "%s:\n", title);
 886         for (i = 0; i < hstate->nall_hints; i++)
 887         {
 888                 if (hstate->all_hints[i]->state != state)
 889                         continue;
 890
 891                 hstate->all_hints[i]->desc_func(hstate->all_hints[i], buf);
 892         }
 893 }
 894
 895 /*
 896  * Dump contents of given hstate to server log with log level LOG.
 897  */
 898 static void
 899 HintStateDump(HintState *hstate)
 900 {
 901         StringInfoData  buf;
 902
 903         if (!hstate)
 904         {
 905                 elog(LOG, "pg_hint_plan:\nno hint");
 906                 return;
 907         }
 908
 909         initStringInfo(&buf);
 910
 911         appendStringInfoString(&buf, "pg_hint_plan:\n");
 912         desc_hint_in_state(hstate, &buf, "used hint", HINT_STATE_USED);
 913         desc_hint_in_state(hstate, &buf, "not used hint", HINT_STATE_NOTUSED);
 914         desc_hint_in_state(hstate, &buf, "duplication hint", HINT_STATE_DUPLICATION);
 915         desc_hint_in_state(hstate, &buf, "error hint", HINT_STATE_ERROR);
 916
 917         elog(LOG, "%s", buf.data);
 918
 919         pfree(buf.data);
 920 }
 921
 922 /*
 923  * compare functions
 924  */
 925
 926 static int
 927 RelnameCmp(const void *a, const void *b)
 928 {
 929         const char *relnamea = *((const char **) a);
 930         const char *relnameb = *((const char **) b);
 931
 932         return strcmp(relnamea, relnameb);
 933 }
 934
 935 static int
 936 ScanMethodHintCmp(const ScanMethodHint *a, const ScanMethodHint *b)
 937 {
 938         return RelnameCmp(&a->relname, &b->relname);
 939 }
 940
 941 static int
 942 JoinMethodHintCmp(const JoinMethodHint *a, const JoinMethodHint *b)
 943 {
 944         int     i;
 945
 946         if (a->nrels != b->nrels)
 947                 return a->nrels - b->nrels;
 948
 949         for (i = 0; i < a->nrels; i++)
 950         {
 951                 int     result;
 952                 if ((result = RelnameCmp(&a->relnames[i], &b->relnames[i])) != 0)
 953                         return result;
 954         }
 955
 956         return 0;
 957 }
 958
 959 static int
 960 LeadingHintCmp(const LeadingHint *a, const LeadingHint *b)
 961 {
 962         return 0;
 963 }
 964
 965 static int
 966 SetHintCmp(const SetHint *a, const SetHint *b)
 967 {
 968         return strcmp(a->name, b->name);
 969 }
 970
 971 static int
 972 HintCmp(const void *a, const void *b)
 973 {
 974         const Hint *hinta = *((const Hint **) a);
 975         const Hint *hintb = *((const Hint **) b);
 976
 977         if (hinta->type != hintb->type)
 978                 return hinta->type - hintb->type;
 979         if (hinta->state == HINT_STATE_ERROR)
 980                 return -1;
 981         if (hintb->state == HINT_STATE_ERROR)
 982                 return 1;
 983         return hinta->cmp_func(hinta, hintb);
 984 }
 985
 986 /*
 987  * Returns byte offset of hint b from hint a.  If hint a was specified before
 988  * b, positive value is returned.
 989  */
 990 static int
 991 HintCmpWithPos(const void *a, const void *b)
 992 {
 993         const Hint *hinta = *((const Hint **) a);
 994         const Hint *hintb = *((const Hint **) b);
 995         int             result;
 996
 997         result = HintCmp(a, b);
 998         if (result == 0)
 999                 result = hinta->hint_str - hintb->hint_str;
1000
1001         return result;
1002 }
1003
1004 /*
1005  * parse functions
1006  */
1007 static const char *
1008 parse_keyword(const char *str, StringInfo buf)
1009 {
1010         skip_space(str);
1011
1012         while (!isspace(*str) && *str != '(' && *str != '\0')
1013                 appendStringInfoCharMacro(buf, *str++);
1014
1015         return str;
1016 }
1017
1018 static const char *
1019 skip_parenthesis(const char *str, char parenthesis)
1020 {
1021         skip_space(str);
1022
1023         if (*str != parenthesis)
1024         {
1025                 if (parenthesis == '(')
1026                         hint_ereport(str, ("Opening parenthesis is necessary."));
1027                 else if (parenthesis == ')')
1028                         hint_ereport(str, ("Closing parenthesis is necessary."));
1029
1030                 return NULL;
1031         }
1032
1033         str++;
1034
1035         return str;
1036 }
1037
1038 /*
1039  * Parse a token from str, and store malloc'd copy into word.  A token can be
1040  * quoted with '"'.  Return value is pointer to unparsed portion of original
1041  * string, or NULL if an error occurred.
1042  *
1043  * Parsed token is truncated within NAMEDATALEN-1 bytes, when truncate is true.
1044  */
1045 static const char *
1046 parse_quoted_value(const char *str, char **word, bool truncate)
1047 {
1048         StringInfoData  buf;
1049         bool                    in_quote;
1050
1051         /* Skip leading spaces. */
1052         skip_space(str);
1053
1054         initStringInfo(&buf);
1055         if (*str == '"')
1056         {
1057                 str++;
1058                 in_quote = true;
1059         }
1060         else
1061                 in_quote = false;
1062
1063         while (true)
1064         {
1065                 if (in_quote)
1066                 {
1067                         /* Double quotation must be closed. */
1068                         if (*str == '\0')
1069                         {
1070                                 pfree(buf.data);
1071                                 hint_ereport(str, ("Unterminated quoted string."));
1072                                 return NULL;
1073                         }
1074
1075                         /*
1076                          * Skip escaped double quotation.
1077                          *
1078                          * We don't allow slash-asterisk and asterisk-slash (delimiters of
1079                          * block comments) to be an object name, so users must specify
1080                          * alias for such object names.
1081                          *
1082                          * Those special names can be allowed if we care escaped slashes
1083                          * and asterisks, but we don't.
1084                          */
1085                         if (*str == '"')
1086                         {
1087                                 str++;
1088                                 if (*str != '"')
1089                                         break;
1090                         }
1091                 }
1092                 else if (isspace(*str) || *str == '(' || *str == ')' || *str == '"' ||
1093                                  *str == '\0')
1094                         break;
1095
1096                 appendStringInfoCharMacro(&buf, *str++);
1097         }
1098
1099         if (buf.len == 0)
1100         {
1101                 hint_ereport(str, ("Zero-length delimited string."));
1102
1103                 pfree(buf.data);
1104
1105                 return NULL;
1106         }
1107
1108         /* Truncate name if it's too long */
1109         if (truncate)
1110                 truncate_identifier(buf.data, strlen(buf.data), true);
1111
1112         *word = buf.data;
1113
1114         return str;
1115 }
1116
1117 static OuterInnerRels *
1118 OuterInnerRelsCreate(char *name, List *outer_inner_list)
1119 {
1120         OuterInnerRels *outer_inner;
1121
1122         outer_inner = palloc(sizeof(OuterInnerRels));
1123         outer_inner->relation = name;
1124         outer_inner->outer_inner_pair = outer_inner_list;
1125
1126         return outer_inner;
1127 }
1128
1129 static const char *
1130 parse_parentheses_Leading_in(const char *str, OuterInnerRels **outer_inner)
1131 {
1132         List   *outer_inner_pair = NIL;
1133
1134         if ((str = skip_parenthesis(str, '(')) == NULL)
1135                 return NULL;
1136
1137         skip_space(str);
1138
1139         /* Store words in parentheses into outer_inner_list. */
1140         while(*str != ')' && *str != '\0')
1141         {
1142                 OuterInnerRels *outer_inner_rels;
1143
1144                 if (*str == '(')
1145                 {
1146                         str = parse_parentheses_Leading_in(str, &outer_inner_rels);
1147                         if (str == NULL)
1148                                 break;
1149                 }
1150                 else
1151                 {
1152                         char   *name;
1153
1154                         if ((str = parse_quoted_value(str, &name, true)) == NULL)
1155                                 break;
1156                         else
1157                                 outer_inner_rels = OuterInnerRelsCreate(name, NIL);
1158                 }
1159
1160                 outer_inner_pair = lappend(outer_inner_pair, outer_inner_rels);
1161                 skip_space(str);
1162         }
1163
1164         if (str == NULL ||
1165                 (str = skip_parenthesis(str, ')')) == NULL)
1166         {
1167                 list_free(outer_inner_pair);
1168                 return NULL;
1169         }
1170
1171         *outer_inner = OuterInnerRelsCreate(NULL, outer_inner_pair);
1172
1173         return str;
1174 }
1175
1176 static const char *
1177 parse_parentheses_Leading(const char *str, List **name_list,
1178         OuterInnerRels **outer_inner)
1179 {
1180         char   *name;
1181         bool    truncate = true;
1182
1183         if ((str = skip_parenthesis(str, '(')) == NULL)
1184                 return NULL;
1185
1186         skip_space(str);
1187         if (*str =='(')
1188         {
1189                 if ((str = parse_parentheses_Leading_in(str, outer_inner)) == NULL)
1190                         return NULL;
1191         }
1192         else
1193         {
1194                 /* Store words in parentheses into name_list. */
1195                 while(*str != ')' && *str != '\0')
1196                 {
1197                         if ((str = parse_quoted_value(str, &name, truncate)) == NULL)
1198                         {
1199                                 list_free(*name_list);
1200                                 return NULL;
1201                         }
1202
1203                         *name_list = lappend(*name_list, name);
1204                         skip_space(str);
1205                 }
1206         }
1207
1208         if ((str = skip_parenthesis(str, ')')) == NULL)
1209                 return NULL;
1210         return str;
1211 }
1212
1213 static const char *
1214 parse_parentheses(const char *str, List **name_list, HintKeyword keyword)
1215 {
1216         char   *name;
1217         bool    truncate = true;
1218
1219         if ((str = skip_parenthesis(str, '(')) == NULL)
1220                 return NULL;
1221
1222         skip_space(str);
1223
1224         /* Store words in parentheses into name_list. */
1225         while(*str != ')' && *str != '\0')
1226         {
1227                 if ((str = parse_quoted_value(str, &name, truncate)) == NULL)
1228                 {
1229                         list_free(*name_list);
1230                         return NULL;
1231                 }
1232
1233                 *name_list = lappend(*name_list, name);
1234                 skip_space(str);
1235
1236                 if (keyword == HINT_KEYWORD_INDEXSCANREGEXP ||
1237 #if PG_VERSION_NUM >= 90200
1238                         keyword == HINT_KEYWORD_INDEXONLYSCANREGEXP ||
1239 #endif
1240                         keyword == HINT_KEYWORD_BITMAPSCANREGEXP ||
1241                         keyword == HINT_KEYWORD_SET)
1242                 {
1243                         truncate = false;
1244                 }
1245         }
1246
1247         if ((str = skip_parenthesis(str, ')')) == NULL)
1248                 return NULL;
1249         return str;
1250 }
1251
1252 static void
1253 parse_hints(HintState *hstate, Query *parse, const char *str)
1254 {
1255         StringInfoData  buf;
1256         char               *head;
1257
1258         initStringInfo(&buf);
1259         while (*str != '\0')
1260         {
1261                 const HintParser *parser;
1262
1263                 /* in error message, we output the comment including the keyword. */
1264                 head = (char *) str;
1265
1266                 /* parse only the keyword of the hint. */
1267                 resetStringInfo(&buf);
1268                 str = parse_keyword(str, &buf);
1269
1270                 for (parser = parsers; parser->keyword != NULL; parser++)
1271                 {
1272                         char   *keyword = parser->keyword;
1273                         Hint   *hint;
1274
1275                         if (strcasecmp(buf.data, keyword) != 0)
1276                                 continue;
1277
1278                         hint = parser->create_func(head, keyword, parser->hint_keyword);
1279
1280                         /* parser of each hint does parse in a parenthesis. */
1281                         if ((str = hint->parse_func(hint, hstate, parse, str)) == NULL)
1282                         {
1283                                 hint->delete_func(hint);
1284                                 pfree(buf.data);
1285                                 return;
1286                         }
1287
1288                         /*
1289                          * Add hint information into all_hints array.  If we don't have
1290                          * enough space, double the array.
1291                          */
1292                         if (hstate->nall_hints == 0)
1293                         {
1294                                 hstate->max_all_hints = HINT_ARRAY_DEFAULT_INITSIZE;
1295                                 hstate->all_hints = (Hint **)
1296                                         palloc(sizeof(Hint *) * hstate->max_all_hints);
1297                         }
1298                         else if (hstate->nall_hints == hstate->max_all_hints)
1299                         {
1300                                 hstate->max_all_hints *= 2;
1301                                 hstate->all_hints = (Hint **)
1302                                         repalloc(hstate->all_hints,
1303                                                          sizeof(Hint *) * hstate->max_all_hints);
1304                         }
1305
1306                         hstate->all_hints[hstate->nall_hints] = hint;
1307                         hstate->nall_hints++;
1308
1309                         skip_space(str);
1310
1311                         break;
1312                 }
1313
1314                 if (parser->keyword == NULL)
1315                 {
1316                         hint_ereport(head,
1317                                                  ("Unrecognized hint keyword \"%s\".", buf.data));
1318                         pfree(buf.data);
1319                         return;
1320                 }
1321         }
1322
1323         pfree(buf.data);
1324 }
1325
1326
1327 /* search hint. */
1328 static const char *
1329 get_hints_from_table(const char *client_query, const char *client_application)
1330 {
1331         const char *search_query =
1332                 "SELECT hints "
1333                 "  FROM hint_plan.hints "
1334                 " WHERE norm_query_string = $1 "
1335                 "   AND ( application_name = $2 "
1336                 "    OR application_name = '' ) "
1337                 " ORDER BY application_name DESC";
1338         static SPIPlanPtr plan = NULL;
1339         int             ret;
1340         char   *hints = NULL;
1341         Oid             argtypes[2] = { TEXTOID, TEXTOID };
1342         Datum   values[2];
1343         bool    nulls[2] = { false, false };
1344         text   *qry;
1345         text   *app;
1346
1347         ret = SPI_connect();
1348         if (ret != SPI_OK_CONNECT)
1349                 elog(ERROR, "pg_hint_plan: SPI_connect => %d", ret);
1350
1351         if (plan == NULL)
1352         {
1353                 SPIPlanPtr      p;
1354                 p = SPI_prepare(search_query, 2, argtypes);
1355                 if (p == NULL)
1356                         elog(ERROR, "pg_hint_plan: SPI_prepare => %d", SPI_result);
1357                 plan = SPI_saveplan(p);
1358                 SPI_freeplan(p);
1359         }
1360
1361         qry = cstring_to_text(client_query);
1362         app = cstring_to_text(client_application);
1363         values[0] = PointerGetDatum(qry);
1364         values[1] = PointerGetDatum(app);
1365
1366         pg_hint_plan_enable_hint = false;
1367         ret = SPI_execute_plan(plan, values, nulls, true, 1);
1368         pg_hint_plan_enable_hint = true;
1369         if (ret != SPI_OK_SELECT)
1370                 elog(ERROR, "pg_hint_plan: SPI_execute_plan => %d", ret);
1371
1372         if (SPI_processed > 0)
1373         {
1374                 int              len;
1375                 char    *buf;
1376
1377                 hints = pstrdup(SPI_getvalue(SPI_tuptable->vals[0],
1378                                                                            SPI_tuptable->tupdesc, 1));
1379                 len = strlen(hints);
1380                 buf = SPI_palloc(len + 1);
1381                 memcpy(buf, hints, len);
1382                 buf[len] = '\0';
1383                 hints = buf;
1384         }
1385
1386         SPI_finish();
1387
1388         return hints;
1389 }
1390
1391 /*
1392  * Get client-supplied query string.
1393  */
1394 static const char *
1395 get_query_string(void)
1396 {
1397         const char *p;
1398
1399         if (stmt_name)
1400         {
1401                 PreparedStatement  *entry;
1402
1403                 entry = FetchPreparedStatement(stmt_name, true);
1404                 p = entry->plansource->query_string;
1405         }
1406         else
1407                 p = debug_query_string;
1408
1409         return p;
1410 }
1411
1412 /*
1413  * Get hints from the head block comment in client-supplied query string.
1414  */
1415 static const char *
1416 get_hints_from_comment(const char *p)
1417 {
1418         const char *hint_head;
1419         char       *head;
1420         char       *tail;
1421         int                     len;
1422
1423         if (p == NULL)
1424                 return NULL;
1425
1426         /* extract query head comment. */
1427         hint_head = strstr(p, HINT_START);
1428         if (hint_head == NULL)
1429                 return NULL;
1430         for (;p < hint_head; p++)
1431         {
1432                 /*
1433                  * Allow these characters precedes hint comment:
1434                  *   - digits
1435                  *   - alphabets which are in ASCII range
1436                  *   - space, tabs and new-lines
1437                  *   - underscores, for identifier
1438                  *   - commas, for SELECT clause, EXPLAIN and PREPARE
1439                  *   - parentheses, for EXPLAIN and PREPARE
1440                  *
1441                  * Note that we don't use isalpha() nor isalnum() in ctype.h here to
1442                  * avoid behavior which depends on locale setting.
1443                  */
1444                 if (!(*p >= '0' && *p <= '9') &&
1445                         !(*p >= 'A' && *p <= 'Z') &&
1446                         !(*p >= 'a' && *p <= 'z') &&
1447                         !isspace(*p) &&
1448                         *p != '_' &&
1449                         *p != ',' &&
1450                         *p != '(' && *p != ')')
1451                         return NULL;
1452         }
1453
1454         len = strlen(HINT_START);
1455         head = (char *) p;
1456         p += len;
1457         skip_space(p);
1458
1459         /* find hint end keyword. */
1460         if ((tail = strstr(p, HINT_END)) == NULL)
1461         {
1462                 hint_ereport(head, ("Unterminated block comment."));
1463                 return NULL;
1464         }
1465
1466         /* We don't support nested block comments. */
1467         if ((head = strstr(p, BLOCK_COMMENT_START)) != NULL && head < tail)
1468         {
1469                 hint_ereport(head, ("Nested block comments are not supported."));
1470                 return NULL;
1471         }
1472
1473         /* Make a copy of hint. */
1474         len = tail - p;
1475         head = palloc(len + 1);
1476         memcpy(head, p, len);
1477         head[len] = '\0';
1478         p = head;
1479
1480         return p;
1481 }
1482
1483 /*
1484  * Parse hints that got, create hint struct from parse tree and parse hints.
1485  */
1486 static HintState *
1487 create_hintstate(Query *parse, const char *hints)
1488 {
1489         const char *p;
1490         int                     i;
1491         HintState   *hstate;
1492
1493         if (hints == NULL)
1494                 return NULL;
1495
1496         p = hints;
1497         hstate = HintStateCreate();
1498         hstate->hint_str = (char *) hints;
1499
1500         /* parse each hint. */
1501         parse_hints(hstate, parse, p);
1502
1503         /* When nothing specified a hint, we free HintState and returns NULL. */
1504         if (hstate->nall_hints == 0)
1505         {
1506                 HintStateDelete(hstate);
1507                 return NULL;
1508         }
1509
1510         /* Sort hints in order of original position. */
1511         qsort(hstate->all_hints, hstate->nall_hints, sizeof(Hint *),
1512                   HintCmpWithPos);
1513
1514         /* Count number of hints per hint-type. */
1515         for (i = 0; i < hstate->nall_hints; i++)
1516         {
1517                 Hint   *cur_hint = hstate->all_hints[i];
1518                 hstate->num_hints[cur_hint->type]++;
1519         }
1520
1521         /*
1522          * If an object (or a set of objects) has multiple hints of same hint-type,
1523          * only the last hint is valid and others are igonred in planning.
1524          * Hints except the last are marked as 'duplicated' to remember the order.
1525          */
1526         for (i = 0; i < hstate->nall_hints - 1; i++)
1527         {
1528                 Hint   *cur_hint = hstate->all_hints[i];
1529                 Hint   *next_hint = hstate->all_hints[i + 1];
1530
1531                 /*
1532                  * Leading hint is marked as 'duplicated' in transform_join_hints.
1533                  */
1534                 if (cur_hint->type == HINT_TYPE_LEADING &&
1535                         next_hint->type == HINT_TYPE_LEADING)
1536                         continue;
1537
1538                 /*
1539                  * Note that we need to pass addresses of hint pointers, because
1540                  * HintCmp is designed to sort array of Hint* by qsort.
1541                  */
1542                 if (HintCmp(&cur_hint, &next_hint) == 0)
1543                 {
1544                         hint_ereport(cur_hint->hint_str,
1545                                                  ("Conflict %s hint.", HintTypeName[cur_hint->type]));
1546                         cur_hint->state = HINT_STATE_DUPLICATION;
1547                 }
1548         }
1549
1550         /*
1551          * Make sure that per-type array pointers point proper position in the
1552          * array which consists of all hints.
1553          */
1554         hstate->scan_hints = (ScanMethodHint **) hstate->all_hints;
1555         hstate->join_hints = (JoinMethodHint **) (hstate->scan_hints +
1556                 hstate->num_hints[HINT_TYPE_SCAN_METHOD]);
1557         hstate->leading_hint = (LeadingHint **) (hstate->join_hints +
1558                 hstate->num_hints[HINT_TYPE_JOIN_METHOD]);
1559         hstate->set_hints = (SetHint **) (hstate->leading_hint +
1560                 hstate->num_hints[HINT_TYPE_LEADING]);
1561
1562         return hstate;
1563 }
1564
1565 /*
1566  * Parse inside of parentheses of scan-method hints.
1567  */
1568 static const char *
1569 ScanMethodHintParse(ScanMethodHint *hint, HintState *hstate, Query *parse,
1570                                         const char *str)
1571 {
1572         const char         *keyword = hint->base.keyword;
1573         HintKeyword             hint_keyword = hint->base.hint_keyword;
1574         List               *name_list = NIL;
1575         int                             length;
1576
1577         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
1578                 return NULL;
1579
1580         /* Parse relation name and index name(s) if given hint accepts. */
1581         length = list_length(name_list);
1582         if (length > 0)
1583         {
1584                 hint->relname = linitial(name_list);
1585                 hint->indexnames = list_delete_first(name_list);
1586
1587                 /* check whether the hint accepts index name(s). */
1588                 if (length != 1 &&
1589                         hint_keyword != HINT_KEYWORD_INDEXSCAN &&
1590                         hint_keyword != HINT_KEYWORD_INDEXSCANREGEXP &&
1591 #if PG_VERSION_NUM >= 90200
1592                         hint_keyword != HINT_KEYWORD_INDEXONLYSCAN &&
1593                         hint_keyword != HINT_KEYWORD_INDEXONLYSCANREGEXP &&
1594 #endif
1595                         hint_keyword != HINT_KEYWORD_BITMAPSCAN &&
1596                         hint_keyword != HINT_KEYWORD_BITMAPSCANREGEXP)
1597                 {
1598                         hint_ereport(str,
1599                                                  ("%s hint accepts only one relation.",
1600                                                   hint->base.keyword));
1601                         hint->base.state = HINT_STATE_ERROR;
1602                         return str;
1603                 }
1604         }
1605         else
1606         {
1607                 hint_ereport(str,
1608                                          ("%s hint requires a relation.",
1609                                           hint->base.keyword));
1610                 hint->base.state = HINT_STATE_ERROR;
1611                 return str;
1612         }
1613
1614         /* Set a bit for specified hint. */
1615         switch (hint_keyword)
1616         {
1617                 case HINT_KEYWORD_SEQSCAN:
1618                         hint->enforce_mask = ENABLE_SEQSCAN;
1619                         break;
1620                 case HINT_KEYWORD_INDEXSCAN:
1621                         hint->enforce_mask = ENABLE_INDEXSCAN;
1622                         break;
1623                 case HINT_KEYWORD_INDEXSCANREGEXP:
1624                         hint->enforce_mask = ENABLE_INDEXSCAN;
1625                         hint->regexp = true;
1626                         break;
1627                 case HINT_KEYWORD_BITMAPSCAN:
1628                         hint->enforce_mask = ENABLE_BITMAPSCAN;
1629                         break;
1630                 case HINT_KEYWORD_BITMAPSCANREGEXP:
1631                         hint->enforce_mask = ENABLE_BITMAPSCAN;
1632                         hint->regexp = true;
1633                         break;
1634                 case HINT_KEYWORD_TIDSCAN:
1635                         hint->enforce_mask = ENABLE_TIDSCAN;
1636                         break;
1637                 case HINT_KEYWORD_NOSEQSCAN:
1638                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_SEQSCAN;
1639                         break;
1640                 case HINT_KEYWORD_NOINDEXSCAN:
1641                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_INDEXSCAN;
1642                         break;
1643                 case HINT_KEYWORD_NOBITMAPSCAN:
1644                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_BITMAPSCAN;
1645                         break;
1646                 case HINT_KEYWORD_NOTIDSCAN:
1647                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_TIDSCAN;
1648                         break;
1649 #if PG_VERSION_NUM >= 90200
1650                 case HINT_KEYWORD_INDEXONLYSCAN:
1651                         hint->enforce_mask = ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN;
1652                         break;
1653                 case HINT_KEYWORD_INDEXONLYSCANREGEXP:
1654                         hint->enforce_mask = ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN;
1655                         hint->regexp = true;
1656                         break;
1657                 case HINT_KEYWORD_NOINDEXONLYSCAN:
1658                         hint->enforce_mask = ENABLE_ALL_SCAN ^ ENABLE_INDEXONLYSCAN;
1659                         break;
1660 #endif
1661                 default:
1662                         hint_ereport(str, ("Unrecognized hint keyword \"%s\".", keyword));
1663                         return NULL;
1664                         break;
1665         }
1666
1667         return str;
1668 }
1669
1670 static const char *
1671 JoinMethodHintParse(JoinMethodHint *hint, HintState *hstate, Query *parse,
1672                                         const char *str)
1673 {
1674         const char         *keyword = hint->base.keyword;
1675         HintKeyword             hint_keyword = hint->base.hint_keyword;
1676         List               *name_list = NIL;
1677
1678         if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
1679                 return NULL;
1680
1681         hint->nrels = list_length(name_list);
1682
1683         if (hint->nrels > 0)
1684         {
1685                 ListCell   *l;
1686                 int                     i = 0;
1687
1688                 /*
1689                  * Transform relation names from list to array to sort them with qsort
1690                  * after.
1691                  */
1692                 hint->relnames = palloc(sizeof(char *) * hint->nrels);
1693                 foreach (l, name_list)
1694                 {
1695                         hint->relnames[i] = lfirst(l);
1696                         i++;
1697                 }
1698         }
1699
1700         list_free(name_list);
1701
1702         /* A join hint requires at least two relations */
1703         if (hint->nrels < 2)
1704         {
1705                 hint_ereport(str,
1706                                          ("%s hint requires at least two relations.",
1707                                           hint->base.keyword));
1708                 hint->base.state = HINT_STATE_ERROR;
1709                 return str;
1710         }
1711
1712         /* Sort hints in alphabetical order of relation names. */
1713         qsort(hint->relnames, hint->nrels, sizeof(char *), RelnameCmp);
1714
1715         switch (hint_keyword)
1716         {
1717                 case HINT_KEYWORD_NESTLOOP:
1718                         hint->enforce_mask = ENABLE_NESTLOOP;
1719                         break;
1720                 case HINT_KEYWORD_MERGEJOIN:
1721                         hint->enforce_mask = ENABLE_MERGEJOIN;
1722                         break;
1723                 case HINT_KEYWORD_HASHJOIN:
1724                         hint->enforce_mask = ENABLE_HASHJOIN;
1725                         break;
1726                 case HINT_KEYWORD_NONESTLOOP:
1727                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_NESTLOOP;
1728                         break;
1729                 case HINT_KEYWORD_NOMERGEJOIN:
1730                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_MERGEJOIN;
1731                         break;
1732                 case HINT_KEYWORD_NOHASHJOIN:
1733                         hint->enforce_mask = ENABLE_ALL_JOIN ^ ENABLE_HASHJOIN;
1734                         break;
1735                 default:
1736                         hint_ereport(str, ("Unrecognized hint keyword \"%s\".", keyword));
1737                         return NULL;
1738                         break;
1739         }
1740
1741         return str;
1742 }
1743
1744 static bool
1745 OuterInnerPairCheck(OuterInnerRels *outer_inner)
1746 {
1747         ListCell *l;
1748         if (outer_inner->outer_inner_pair == NIL)
1749         {
1750                 if (outer_inner->relation)
1751                         return true;
1752                 else
1753                         return false;
1754         }
1755
1756         if (list_length(outer_inner->outer_inner_pair) == 2)
1757         {
1758                 foreach(l, outer_inner->outer_inner_pair)
1759                 {
1760                         if (!OuterInnerPairCheck(lfirst(l)))
1761                                 return false;
1762                 }
1763         }
1764         else
1765                 return false;
1766
1767         return true;
1768 }
1769
1770 static List *
1771 OuterInnerList(OuterInnerRels *outer_inner)
1772 {
1773         List               *outer_inner_list = NIL;
1774         ListCell           *l;
1775         OuterInnerRels *outer_inner_rels;
1776
1777         foreach(l, outer_inner->outer_inner_pair)
1778         {
1779                 outer_inner_rels = (OuterInnerRels *)(lfirst(l));
1780
1781                 if (outer_inner_rels->relation != NULL)
1782                         outer_inner_list = lappend(outer_inner_list,
1783                                                                            outer_inner_rels->relation);
1784                 else
1785                         outer_inner_list = list_concat(outer_inner_list,
1786                                                                                    OuterInnerList(outer_inner_rels));
1787         }
1788         return outer_inner_list;
1789 }
1790
1791 static const char *
1792 LeadingHintParse(LeadingHint *hint, HintState *hstate, Query *parse,
1793                                  const char *str)
1794 {
1795         List               *name_list = NIL;
1796         OuterInnerRels *outer_inner = NULL;
1797
1798         if ((str = parse_parentheses_Leading(str, &name_list, &outer_inner)) ==
1799                 NULL)
1800                 return NULL;
1801
1802         if (outer_inner != NULL)
1803                 name_list = OuterInnerList(outer_inner);
1804
1805         hint->relations = name_list;
1806         hint->outer_inner = outer_inner;
1807
1808         /* A Leading hint requires at least two relations */
1809         if ( hint->outer_inner == NULL && list_length(hint->relations) < 2)
1810         {
1811                 hint_ereport(hint->base.hint_str,
1812                                          ("%s hint requires at least two relations.",
1813                                           HINT_LEADING));
1814                 hint->base.state = HINT_STATE_ERROR;
1815         }
1816         else if (hint->outer_inner != NULL &&
1817                          !OuterInnerPairCheck(hint->outer_inner))
1818         {
1819                 hint_ereport(hint->base.hint_str,
1820                                          ("%s hint requires two sets of relations when parentheses nests.",
1821                                           HINT_LEADING));
1822                 hint->base.state = HINT_STATE_ERROR;
1823         }
1824
1825         return str;
1826 }
1827
1828 static const char *
1829 SetHintParse(SetHint *hint, HintState *hstate, Query *parse, const char *str)
1830 {
1831         List   *name_list = NIL;
1832
1833         if ((str = parse_parentheses(str, &name_list, hint->base.hint_keyword))
1834                 == NULL)
1835                 return NULL;
1836
1837         hint->words = name_list;
1838
1839         /* We need both name and value to set GUC parameter. */
1840         if (list_length(name_list) == 2)
1841         {
1842                 hint->name = linitial(name_list);
1843                 hint->value = lsecond(name_list);
1844         }
1845         else
1846         {
1847                 hint_ereport(hint->base.hint_str,
1848                                          ("%s hint requires name and value of GUC parameter.",
1849                                           HINT_SET));
1850                 hint->base.state = HINT_STATE_ERROR;
1851         }
1852
1853         return str;
1854 }
1855
1856 /*
1857  * set GUC parameter functions
1858  */
1859
1860 static int
1861 set_config_option_wrapper(const char *name, const char *value,
1862                                                   GucContext context, GucSource source,
1863                                                   GucAction action, bool changeVal, int elevel)
1864 {
1865         int                             result = 0;
1866         MemoryContext   ccxt = CurrentMemoryContext;
1867
1868         PG_TRY();
1869         {
1870 #if PG_VERSION_NUM >= 90200
1871                 result = set_config_option(name, value, context, source,
1872                                                                    action, changeVal, 0);
1873 #else
1874                 result = set_config_option(name, value, context, source,
1875                                                                    action, changeVal);
1876 #endif
1877         }
1878         PG_CATCH();
1879         {
1880                 ErrorData          *errdata;
1881
1882                 /* Save error info */
1883                 MemoryContextSwitchTo(ccxt);
1884                 errdata = CopyErrorData();
1885                 FlushErrorState();
1886
1887                 ereport(elevel, (errcode(errdata->sqlerrcode),
1888                                 errmsg("%s", errdata->message),
1889                                 errdata->detail ? errdetail("%s", errdata->detail) : 0,
1890                                 errdata->hint ? errhint("%s", errdata->hint) : 0));
1891                 FreeErrorData(errdata);
1892         }
1893         PG_END_TRY();
1894
1895         return result;
1896 }
1897
1898 static int
1899 set_config_options(SetHint **options, int noptions, GucContext context)
1900 {
1901         int     i;
1902         int     save_nestlevel;
1903
1904         save_nestlevel = NewGUCNestLevel();
1905
1906         for (i = 0; i < noptions; i++)
1907         {
1908                 SetHint    *hint = options[i];
1909                 int                     result;
1910
1911                 if (!hint_state_enabled(hint))
1912                         continue;
1913
1914                 result = set_config_option_wrapper(hint->name, hint->value, context,
1915                                                                                    PGC_S_SESSION, GUC_ACTION_SAVE, true,
1916                                                                                    pg_hint_plan_parse_messages);
1917                 if (result != 0)
1918                         hint->base.state = HINT_STATE_USED;
1919                 else
1920                         hint->base.state = HINT_STATE_ERROR;
1921         }
1922
1923         return save_nestlevel;
1924 }
1925
1926 #define SET_CONFIG_OPTION(name, type_bits) \
1927         set_config_option_wrapper((name), \
1928                 (mask & (type_bits)) ? "true" : "false", \
1929                 context, PGC_S_SESSION, GUC_ACTION_SAVE, true, ERROR)
1930
1931 static void
1932 set_scan_config_options(unsigned char enforce_mask, GucContext context)
1933 {
1934         unsigned char   mask;
1935
1936         if (enforce_mask == ENABLE_SEQSCAN || enforce_mask == ENABLE_INDEXSCAN ||
1937                 enforce_mask == ENABLE_BITMAPSCAN || enforce_mask == ENABLE_TIDSCAN
1938 #if PG_VERSION_NUM >= 90200
1939                 || enforce_mask == (ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN)
1940 #endif
1941                 )
1942                 mask = enforce_mask;
1943         else
1944                 mask = enforce_mask & current_hint->init_scan_mask;
1945
1946         SET_CONFIG_OPTION("enable_seqscan", ENABLE_SEQSCAN);
1947         SET_CONFIG_OPTION("enable_indexscan", ENABLE_INDEXSCAN);
1948         SET_CONFIG_OPTION("enable_bitmapscan", ENABLE_BITMAPSCAN);
1949         SET_CONFIG_OPTION("enable_tidscan", ENABLE_TIDSCAN);
1950 #if PG_VERSION_NUM >= 90200
1951         SET_CONFIG_OPTION("enable_indexonlyscan", ENABLE_INDEXONLYSCAN);
1952 #endif
1953 }
1954
1955 static void
1956 set_join_config_options(unsigned char enforce_mask, GucContext context)
1957 {
1958         unsigned char   mask;
1959
1960         if (enforce_mask == ENABLE_NESTLOOP || enforce_mask == ENABLE_MERGEJOIN ||
1961                 enforce_mask == ENABLE_HASHJOIN)
1962                 mask = enforce_mask;
1963         else
1964                 mask = enforce_mask & current_hint->init_join_mask;
1965
1966         SET_CONFIG_OPTION("enable_nestloop", ENABLE_NESTLOOP);
1967         SET_CONFIG_OPTION("enable_mergejoin", ENABLE_MERGEJOIN);
1968         SET_CONFIG_OPTION("enable_hashjoin", ENABLE_HASHJOIN);
1969 }
1970
1971 /*
1972  * pg_hint_plan hook functions
1973  */
1974
1975 static void
1976 pg_hint_plan_ProcessUtility(Node *parsetree, const char *queryString,
1977                                                         ParamListInfo params, bool isTopLevel,
1978                                                         DestReceiver *dest, char *completionTag)
1979 {
1980         Node                               *node;
1981
1982         if (!pg_hint_plan_enable_hint)
1983         {
1984                 if (prev_ProcessUtility)
1985                         (*prev_ProcessUtility) (parsetree, queryString, params,
1986                                                                         isTopLevel, dest, completionTag);
1987                 else
1988                         standard_ProcessUtility(parsetree, queryString, params,
1989                                                                         isTopLevel, dest, completionTag);
1990
1991                 return;
1992         }
1993
1994         node = parsetree;
1995         if (IsA(node, ExplainStmt))
1996         {
1997                 /*
1998                  * Draw out parse tree of actual query from Query struct of EXPLAIN
1999                  * statement.
2000                  */
2001                 ExplainStmt        *stmt;
2002                 Query              *query;
2003
2004                 stmt = (ExplainStmt *) node;
2005
2006                 Assert(IsA(stmt->query, Query));
2007                 query = (Query *) stmt->query;
2008
2009                 if (query->commandType == CMD_UTILITY && query->utilityStmt != NULL)
2010                         node = query->utilityStmt;
2011         }
2012
2013         /*
2014          * If the query was a EXECUTE or CREATE TABLE AS EXECUTE, get query string
2015          * specified to preceding PREPARE command to use it as source of hints.
2016          */
2017         if (IsA(node, ExecuteStmt))
2018         {
2019                 ExecuteStmt        *stmt;
2020
2021                 stmt = (ExecuteStmt *) node;
2022                 stmt_name = stmt->name;
2023         }
2024 #if PG_VERSION_NUM >= 90200
2025         /*
2026          * CREATE AS EXECUTE behavior has changed since 9.2, so we must handle it
2027          * specially here.
2028          */
2029         if (IsA(node, CreateTableAsStmt))
2030         {
2031                 CreateTableAsStmt          *stmt;
2032                 Query              *query;
2033
2034                 stmt = (CreateTableAsStmt *) node;
2035                 Assert(IsA(stmt->query, Query));
2036                 query = (Query *) stmt->query;
2037
2038                 if (query->commandType == CMD_UTILITY &&
2039                         IsA(query->utilityStmt, ExecuteStmt))
2040                 {
2041                         ExecuteStmt *estmt = (ExecuteStmt *) query->utilityStmt;
2042                         stmt_name = estmt->name;
2043                 }
2044         }
2045 #endif
2046         if (stmt_name)
2047         {
2048                 PG_TRY();
2049                 {
2050                         if (prev_ProcessUtility)
2051                                 (*prev_ProcessUtility) (parsetree, queryString, params,
2052                                                                                 isTopLevel, dest, completionTag);
2053                         else
2054                                 standard_ProcessUtility(parsetree, queryString, params,
2055                                                                                 isTopLevel, dest, completionTag);
2056                 }
2057                 PG_CATCH();
2058                 {
2059                         stmt_name = NULL;
2060                         PG_RE_THROW();
2061                 }
2062                 PG_END_TRY();
2063
2064                 stmt_name = NULL;
2065
2066                 return;
2067         }
2068
2069         if (prev_ProcessUtility)
2070                 (*prev_ProcessUtility) (parsetree, queryString, params,
2071                                                                 isTopLevel, dest, completionTag);
2072         else
2073                 standard_ProcessUtility(parsetree, queryString, params,
2074                                                                 isTopLevel, dest, completionTag);
2075 }
2076
2077 /*
2078  * Push a hint into hint stack which is implemented with List struct.  Head of
2079  * list is top of stack.
2080  */
2081 static void
2082 push_hint(HintState *hstate)
2083 {
2084         /* Prepend new hint to the list means pushing to stack. */
2085         HintStateStack = lcons(hstate, HintStateStack);
2086
2087         /* Pushed hint is the one which should be used hereafter. */
2088         current_hint = hstate;
2089 }
2090
2091 /* Pop a hint from hint stack.  Popped hint is automatically discarded. */
2092 static void
2093 pop_hint(void)
2094 {
2095         /* Hint stack must not be empty. */
2096         if(HintStateStack == NIL)
2097                 elog(ERROR, "hint stack is empty");
2098
2099         /*
2100          * Take a hint at the head from the list, and free it.  Switch current_hint
2101          * to point new head (NULL if the list is empty).
2102          */
2103         HintStateStack = list_delete_first(HintStateStack);
2104         HintStateDelete(current_hint);
2105         if(HintStateStack == NIL)
2106                 current_hint = NULL;
2107         else
2108                 current_hint = (HintState *) lfirst(list_head(HintStateStack));
2109 }
2110
2111 static PlannedStmt *
2112 pg_hint_plan_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
2113 {
2114         const char         *hints;
2115         const char         *query;
2116         int                             save_nestlevel;
2117         PlannedStmt        *result;
2118         HintState          *hstate;
2119
2120         /*
2121          * Use standard planner if pg_hint_plan is disabled.  Other hook functions
2122          * try to change plan with current_hint if any, so set it to NULL.
2123          */
2124         if (!pg_hint_plan_enable_hint)
2125                 goto standard_planner_proc;
2126
2127         /* Create hint struct from client-supplied query string. */
2128         query = get_query_string();
2129
2130         /*
2131          * get_hints_from_table
2132          * TODO: replace "app1" with current application_name setting of the
2133          * session.
2134          * XXX: use something instead of debug_query_string?
2135          */
2136         hints = get_hints_from_table(query, application_name);
2137         elog(DEBUG1,
2138                  "pg_hint_plan: get_hints_from_table [%s][%s]=>[%s]",
2139                  query, application_name,
2140                  hints ? hints : "(none)");
2141         if (hints == NULL)
2142                 hints = get_hints_from_comment(query);
2143         hstate = create_hintstate(parse, hints);
2144
2145         /*
2146          * Use standard planner if the statement has not valid hint.  Other hook
2147          * functions try to change plan with current_hint if any, so set it to
2148          * NULL.
2149          */
2150         if (!hstate)
2151                 goto standard_planner_proc;
2152
2153         /*
2154          * Push new hint struct to the hint stack to disable previous hint context.
2155          */
2156         push_hint(hstate);
2157
2158         /* Set GUC parameters which are specified with Set hint. */
2159         save_nestlevel = set_config_options(current_hint->set_hints,
2160                                                                                 current_hint->num_hints[HINT_TYPE_SET],
2161                                                                                 current_hint->context);
2162
2163         if (enable_seqscan)
2164                 current_hint->init_scan_mask |= ENABLE_SEQSCAN;
2165         if (enable_indexscan)
2166                 current_hint->init_scan_mask |= ENABLE_INDEXSCAN;
2167         if (enable_bitmapscan)
2168                 current_hint->init_scan_mask |= ENABLE_BITMAPSCAN;
2169         if (enable_tidscan)
2170                 current_hint->init_scan_mask |= ENABLE_TIDSCAN;
2171 #if PG_VERSION_NUM >= 90200
2172         if (enable_indexonlyscan)
2173                 current_hint->init_scan_mask |= ENABLE_INDEXONLYSCAN;
2174 #endif
2175         if (enable_nestloop)
2176                 current_hint->init_join_mask |= ENABLE_NESTLOOP;
2177         if (enable_mergejoin)
2178                 current_hint->init_join_mask |= ENABLE_MERGEJOIN;
2179         if (enable_hashjoin)
2180                 current_hint->init_join_mask |= ENABLE_HASHJOIN;
2181
2182         /*
2183          * Use PG_TRY mechanism to recover GUC parameters and current_hint to the
2184          * state when this planner started when error occurred in planner.
2185          */
2186         PG_TRY();
2187         {
2188                 if (prev_planner)
2189                         result = (*prev_planner) (parse, cursorOptions, boundParams);
2190                 else
2191                         result = standard_planner(parse, cursorOptions, boundParams);
2192         }
2193         PG_CATCH();
2194         {
2195                 /*
2196                  * Rollback changes of GUC parameters, and pop current hint context
2197                  * from hint stack to rewind the state.
2198                  */
2199                 AtEOXact_GUC(true, save_nestlevel);
2200                 pop_hint();
2201                 PG_RE_THROW();
2202         }
2203         PG_END_TRY();
2204
2205         /* Print hint in debug mode. */
2206         if (pg_hint_plan_debug_print)
2207                 HintStateDump(current_hint);
2208
2209         /*
2210          * Rollback changes of GUC parameters, and pop current hint context from
2211          * hint stack to rewind the state.
2212          */
2213         AtEOXact_GUC(true, save_nestlevel);
2214         pop_hint();
2215
2216         return result;
2217
2218 standard_planner_proc:
2219         current_hint = NULL;
2220         if (prev_planner)
2221                 return (*prev_planner) (parse, cursorOptions, boundParams);
2222         else
2223                 return standard_planner(parse, cursorOptions, boundParams);
2224 }
2225
2226 /*
2227  * Return scan method hint which matches given aliasname.
2228  */
2229 static ScanMethodHint *
2230 find_scan_hint(PlannerInfo *root, RelOptInfo *rel)
2231 {
2232         RangeTblEntry  *rte;
2233         int                             i;
2234
2235         /*
2236          * We can't apply scan method hint if the relation is:
2237          *   - not a base relation
2238          *   - not an ordinary relation (such as join and subquery)
2239          */
2240         if (rel->reloptkind != RELOPT_BASEREL || rel->rtekind != RTE_RELATION)
2241                 return NULL;
2242
2243         rte = root->simple_rte_array[rel->relid];
2244
2245         /* We can't force scan method of foreign tables */
2246         if (rte->relkind == RELKIND_FOREIGN_TABLE)
2247                 return NULL;
2248
2249         /* Find scan method hint, which matches given names, from the list. */
2250         for (i = 0; i < current_hint->num_hints[HINT_TYPE_SCAN_METHOD]; i++)
2251         {
2252                 ScanMethodHint *hint = current_hint->scan_hints[i];
2253
2254                 /* We ignore disabled hints. */
2255                 if (!hint_state_enabled(hint))
2256                         continue;
2257
2258                 if (RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
2259                         return hint;
2260         }
2261
2262         return NULL;
2263 }
2264
2265 /*
2266  * regexeq
2267  *
2268  * Returns TRUE on match, FALSE on no match.
2269  *
2270  *   s1 --- the data to match against
2271  *   s2 --- the pattern
2272  *
2273  * Because we copy s1 to NameData, make the size of s1 less than NAMEDATALEN.
2274  */
2275 static bool
2276 regexpeq(const char *s1, const char *s2)
2277 {
2278         NameData        name;
2279         text       *regexp;
2280         Datum           result;
2281
2282         strcpy(name.data, s1);
2283         regexp = cstring_to_text(s2);
2284
2285         result = DirectFunctionCall2Coll(nameregexeq,
2286                                                                          DEFAULT_COLLATION_OID,
2287                                                                          NameGetDatum(&name),
2288                                                                          PointerGetDatum(regexp));
2289         return DatumGetBool(result);
2290 }
2291
2292 static void
2293 delete_indexes(ScanMethodHint *hint, RelOptInfo *rel, Oid relationObjectId)
2294 {
2295         ListCell           *cell;
2296         ListCell           *prev;
2297         ListCell           *next;
2298         StringInfoData  buf;
2299
2300         /*
2301          * We delete all the IndexOptInfo list and prevent you from being usable by
2302          * a scan.
2303          */
2304         if (hint->enforce_mask == ENABLE_SEQSCAN ||
2305                 hint->enforce_mask == ENABLE_TIDSCAN)
2306         {
2307                 list_free_deep(rel->indexlist);
2308                 rel->indexlist = NIL;
2309                 hint->base.state = HINT_STATE_USED;
2310
2311                 return;
2312         }
2313
2314         /*
2315          * When a list of indexes is not specified, we just use all indexes.
2316          */
2317         if (hint->indexnames == NIL)
2318                 return;
2319
2320         /*
2321          * Leaving only an specified index, we delete it from a IndexOptInfo list
2322          * other than it.
2323          */
2324         prev = NULL;
2325         if (pg_hint_plan_debug_print)
2326                 initStringInfo(&buf);
2327
2328         for (cell = list_head(rel->indexlist); cell; cell = next)
2329         {
2330                 IndexOptInfo   *info = (IndexOptInfo *) lfirst(cell);
2331                 char               *indexname = get_rel_name(info->indexoid);
2332                 ListCell           *l;
2333                 bool                    use_index = false;
2334
2335                 next = lnext(cell);
2336
2337                 foreach(l, hint->indexnames)
2338                 {
2339                         char   *hintname = (char *) lfirst(l);
2340                         bool    result;
2341
2342                         if (hint->regexp)
2343                                 result = regexpeq(indexname, hintname);
2344                         else
2345                                 result = RelnameCmp(&indexname, &hintname) == 0;
2346
2347                         if (result)
2348                         {
2349                                 use_index = true;
2350                                 if (pg_hint_plan_debug_print)
2351                                 {
2352                                         appendStringInfoCharMacro(&buf, ' ');
2353                                         quote_value(&buf, indexname);
2354                                 }
2355
2356                                 break;
2357                         }
2358                 }
2359
2360                 /*
2361                  * to make the index a candidate when definition of this index is
2362                  * matched with the index's definition of current_hint.
2363                  */
2364                 if (OidIsValid(relationObjectId) && !use_index)
2365                 {
2366                         foreach(l, current_hint->parent_index_infos)
2367                         {
2368                                 int                                     i;
2369                                 HeapTuple                       ht_idx;
2370                                 ParentIndexInfo    *p_info = (ParentIndexInfo *)lfirst(l);
2371
2372                                 /* check to match the parameter of unique */
2373                                 if (p_info->indisunique != info->unique)
2374                                         continue;
2375
2376                                 /* check to match the parameter of index's method */
2377                                 if (p_info->method != info->relam)
2378                                         continue;
2379
2380                                 /* to check to match the indexkey's configuration */
2381                                 if ((list_length(p_info->column_names)) !=
2382                                          info->ncolumns)
2383                                         continue;
2384
2385                                 /* check to match the indexkey's configuration */
2386                                 for (i = 0; i < info->ncolumns; i++)
2387                                 {
2388                                         char       *c_attname = NULL;
2389                                         char       *p_attname = NULL;
2390
2391                                         p_attname =
2392                                                 list_nth(p_info->column_names, i);
2393
2394                                         /* both are expressions */
2395                                         if (info->indexkeys[i] == 0 && !p_attname)
2396                                                 continue;
2397
2398                                         /* one's column is expression, the other is not */
2399                                         if (info->indexkeys[i] == 0 || !p_attname)
2400                                                 break;
2401
2402                                         c_attname = get_attname(relationObjectId,
2403                                                                                                 info->indexkeys[i]);
2404
2405                                         if (strcmp(p_attname, c_attname) != 0)
2406                                                 break;
2407
2408                                         if (p_info->indcollation[i] != info->indexcollations[i])
2409                                                 break;
2410
2411                                         if (p_info->opclass[i] != info->opcintype[i])
2412                                                 break;
2413
2414                                         if (((p_info->indoption[i] & INDOPTION_DESC) != 0) !=
2415                                                 info->reverse_sort[i])
2416                                                 break;
2417
2418                                         if (((p_info->indoption[i] & INDOPTION_NULLS_FIRST) != 0) !=
2419                                                 info->nulls_first[i])
2420                                                 break;
2421
2422                                 }
2423
2424                                 if (i != info->ncolumns)
2425                                         continue;
2426
2427                                 if ((p_info->expression_str && (info->indexprs != NIL)) ||
2428                                         (p_info->indpred_str && (info->indpred != NIL)))
2429                                 {
2430                                         /*
2431                                          * Fetch the pg_index tuple by the Oid of the index
2432                                          */
2433                                         ht_idx = SearchSysCache1(INDEXRELID,
2434                                                                                          ObjectIdGetDatum(info->indexoid));
2435
2436                                         /* check to match the expression's parameter of index */
2437                                         if (p_info->expression_str &&
2438                                                 !heap_attisnull(ht_idx, Anum_pg_index_indexprs))
2439                                         {
2440                                                 Datum       exprsDatum;
2441                                                 bool        isnull;
2442                                                 Datum       result;
2443
2444                                                 /*
2445                                                  * to change the expression's parameter of child's
2446                                                  * index to strings
2447                                                  */
2448                                                 exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
2449                                                                                                          Anum_pg_index_indexprs,
2450                                                                                                          &isnull);
2451
2452                                                 result = DirectFunctionCall2(pg_get_expr,
2453                                                                                                          exprsDatum,
2454                                                                                                          ObjectIdGetDatum(
2455                                                                                                                  relationObjectId));
2456
2457                                                 if (strcmp(p_info->expression_str,
2458                                                                    text_to_cstring(DatumGetTextP(result))) != 0)
2459                                                 {
2460                                                         /* Clean up */
2461                                                         ReleaseSysCache(ht_idx);
2462
2463                                                         continue;
2464                                                 }
2465                                         }
2466
2467                                         /* Check to match the predicate's paraameter of index */
2468                                         if (p_info->indpred_str &&
2469                                                 !heap_attisnull(ht_idx, Anum_pg_index_indpred))
2470                                         {
2471                                                 Datum       predDatum;
2472                                                 bool        isnull;
2473                                                 Datum       result;
2474
2475                                                 /*
2476                                                  * to change the predicate's parabeter of child's
2477                                                  * index to strings
2478                                                  */
2479                                                 predDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
2480                                                                                                          Anum_pg_index_indpred,
2481                                                                                                          &isnull);
2482
2483                                                 result = DirectFunctionCall2(pg_get_expr,
2484                                                                                                          predDatum,
2485                                                                                                          ObjectIdGetDatum(
2486                                                                                                                  relationObjectId));
2487
2488                                                 if (strcmp(p_info->indpred_str,
2489                                                                    text_to_cstring(DatumGetTextP(result))) != 0)
2490                                                 {
2491                                                         /* Clean up */
2492                                                         ReleaseSysCache(ht_idx);
2493
2494                                                         continue;
2495                                                 }
2496                                         }
2497
2498                                         /* Clean up */
2499                                         ReleaseSysCache(ht_idx);
2500                                 }
2501                                 else if (p_info->expression_str || (info->indexprs != NIL))
2502                                         continue;
2503                                 else if (p_info->indpred_str || (info->indpred != NIL))
2504                                         continue;
2505
2506                                 use_index = true;
2507
2508                                 /* to log the candidate of index */
2509                                 if (pg_hint_plan_debug_print)
2510                                 {
2511                                         appendStringInfoCharMacro(&buf, ' ');
2512                                         quote_value(&buf, indexname);
2513                                 }
2514
2515                                 break;
2516                         }
2517                 }
2518
2519                 if (!use_index)
2520                         rel->indexlist = list_delete_cell(rel->indexlist, cell, prev);
2521                 else
2522                         prev = cell;
2523
2524                 pfree(indexname);
2525         }
2526
2527         if (pg_hint_plan_debug_print)
2528         {
2529                 char   *relname;
2530                 StringInfoData  rel_buf;
2531
2532                 if (OidIsValid(relationObjectId))
2533                         relname = get_rel_name(relationObjectId);
2534                 else
2535                         relname = hint->relname;
2536
2537                 initStringInfo(&rel_buf);
2538                 quote_value(&rel_buf, relname);
2539
2540                 ereport(LOG,
2541                                 (errmsg("available indexes for %s(%s):%s",
2542                                          hint->base.keyword,
2543                                          rel_buf.data,
2544                                          buf.data)));
2545                 pfree(buf.data);
2546                 pfree(rel_buf.data);
2547         }
2548 }
2549
2550 /*
2551  * Return information of index definition.
2552  */
2553 static ParentIndexInfo *
2554 get_parent_index_info(Oid indexoid, Oid relid)
2555 {
2556         ParentIndexInfo *p_info = palloc(sizeof(ParentIndexInfo));
2557         Relation            indexRelation;
2558         Form_pg_index   index;
2559         char               *attname;
2560         int                             i;
2561
2562         indexRelation = index_open(indexoid, RowExclusiveLock);
2563
2564         index = indexRelation->rd_index;
2565
2566         p_info->indisunique = index->indisunique;
2567         p_info->method = indexRelation->rd_rel->relam;
2568
2569         p_info->column_names = NIL;
2570         p_info->indcollation = (Oid *) palloc(sizeof(Oid) * index->indnatts);
2571         p_info->opclass = (Oid *) palloc(sizeof(Oid) * index->indnatts);
2572         p_info->indoption = (int16 *) palloc(sizeof(Oid) * index->indnatts);
2573
2574         for (i = 0; i < index->indnatts; i++)
2575         {
2576                 attname = get_attname(relid, index->indkey.values[i]);
2577                 p_info->column_names = lappend(p_info->column_names, attname);
2578
2579                 p_info->indcollation[i] = indexRelation->rd_indcollation[i];
2580                 p_info->opclass[i] = indexRelation->rd_opcintype[i];
2581                 p_info->indoption[i] = indexRelation->rd_indoption[i];
2582         }
2583
2584         /*
2585          * to check to match the expression's paraameter of index with child indexes
2586          */
2587         p_info->expression_str = NULL;
2588         if(!heap_attisnull(indexRelation->rd_indextuple, Anum_pg_index_indexprs))
2589         {
2590                 Datum       exprsDatum;
2591                 bool            isnull;
2592                 Datum           result;
2593
2594                 exprsDatum = SysCacheGetAttr(INDEXRELID, indexRelation->rd_indextuple,
2595                                                                          Anum_pg_index_indexprs, &isnull);
2596
2597                 result = DirectFunctionCall2(pg_get_expr,
2598                                                                          exprsDatum,
2599                                                                          ObjectIdGetDatum(relid));
2600
2601                 p_info->expression_str = text_to_cstring(DatumGetTextP(result));
2602         }
2603
2604         /*
2605          * to check to match the predicate's paraameter of index with child indexes
2606          */
2607         p_info->indpred_str = NULL;
2608         if(!heap_attisnull(indexRelation->rd_indextuple, Anum_pg_index_indpred))
2609         {
2610                 Datum       predDatum;
2611                 bool            isnull;
2612                 Datum           result;
2613
2614                 predDatum = SysCacheGetAttr(INDEXRELID, indexRelation->rd_indextuple,
2615                                                                          Anum_pg_index_indpred, &isnull);
2616
2617                 result = DirectFunctionCall2(pg_get_expr,
2618                                                                          predDatum,
2619                                                                          ObjectIdGetDatum(relid));
2620
2621                 p_info->indpred_str = text_to_cstring(DatumGetTextP(result));
2622         }
2623
2624         index_close(indexRelation, NoLock);
2625
2626         return p_info;
2627 }
2628
2629 static void
2630 pg_hint_plan_get_relation_info(PlannerInfo *root, Oid relationObjectId,
2631                                                            bool inhparent, RelOptInfo *rel)
2632 {
2633         ScanMethodHint *hint;
2634
2635         if (prev_get_relation_info)
2636                 (*prev_get_relation_info) (root, relationObjectId, inhparent, rel);
2637
2638         /* Do nothing if we don't have valid hint in this context. */
2639         if (!current_hint)
2640                 return;
2641
2642         if (inhparent)
2643         {
2644                 /* store does relids of parent table. */
2645                 current_hint->parent_relid = rel->relid;
2646                 current_hint->parent_rel_oid = relationObjectId;
2647         }
2648         else if (current_hint->parent_relid != 0)
2649         {
2650                 /*
2651                  * We use the same GUC parameter if this table is the child table of a
2652                  * table called pg_hint_plan_get_relation_info just before that.
2653                  */
2654                 ListCell   *l;
2655
2656                 /* append_rel_list contains all append rels; ignore others */
2657                 foreach(l, root->append_rel_list)
2658                 {
2659                         AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
2660
2661                         /* This rel is child table. */
2662                         if (appinfo->parent_relid == current_hint->parent_relid &&
2663                                 appinfo->child_relid == rel->relid)
2664                         {
2665                                 if (current_hint->parent_hint)
2666                                         delete_indexes(current_hint->parent_hint, rel,
2667                                                                    relationObjectId);
2668
2669                                 return;
2670                         }
2671                 }
2672
2673                 /* This rel is not inherit table. */
2674                 current_hint->parent_relid = 0;
2675                 current_hint->parent_rel_oid = InvalidOid;
2676                 current_hint->parent_hint = NULL;
2677         }
2678
2679         /*
2680          * If scan method hint was given, reset GUC parameters which control
2681          * planner behavior about choosing scan methods.
2682          */
2683         if ((hint = find_scan_hint(root, rel)) == NULL)
2684         {
2685                 set_scan_config_options(current_hint->init_scan_mask,
2686                                                                 current_hint->context);
2687                 return;
2688         }
2689         set_scan_config_options(hint->enforce_mask, current_hint->context);
2690         hint->base.state = HINT_STATE_USED;
2691
2692         if (inhparent)
2693         {
2694                 Relation    relation;
2695                 List       *indexoidlist;
2696                 ListCell   *l;
2697
2698                 current_hint->parent_hint = hint;
2699
2700                 relation = heap_open(relationObjectId, NoLock);
2701                 indexoidlist = RelationGetIndexList(relation);
2702
2703                 foreach(l, indexoidlist)
2704                 {
2705                         Oid         indexoid = lfirst_oid(l);
2706                         char       *indexname = get_rel_name(indexoid);
2707                         bool        use_index = false;
2708                         ListCell   *lc;
2709                         ParentIndexInfo *parent_index_info;
2710
2711                         foreach(lc, hint->indexnames)
2712                         {
2713                                 if (RelnameCmp(&indexname, &lfirst(lc)) == 0)
2714                                 {
2715                                         use_index = true;
2716                                         break;
2717                                 }
2718                         }
2719                         if (!use_index)
2720                                 continue;
2721
2722                         parent_index_info = get_parent_index_info(indexoid,
2723                                                                                                           relationObjectId);
2724                         current_hint->parent_index_infos =
2725                                 lappend(current_hint->parent_index_infos, parent_index_info);
2726                 }
2727                 heap_close(relation, NoLock);
2728         }
2729         else
2730                 delete_indexes(hint, rel, InvalidOid);
2731 }
2732
2733 /*
2734  * Return index of relation which matches given aliasname, or 0 if not found.
2735  * If same aliasname was used multiple times in a query, return -1.
2736  */
2737 static int
2738 find_relid_aliasname(PlannerInfo *root, char *aliasname, List *initial_rels,
2739                                          const char *str)
2740 {
2741         int             i;
2742         Index   found = 0;
2743
2744         for (i = 1; i < root->simple_rel_array_size; i++)
2745         {
2746                 ListCell   *l;
2747
2748                 if (root->simple_rel_array[i] == NULL)
2749                         continue;
2750
2751                 Assert(i == root->simple_rel_array[i]->relid);
2752
2753                 if (RelnameCmp(&aliasname,
2754                                            &root->simple_rte_array[i]->eref->aliasname) != 0)
2755                         continue;
2756
2757                 foreach(l, initial_rels)
2758                 {
2759                         RelOptInfo *rel = (RelOptInfo *) lfirst(l);
2760
2761                         if (rel->reloptkind == RELOPT_BASEREL)
2762                         {
2763                                 if (rel->relid != i)
2764                                         continue;
2765                         }
2766                         else
2767                         {
2768                                 Assert(rel->reloptkind == RELOPT_JOINREL);
2769
2770                                 if (!bms_is_member(i, rel->relids))
2771                                         continue;
2772                         }
2773
2774                         if (found != 0)
2775                         {
2776                                 hint_ereport(str,
2777                                                          ("Relation name \"%s\" is ambiguous.",
2778                                                           aliasname));
2779                                 return -1;
2780                         }
2781
2782                         found = i;
2783                         break;
2784                 }
2785
2786         }
2787
2788         return found;
2789 }
2790
2791 /*
2792  * Return join hint which matches given joinrelids.
2793  */
2794 static JoinMethodHint *
2795 find_join_hint(Relids joinrelids)
2796 {
2797         List       *join_hint;
2798         ListCell   *l;
2799
2800         join_hint = current_hint->join_hint_level[bms_num_members(joinrelids)];
2801
2802         foreach(l, join_hint)
2803         {
2804                 JoinMethodHint *hint = (JoinMethodHint *) lfirst(l);
2805
2806                 if (bms_equal(joinrelids, hint->joinrelids))
2807                         return hint;
2808         }
2809
2810         return NULL;
2811 }
2812
2813 static Relids
2814 OuterInnerJoinCreate(OuterInnerRels *outer_inner, LeadingHint *leading_hint,
2815         PlannerInfo *root, List *initial_rels, HintState *hstate, int nbaserel)
2816 {
2817         OuterInnerRels *outer_rels;
2818         OuterInnerRels *inner_rels;
2819         Relids                  outer_relids;
2820         Relids                  inner_relids;
2821         Relids                  join_relids;
2822         JoinMethodHint *hint;
2823
2824         if (outer_inner->relation != NULL)
2825         {
2826                 return bms_make_singleton(
2827                                         find_relid_aliasname(root, outer_inner->relation,
2828                                                                                  initial_rels,
2829                                                                                  leading_hint->base.hint_str));
2830         }
2831
2832         outer_rels = lfirst(outer_inner->outer_inner_pair->head);
2833         inner_rels = lfirst(outer_inner->outer_inner_pair->tail);
2834
2835         outer_relids = OuterInnerJoinCreate(outer_rels,
2836                                                                                 leading_hint,
2837                                                                                 root,
2838                                                                                 initial_rels,
2839                                                                                 hstate,
2840                                                                                 nbaserel);
2841         inner_relids = OuterInnerJoinCreate(inner_rels,
2842                                                                                 leading_hint,
2843                                                                                 root,
2844                                                                                 initial_rels,
2845                                                                                 hstate,
2846                                                                                 nbaserel);
2847
2848         join_relids = bms_add_members(outer_relids, inner_relids);
2849
2850         if (bms_num_members(join_relids) > nbaserel)
2851                 return join_relids;
2852
2853         /*
2854          * If we don't have join method hint, create new one for the
2855          * join combination with all join methods are enabled.
2856          */
2857         hint = find_join_hint(join_relids);
2858         if (hint == NULL)
2859         {
2860                 /*
2861                  * Here relnames is not set, since Relids bitmap is sufficient to
2862                  * control paths of this query afterward.
2863                  */
2864                 hint = (JoinMethodHint *) JoinMethodHintCreate(
2865                                         leading_hint->base.hint_str,
2866                                         HINT_LEADING,
2867                                         HINT_KEYWORD_LEADING);
2868                 hint->base.state = HINT_STATE_USED;
2869                 hint->nrels = bms_num_members(join_relids);
2870                 hint->enforce_mask = ENABLE_ALL_JOIN;
2871                 hint->joinrelids = bms_copy(join_relids);
2872                 hint->inner_nrels = bms_num_members(inner_relids);
2873                 hint->inner_joinrelids = bms_copy(inner_relids);
2874
2875                 hstate->join_hint_level[hint->nrels] =
2876                         lappend(hstate->join_hint_level[hint->nrels], hint);
2877         }
2878         else
2879         {
2880                 hint->inner_nrels = bms_num_members(inner_relids);
2881                 hint->inner_joinrelids = bms_copy(inner_relids);
2882         }
2883
2884         return join_relids;
2885 }
2886
2887 /*
2888  * Transform join method hint into handy form.
2889  *
2890  *   - create bitmap of relids from alias names, to make it easier to check
2891  *     whether a join path matches a join method hint.
2892  *   - add join method hints which are necessary to enforce join order
2893  *     specified by Leading hint
2894  */
2895 static bool
2896 transform_join_hints(HintState *hstate, PlannerInfo *root, int nbaserel,
2897                 List *initial_rels, JoinMethodHint **join_method_hints)
2898 {
2899         int                             i;
2900         int                             relid;
2901         Relids                  joinrelids;
2902         int                             njoinrels;
2903         ListCell           *l;
2904         char               *relname;
2905         LeadingHint        *lhint = NULL;
2906
2907         /*
2908          * Create bitmap of relids from alias names for each join method hint.
2909          * Bitmaps are more handy than strings in join searching.
2910          */
2911         for (i = 0; i < hstate->num_hints[HINT_TYPE_JOIN_METHOD]; i++)
2912         {
2913                 JoinMethodHint *hint = hstate->join_hints[i];
2914                 int     j;
2915
2916                 if (!hint_state_enabled(hint) || hint->nrels > nbaserel)
2917                         continue;
2918
2919                 bms_free(hint->joinrelids);
2920                 hint->joinrelids = NULL;
2921                 relid = 0;
2922                 for (j = 0; j < hint->nrels; j++)
2923                 {
2924                         relname = hint->relnames[j];
2925
2926                         relid = find_relid_aliasname(root, relname, initial_rels,
2927                                                                                  hint->base.hint_str);
2928
2929                         if (relid == -1)
2930                                 hint->base.state = HINT_STATE_ERROR;
2931
2932                         if (relid <= 0)
2933                                 break;
2934
2935                         if (bms_is_member(relid, hint->joinrelids))
2936                         {
2937                                 hint_ereport(hint->base.hint_str,
2938                                                          ("Relation name \"%s\" is duplicated.", relname));
2939                                 hint->base.state = HINT_STATE_ERROR;
2940                                 break;
2941                         }
2942
2943                         hint->joinrelids = bms_add_member(hint->joinrelids, relid);
2944                 }
2945
2946                 if (relid <= 0 || hint->base.state == HINT_STATE_ERROR)
2947                         continue;
2948
2949                 hstate->join_hint_level[hint->nrels] =
2950                         lappend(hstate->join_hint_level[hint->nrels], hint);
2951         }
2952
2953         /* Do nothing if no Leading hint was supplied. */
2954         if (hstate->num_hints[HINT_TYPE_LEADING] == 0)
2955                 return false;
2956
2957         /*
2958          * Decide to use Leading hint。
2959          */
2960         for (i = 0; i < hstate->num_hints[HINT_TYPE_LEADING]; i++)
2961         {
2962                 LeadingHint        *leading_hint = (LeadingHint *)hstate->leading_hint[i];
2963                 Relids                  relids;
2964
2965                 if (leading_hint->base.state == HINT_STATE_ERROR)
2966                         continue;
2967
2968                 relid = 0;
2969                 relids = NULL;
2970
2971                 foreach(l, leading_hint->relations)
2972                 {
2973                         relname = (char *)lfirst(l);;
2974
2975                         relid = find_relid_aliasname(root, relname, initial_rels,
2976                                                                                  leading_hint->base.hint_str);
2977                         if (relid == -1)
2978                                 leading_hint->base.state = HINT_STATE_ERROR;
2979
2980                         if (relid <= 0)
2981                                 break;
2982
2983                         if (bms_is_member(relid, relids))
2984                         {
2985                                 hint_ereport(leading_hint->base.hint_str,
2986                                                          ("Relation name \"%s\" is duplicated.", relname));
2987                                 leading_hint->base.state = HINT_STATE_ERROR;
2988                                 break;
2989                         }
2990
2991                         relids = bms_add_member(relids, relid);
2992                 }
2993
2994                 if (relid <= 0 || leading_hint->base.state == HINT_STATE_ERROR)
2995                         continue;
2996
2997                 if (lhint != NULL)
2998                 {
2999                         hint_ereport(lhint->base.hint_str,
3000                                  ("Conflict %s hint.", HintTypeName[lhint->base.type]));
3001                         lhint->base.state = HINT_STATE_DUPLICATION;
3002                 }
3003                 leading_hint->base.state = HINT_STATE_USED;
3004                 lhint = leading_hint;
3005         }
3006
3007         /* check to exist Leading hint marked with 'used'. */
3008         if (lhint == NULL)
3009                 return false;
3010
3011         /*
3012          * We need join method hints which fit specified join order in every join
3013          * level.  For example, Leading(A B C) virtually requires following join
3014          * method hints, if no join method hint supplied:
3015          *   - level 1: none
3016          *   - level 2: NestLoop(A B), MergeJoin(A B), HashJoin(A B)
3017          *   - level 3: NestLoop(A B C), MergeJoin(A B C), HashJoin(A B C)
3018          *
3019          * If we already have join method hint which fits specified join order in
3020          * that join level, we leave it as-is and don't add new hints.
3021          */
3022         joinrelids = NULL;
3023         njoinrels = 0;
3024         if (lhint->outer_inner == NULL)
3025         {
3026                 foreach(l, lhint->relations)
3027                 {
3028                         JoinMethodHint *hint;
3029
3030                         relname = (char *)lfirst(l);
3031
3032                         /*
3033                          * Find relid of the relation which has given name.  If we have the
3034                          * name given in Leading hint multiple times in the join, nothing to
3035                          * do.
3036                          */
3037                         relid = find_relid_aliasname(root, relname, initial_rels,
3038                                                                                  hstate->hint_str);
3039
3040                         /* Create bitmap of relids for current join level. */
3041                         joinrelids = bms_add_member(joinrelids, relid);
3042                         njoinrels++;
3043
3044                         /* We never have join method hint for single relation. */
3045                         if (njoinrels < 2)
3046                                 continue;
3047
3048                         /*
3049                          * If we don't have join method hint, create new one for the
3050                          * join combination with all join methods are enabled.
3051                          */
3052                         hint = find_join_hint(joinrelids);
3053                         if (hint == NULL)
3054                         {
3055                                 /*
3056                                  * Here relnames is not set, since Relids bitmap is sufficient
3057                                  * to control paths of this query afterward.
3058                                  */
3059                                 hint = (JoinMethodHint *) JoinMethodHintCreate(
3060                                                                                         lhint->base.hint_str,
3061                                                                                         HINT_LEADING,
3062                                                                                         HINT_KEYWORD_LEADING);
3063                                 hint->base.state = HINT_STATE_USED;
3064                                 hint->nrels = njoinrels;
3065                                 hint->enforce_mask = ENABLE_ALL_JOIN;
3066                                 hint->joinrelids = bms_copy(joinrelids);
3067                         }
3068
3069                         join_method_hints[njoinrels] = hint;
3070
3071                         if (njoinrels >= nbaserel)
3072                                 break;
3073                 }
3074                 bms_free(joinrelids);
3075
3076                 if (njoinrels < 2)
3077                         return false;
3078
3079                 /*
3080                  * Delete all join hints which have different combination from Leading
3081                  * hint.
3082                  */
3083                 for (i = 2; i <= njoinrels; i++)
3084                 {
3085                         list_free(hstate->join_hint_level[i]);
3086
3087                         hstate->join_hint_level[i] = lappend(NIL, join_method_hints[i]);
3088                 }
3089         }
3090         else
3091         {
3092                 joinrelids = OuterInnerJoinCreate(lhint->outer_inner,
3093                                                                                   lhint,
3094                                           root,
3095                                           initial_rels,
3096                                                                                   hstate,
3097                                                                                   nbaserel);
3098
3099                 njoinrels = bms_num_members(joinrelids);
3100                 Assert(njoinrels >= 2);
3101
3102                 /*
3103                  * Delete all join hints which have different combination from Leading
3104                  * hint.
3105                  */
3106                 for (i = 2;i <= njoinrels; i++)
3107                 {
3108                         if (hstate->join_hint_level[i] != NIL)
3109                         {
3110                                 ListCell *prev = NULL;
3111                                 ListCell *next = NULL;
3112                                 for(l = list_head(hstate->join_hint_level[i]); l; l = next)
3113                                 {
3114
3115                                         JoinMethodHint *hint = (JoinMethodHint *)lfirst(l);
3116
3117                                         next = lnext(l);
3118
3119                                         if (hint->inner_nrels == 0 &&
3120                                                 !(bms_intersect(hint->joinrelids, joinrelids) == NULL ||
3121                                                   bms_equal(bms_union(hint->joinrelids, joinrelids),
3122                                                   hint->joinrelids)))
3123                                         {
3124                                                 hstate->join_hint_level[i] =
3125                                                         list_delete_cell(hstate->join_hint_level[i], l,
3126                                                                                          prev);
3127                                         }
3128                                         else
3129                                                 prev = l;
3130                                 }
3131                         }
3132                 }
3133
3134                 bms_free(joinrelids);
3135         }
3136
3137         if (hint_state_enabled(lhint))
3138         {
3139                 set_join_config_options(DISABLE_ALL_JOIN, current_hint->context);
3140                 return true;
3141         }
3142         return false;
3143 }
3144
3145 /*
3146  * set_plain_rel_pathlist
3147  *        Build access paths for a plain relation (no subquery, no inheritance)
3148  *
3149  * This function was copied and edited from set_plain_rel_pathlist() in
3150  * src/backend/optimizer/path/allpaths.c
3151  */
3152 static void
3153 set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
3154 {
3155         /* Consider sequential scan */
3156 #if PG_VERSION_NUM >= 90200
3157         add_path(rel, create_seqscan_path(root, rel, NULL));
3158 #else
3159         add_path(rel, create_seqscan_path(root, rel));
3160 #endif
3161
3162         /* Consider index scans */
3163         create_index_paths(root, rel);
3164
3165         /* Consider TID scans */
3166         create_tidscan_paths(root, rel);
3167
3168         /* Now find the cheapest of the paths for this rel */
3169         set_cheapest(rel);
3170 }
3171
3172 static void
3173 rebuild_scan_path(HintState *hstate, PlannerInfo *root, int level,
3174                                   List *initial_rels)
3175 {
3176         ListCell   *l;
3177
3178         foreach(l, initial_rels)
3179         {
3180                 RelOptInfo         *rel = (RelOptInfo *) lfirst(l);
3181                 RangeTblEntry  *rte;
3182                 ScanMethodHint *hint;
3183
3184                 /* Skip relations which we can't choose scan method. */
3185                 if (rel->reloptkind != RELOPT_BASEREL || rel->rtekind != RTE_RELATION)
3186                         continue;
3187
3188                 rte = root->simple_rte_array[rel->relid];
3189
3190                 /* We can't force scan method of foreign tables */
3191                 if (rte->relkind == RELKIND_FOREIGN_TABLE)
3192                         continue;
3193
3194                 /*
3195                  * Create scan paths with GUC parameters which are at the beginning of
3196                  * planner if scan method hint is not specified, otherwise use
3197                  * specified hints and mark the hint as used.
3198                  */
3199                 if ((hint = find_scan_hint(root, rel)) == NULL)
3200                         set_scan_config_options(hstate->init_scan_mask,
3201                                                                         hstate->context);
3202                 else
3203                 {
3204                         set_scan_config_options(hint->enforce_mask, hstate->context);
3205                         hint->base.state = HINT_STATE_USED;
3206                 }
3207
3208                 list_free_deep(rel->pathlist);
3209                 rel->pathlist = NIL;
3210                 if (rte->inh)
3211                 {
3212                         /* It's an "append relation", process accordingly */
3213                         set_append_rel_pathlist(root, rel, rel->relid, rte);
3214                 }
3215                 else
3216                 {
3217                         set_plain_rel_pathlist(root, rel, rte);
3218                 }
3219         }
3220
3221         /*
3222          * Restore the GUC variables we set above.
3223          */
3224         set_scan_config_options(hstate->init_scan_mask, hstate->context);
3225 }
3226
3227 /*
3228  * wrapper of make_join_rel()
3229  *
3230  * call make_join_rel() after changing enable_* parameters according to given
3231  * hints.
3232  */
3233 static RelOptInfo *
3234 make_join_rel_wrapper(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
3235 {
3236         Relids                  joinrelids;
3237         JoinMethodHint *hint;
3238         RelOptInfo         *rel;
3239         int                             save_nestlevel;
3240
3241         joinrelids = bms_union(rel1->relids, rel2->relids);
3242         hint = find_join_hint(joinrelids);
3243         bms_free(joinrelids);
3244
3245         if (!hint)
3246                 return pg_hint_plan_make_join_rel(root, rel1, rel2);
3247
3248         if (hint->inner_nrels == 0)
3249         {
3250                 save_nestlevel = NewGUCNestLevel();
3251
3252                 set_join_config_options(hint->enforce_mask, current_hint->context);
3253
3254                 rel = pg_hint_plan_make_join_rel(root, rel1, rel2);
3255                 hint->base.state = HINT_STATE_USED;
3256
3257                 /*
3258                  * Restore the GUC variables we set above.
3259                  */
3260                 AtEOXact_GUC(true, save_nestlevel);
3261         }
3262         else
3263                 rel = pg_hint_plan_make_join_rel(root, rel1, rel2);
3264
3265         return rel;
3266 }
3267
3268 /*
3269  * TODO : comment
3270  */
3271 static void
3272 add_paths_to_joinrel_wrapper(PlannerInfo *root,
3273                                                          RelOptInfo *joinrel,
3274                                                          RelOptInfo *outerrel,
3275                                                          RelOptInfo *innerrel,
3276                                                          JoinType jointype,
3277                                                          SpecialJoinInfo *sjinfo,
3278                                                          List *restrictlist)
3279 {
3280         ScanMethodHint *scan_hint = NULL;
3281         Relids                  joinrelids;
3282         JoinMethodHint *join_hint;
3283         int                             save_nestlevel;
3284
3285         if ((scan_hint = find_scan_hint(root, innerrel)) != NULL)
3286         {
3287                 set_scan_config_options(scan_hint->enforce_mask, current_hint->context);
3288                 scan_hint->base.state = HINT_STATE_USED;
3289         }
3290
3291         joinrelids = bms_union(outerrel->relids, innerrel->relids);
3292         join_hint = find_join_hint(joinrelids);
3293         bms_free(joinrelids);
3294
3295         if (join_hint && join_hint->inner_nrels != 0)
3296         {
3297                 save_nestlevel = NewGUCNestLevel();
3298
3299                 if (bms_equal(join_hint->inner_joinrelids, innerrel->relids))
3300                 {
3301
3302                         set_join_config_options(join_hint->enforce_mask,
3303                                                                         current_hint->context);
3304
3305                         add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
3306                                                                  sjinfo, restrictlist);
3307                         join_hint->base.state = HINT_STATE_USED;
3308                 }
3309                 else
3310                 {
3311                         set_join_config_options(DISABLE_ALL_JOIN, current_hint->context);
3312                         add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
3313                                                                  sjinfo, restrictlist);
3314                 }
3315
3316                 /*
3317                  * Restore the GUC variables we set above.
3318                  */
3319                 AtEOXact_GUC(true, save_nestlevel);
3320         }
3321         else
3322                 add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
3323                                                          sjinfo, restrictlist);
3324
3325         if (scan_hint != NULL)
3326                 set_scan_config_options(current_hint->init_scan_mask,
3327                                                                 current_hint->context);
3328 }
3329
3330 static int
3331 get_num_baserels(List *initial_rels)
3332 {
3333         int                     nbaserel = 0;
3334         ListCell   *l;
3335
3336         foreach(l, initial_rels)
3337         {
3338                 RelOptInfo *rel = (RelOptInfo *) lfirst(l);
3339
3340                 if (rel->reloptkind == RELOPT_BASEREL)
3341                         nbaserel++;
3342                 else if (rel->reloptkind ==RELOPT_JOINREL)
3343                         nbaserel+= bms_num_members(rel->relids);
3344                 else
3345                 {
3346                         /* other values not expected here */
3347                         elog(ERROR, "unrecognized reloptkind type: %d", rel->reloptkind);
3348                 }
3349         }
3350
3351         return nbaserel;
3352 }
3353
3354 static RelOptInfo *
3355 pg_hint_plan_join_search(PlannerInfo *root, int levels_needed,
3356                                                  List *initial_rels)
3357 {
3358         JoinMethodHint    **join_method_hints;
3359         int                                     nbaserel;
3360         RelOptInfo                 *rel;
3361         int                                     i;
3362         bool                            leading_hint_enable;
3363
3364         /*
3365          * Use standard planner (or geqo planner) if pg_hint_plan is disabled or no
3366          * valid hint is supplied.
3367          */
3368         if (!current_hint)
3369         {
3370                 if (prev_join_search)
3371                         return (*prev_join_search) (root, levels_needed, initial_rels);
3372                 else if (enable_geqo && levels_needed >= geqo_threshold)
3373                         return geqo(root, levels_needed, initial_rels);
3374                 else
3375                         return standard_join_search(root, levels_needed, initial_rels);
3376         }
3377
3378         /* We apply scan method hint rebuild scan path. */
3379         rebuild_scan_path(current_hint, root, levels_needed, initial_rels);
3380
3381         /*
3382          * In the case using GEQO, only scan method hints and Set hints have
3383          * effect.  Join method and join order is not controllable by hints.
3384          */
3385         if (enable_geqo && levels_needed >= geqo_threshold)
3386                 return geqo(root, levels_needed, initial_rels);
3387
3388         nbaserel = get_num_baserels(initial_rels);
3389         current_hint->join_hint_level = palloc0(sizeof(List *) * (nbaserel + 1));
3390         join_method_hints = palloc0(sizeof(JoinMethodHint *) * (nbaserel + 1));
3391
3392         leading_hint_enable = transform_join_hints(current_hint, root, nbaserel,
3393                                                                                            initial_rels, join_method_hints);
3394
3395         rel = pg_hint_plan_standard_join_search(root, levels_needed, initial_rels);
3396
3397         for (i = 2; i <= nbaserel; i++)
3398         {
3399                 list_free(current_hint->join_hint_level[i]);
3400
3401                 /* free Leading hint only */
3402                 if (join_method_hints[i] != NULL &&
3403                         join_method_hints[i]->enforce_mask == ENABLE_ALL_JOIN)
3404                         JoinMethodHintDelete(join_method_hints[i]);
3405         }
3406         pfree(current_hint->join_hint_level);
3407         pfree(join_method_hints);
3408
3409         if (leading_hint_enable)
3410                 set_join_config_options(current_hint->init_join_mask,
3411                                                                 current_hint->context);
3412
3413         return rel;
3414 }
3415
3416 /*
3417  * set_rel_pathlist
3418  *        Build access paths for a base relation
3419  *
3420  * This function was copied and edited from set_rel_pathlist() in
3421  * src/backend/optimizer/path/allpaths.c
3422  */
3423 static void
3424 set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
3425                                  Index rti, RangeTblEntry *rte)
3426 {
3427 #if PG_VERSION_NUM >= 90200
3428         if (IS_DUMMY_REL(rel))
3429         {
3430                 /* We already proved the relation empty, so nothing more to do */
3431         }
3432         else if (rte->inh)
3433 #else
3434         if (rte->inh)
3435 #endif
3436         {
3437                 /* It's an "append relation", process accordingly */
3438                 set_append_rel_pathlist(root, rel, rti, rte);
3439         }
3440         else
3441         {
3442                 if (rel->rtekind == RTE_RELATION)
3443                 {
3444                         if (rte->relkind == RELKIND_RELATION)
3445                         {
3446                                 /* Plain relation */
3447                                 set_plain_rel_pathlist(root, rel, rte);
3448                         }
3449                         else
3450                                 elog(ERROR, "unexpected relkind: %c", rte->relkind);
3451                 }
3452                 else
3453                         elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
3454         }
3455 }
3456
3457 #define standard_join_search pg_hint_plan_standard_join_search
3458 #define join_search_one_level pg_hint_plan_join_search_one_level
3459 #define make_join_rel make_join_rel_wrapper
3460 #include "core.c"
3461
3462 #undef make_join_rel
3463 #define make_join_rel pg_hint_plan_make_join_rel
3464 #define add_paths_to_joinrel add_paths_to_joinrel_wrapper
3465 #include "make_join_rel.c"