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indexam.c
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1 /*-------------------------------------------------------------------------
2  *
3  * indexam.c
4  * general index access method routines
5  *
6  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/access/index/indexam.c
12  *
13  * INTERFACE ROUTINES
14  * index_open - open an index relation by relation OID
15  * index_close - close an index relation
16  * index_beginscan - start a scan of an index with amgettuple
17  * index_beginscan_bitmap - start a scan of an index with amgetbitmap
18  * index_rescan - restart a scan of an index
19  * index_endscan - end a scan
20  * index_insert - insert an index tuple into a relation
21  * index_markpos - mark a scan position
22  * index_restrpos - restore a scan position
23  * index_parallelscan_estimate - estimate shared memory for parallel scan
24  * index_parallelscan_initialize - initialize parallel scan
25  * index_parallelrescan - (re)start a parallel scan of an index
26  * index_beginscan_parallel - join parallel index scan
27  * index_getnext_tid - get the next TID from a scan
28  * index_fetch_heap - get the scan's next heap tuple
29  * index_getnext_slot - get the next tuple from a scan
30  * index_getbitmap - get all tuples from a scan
31  * index_bulk_delete - bulk deletion of index tuples
32  * index_vacuum_cleanup - post-deletion cleanup of an index
33  * index_can_return - does index support index-only scans?
34  * index_getprocid - get a support procedure OID
35  * index_getprocinfo - get a support procedure's lookup info
36  *
37  * NOTES
38  * This file contains the index_ routines which used
39  * to be a scattered collection of stuff in access/genam.
40  *
41  *-------------------------------------------------------------------------
42  */
43 
44 #include "postgres.h"
45 
46 #include "access/amapi.h"
47 #include "access/relation.h"
48 #include "access/reloptions.h"
49 #include "access/relscan.h"
50 #include "access/tableam.h"
51 #include "catalog/index.h"
52 #include "catalog/pg_type.h"
53 #include "nodes/execnodes.h"
54 #include "pgstat.h"
55 #include "storage/lmgr.h"
56 #include "storage/predicate.h"
57 #include "utils/ruleutils.h"
58 #include "utils/snapmgr.h"
59 #include "utils/syscache.h"
60 
61 
62 /* ----------------------------------------------------------------
63  * macros used in index_ routines
64  *
65  * Note: the ReindexIsProcessingIndex() check in RELATION_CHECKS is there
66  * to check that we don't try to scan or do retail insertions into an index
67  * that is currently being rebuilt or pending rebuild. This helps to catch
68  * things that don't work when reindexing system catalogs, as well as prevent
69  * user errors like index expressions that access their own tables. The check
70  * doesn't prevent the actual rebuild because we don't use RELATION_CHECKS
71  * when calling the index AM's ambuild routine, and there is no reason for
72  * ambuild to call its subsidiary routines through this file.
73  * ----------------------------------------------------------------
74  */
75 #define RELATION_CHECKS \
76 do { \
77  Assert(RelationIsValid(indexRelation)); \
78  Assert(PointerIsValid(indexRelation->rd_indam)); \
79  if (unlikely(ReindexIsProcessingIndex(RelationGetRelid(indexRelation)))) \
80  ereport(ERROR, \
81  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), \
82  errmsg("cannot access index \"%s\" while it is being reindexed", \
83  RelationGetRelationName(indexRelation)))); \
84 } while(0)
85 
86 #define SCAN_CHECKS \
87 ( \
88  AssertMacro(IndexScanIsValid(scan)), \
89  AssertMacro(RelationIsValid(scan->indexRelation)), \
90  AssertMacro(PointerIsValid(scan->indexRelation->rd_indam)) \
91 )
92 
93 #define CHECK_REL_PROCEDURE(pname) \
94 do { \
95  if (indexRelation->rd_indam->pname == NULL) \
96  elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
97  CppAsString(pname), RelationGetRelationName(indexRelation)); \
98 } while(0)
99 
100 #define CHECK_SCAN_PROCEDURE(pname) \
101 do { \
102  if (scan->indexRelation->rd_indam->pname == NULL) \
103  elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
104  CppAsString(pname), RelationGetRelationName(scan->indexRelation)); \
105 } while(0)
106 
107 static IndexScanDesc index_beginscan_internal(Relation indexRelation,
108  int nkeys, int norderbys, Snapshot snapshot,
109  ParallelIndexScanDesc pscan, bool temp_snap);
110 static inline void validate_relation_kind(Relation r);
111 
112 
113 /* ----------------------------------------------------------------
114  * index_ interface functions
115  * ----------------------------------------------------------------
116  */
117 
118 /* ----------------
119  * index_open - open an index relation by relation OID
120  *
121  * If lockmode is not "NoLock", the specified kind of lock is
122  * obtained on the index. (Generally, NoLock should only be
123  * used if the caller knows it has some appropriate lock on the
124  * index already.)
125  *
126  * An error is raised if the index does not exist.
127  *
128  * This is a convenience routine adapted for indexscan use.
129  * Some callers may prefer to use relation_open directly.
130  * ----------------
131  */
132 Relation
133 index_open(Oid relationId, LOCKMODE lockmode)
134 {
135  Relation r;
136 
137  r = relation_open(relationId, lockmode);
138 
140 
141  return r;
142 }
143 
144 /* ----------------
145  * try_index_open - open an index relation by relation OID
146  *
147  * Same as index_open, except return NULL instead of failing
148  * if the relation does not exist.
149  * ----------------
150  */
151 Relation
152 try_index_open(Oid relationId, LOCKMODE lockmode)
153 {
154  Relation r;
155 
156  r = try_relation_open(relationId, lockmode);
157 
158  /* leave if index does not exist */
159  if (!r)
160  return NULL;
161 
163 
164  return r;
165 }
166 
167 /* ----------------
168  * index_close - close an index relation
169  *
170  * If lockmode is not "NoLock", we then release the specified lock.
171  *
172  * Note that it is often sensible to hold a lock beyond index_close;
173  * in that case, the lock is released automatically at xact end.
174  * ----------------
175  */
176 void
177 index_close(Relation relation, LOCKMODE lockmode)
178 {
179  LockRelId relid = relation->rd_lockInfo.lockRelId;
180 
181  Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
182 
183  /* The relcache does the real work... */
184  RelationClose(relation);
185 
186  if (lockmode != NoLock)
187  UnlockRelationId(&relid, lockmode);
188 }
189 
190 /* ----------------
191  * validate_relation_kind - check the relation's kind
192  *
193  * Make sure relkind is an index or a partitioned index.
194  * ----------------
195  */
196 static inline void
198 {
199  if (r->rd_rel->relkind != RELKIND_INDEX &&
200  r->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
201  ereport(ERROR,
202  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
203  errmsg("\"%s\" is not an index",
205 }
206 
207 
208 /* ----------------
209  * index_insert - insert an index tuple into a relation
210  * ----------------
211  */
212 bool
213 index_insert(Relation indexRelation,
214  Datum *values,
215  bool *isnull,
216  ItemPointer heap_t_ctid,
217  Relation heapRelation,
218  IndexUniqueCheck checkUnique,
219  bool indexUnchanged,
220  IndexInfo *indexInfo)
221 {
223  CHECK_REL_PROCEDURE(aminsert);
224 
225  if (!(indexRelation->rd_indam->ampredlocks))
226  CheckForSerializableConflictIn(indexRelation,
227  (ItemPointer) NULL,
229 
230  return indexRelation->rd_indam->aminsert(indexRelation, values, isnull,
231  heap_t_ctid, heapRelation,
232  checkUnique, indexUnchanged,
233  indexInfo);
234 }
235 
236 /* -------------------------
237  * index_insert_cleanup - clean up after all index inserts are done
238  * -------------------------
239  */
240 void
242  IndexInfo *indexInfo)
243 {
245  Assert(indexInfo);
246 
247  if (indexRelation->rd_indam->aminsertcleanup && indexInfo->ii_AmCache)
248  indexRelation->rd_indam->aminsertcleanup(indexInfo);
249 }
250 
251 /*
252  * index_beginscan - start a scan of an index with amgettuple
253  *
254  * Caller must be holding suitable locks on the heap and the index.
255  */
258  Relation indexRelation,
259  Snapshot snapshot,
260  int nkeys, int norderbys)
261 {
262  IndexScanDesc scan;
263 
264  Assert(snapshot != InvalidSnapshot);
265 
266  scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
267 
268  /*
269  * Save additional parameters into the scandesc. Everything else was set
270  * up by RelationGetIndexScan.
271  */
272  scan->heapRelation = heapRelation;
273  scan->xs_snapshot = snapshot;
274 
275  /* prepare to fetch index matches from table */
276  scan->xs_heapfetch = table_index_fetch_begin(heapRelation);
277 
278  return scan;
279 }
280 
281 /*
282  * index_beginscan_bitmap - start a scan of an index with amgetbitmap
283  *
284  * As above, caller had better be holding some lock on the parent heap
285  * relation, even though it's not explicitly mentioned here.
286  */
289  Snapshot snapshot,
290  int nkeys)
291 {
292  IndexScanDesc scan;
293 
294  Assert(snapshot != InvalidSnapshot);
295 
296  scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
297 
298  /*
299  * Save additional parameters into the scandesc. Everything else was set
300  * up by RelationGetIndexScan.
301  */
302  scan->xs_snapshot = snapshot;
303 
304  return scan;
305 }
306 
307 /*
308  * index_beginscan_internal --- common code for index_beginscan variants
309  */
310 static IndexScanDesc
312  int nkeys, int norderbys, Snapshot snapshot,
313  ParallelIndexScanDesc pscan, bool temp_snap)
314 {
315  IndexScanDesc scan;
316 
318  CHECK_REL_PROCEDURE(ambeginscan);
319 
320  if (!(indexRelation->rd_indam->ampredlocks))
321  PredicateLockRelation(indexRelation, snapshot);
322 
323  /*
324  * We hold a reference count to the relcache entry throughout the scan.
325  */
326  RelationIncrementReferenceCount(indexRelation);
327 
328  /*
329  * Tell the AM to open a scan.
330  */
331  scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
332  norderbys);
333  /* Initialize information for parallel scan. */
334  scan->parallel_scan = pscan;
335  scan->xs_temp_snap = temp_snap;
336 
337  return scan;
338 }
339 
340 /* ----------------
341  * index_rescan - (re)start a scan of an index
342  *
343  * During a restart, the caller may specify a new set of scankeys and/or
344  * orderbykeys; but the number of keys cannot differ from what index_beginscan
345  * was told. (Later we might relax that to "must not exceed", but currently
346  * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
347  * To restart the scan without changing keys, pass NULL for the key arrays.
348  * (Of course, keys *must* be passed on the first call, unless
349  * scan->numberOfKeys is zero.)
350  * ----------------
351  */
352 void
354  ScanKey keys, int nkeys,
355  ScanKey orderbys, int norderbys)
356 {
357  SCAN_CHECKS;
358  CHECK_SCAN_PROCEDURE(amrescan);
359 
360  Assert(nkeys == scan->numberOfKeys);
361  Assert(norderbys == scan->numberOfOrderBys);
362 
363  /* Release resources (like buffer pins) from table accesses */
364  if (scan->xs_heapfetch)
366 
367  scan->kill_prior_tuple = false; /* for safety */
368  scan->xs_heap_continue = false;
369 
370  scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
371  orderbys, norderbys);
372 }
373 
374 /* ----------------
375  * index_endscan - end a scan
376  * ----------------
377  */
378 void
380 {
381  SCAN_CHECKS;
382  CHECK_SCAN_PROCEDURE(amendscan);
383 
384  /* Release resources (like buffer pins) from table accesses */
385  if (scan->xs_heapfetch)
386  {
388  scan->xs_heapfetch = NULL;
389  }
390 
391  /* End the AM's scan */
392  scan->indexRelation->rd_indam->amendscan(scan);
393 
394  /* Release index refcount acquired by index_beginscan */
396 
397  if (scan->xs_temp_snap)
399 
400  /* Release the scan data structure itself */
401  IndexScanEnd(scan);
402 }
403 
404 /* ----------------
405  * index_markpos - mark a scan position
406  * ----------------
407  */
408 void
410 {
411  SCAN_CHECKS;
412  CHECK_SCAN_PROCEDURE(ammarkpos);
413 
414  scan->indexRelation->rd_indam->ammarkpos(scan);
415 }
416 
417 /* ----------------
418  * index_restrpos - restore a scan position
419  *
420  * NOTE: this only restores the internal scan state of the index AM. See
421  * comments for ExecRestrPos().
422  *
423  * NOTE: For heap, in the presence of HOT chains, mark/restore only works
424  * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
425  * most one returnable tuple in each HOT chain, and so restoring the prior
426  * state at the granularity of the index AM is sufficient. Since the only
427  * current user of mark/restore functionality is nodeMergejoin.c, this
428  * effectively means that merge-join plans only work for MVCC snapshots. This
429  * could be fixed if necessary, but for now it seems unimportant.
430  * ----------------
431  */
432 void
434 {
436 
437  SCAN_CHECKS;
438  CHECK_SCAN_PROCEDURE(amrestrpos);
439 
440  /* release resources (like buffer pins) from table accesses */
441  if (scan->xs_heapfetch)
443 
444  scan->kill_prior_tuple = false; /* for safety */
445  scan->xs_heap_continue = false;
446 
447  scan->indexRelation->rd_indam->amrestrpos(scan);
448 }
449 
450 /*
451  * index_parallelscan_estimate - estimate shared memory for parallel scan
452  *
453  * Currently, we don't pass any information to the AM-specific estimator,
454  * so it can probably only return a constant. In the future, we might need
455  * to pass more information.
456  */
457 Size
459 {
460  Size nbytes;
461 
462  Assert(snapshot != InvalidSnapshot);
463 
465 
466  nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
467  nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
468  nbytes = MAXALIGN(nbytes);
469 
470  /*
471  * If amestimateparallelscan is not provided, assume there is no
472  * AM-specific data needed. (It's hard to believe that could work, but
473  * it's easy enough to cater to it here.)
474  */
475  if (indexRelation->rd_indam->amestimateparallelscan != NULL)
476  nbytes = add_size(nbytes,
477  indexRelation->rd_indam->amestimateparallelscan());
478 
479  return nbytes;
480 }
481 
482 /*
483  * index_parallelscan_initialize - initialize parallel scan
484  *
485  * We initialize both the ParallelIndexScanDesc proper and the AM-specific
486  * information which follows it.
487  *
488  * This function calls access method specific initialization routine to
489  * initialize am specific information. Call this just once in the leader
490  * process; then, individual workers attach via index_beginscan_parallel.
491  */
492 void
493 index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
494  Snapshot snapshot, ParallelIndexScanDesc target)
495 {
496  Size offset;
497 
498  Assert(snapshot != InvalidSnapshot);
499 
501 
502  offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
503  EstimateSnapshotSpace(snapshot));
504  offset = MAXALIGN(offset);
505 
506  target->ps_relid = RelationGetRelid(heapRelation);
507  target->ps_indexid = RelationGetRelid(indexRelation);
508  target->ps_offset = offset;
509  SerializeSnapshot(snapshot, target->ps_snapshot_data);
510 
511  /* aminitparallelscan is optional; assume no-op if not provided by AM */
512  if (indexRelation->rd_indam->aminitparallelscan != NULL)
513  {
514  void *amtarget;
515 
516  amtarget = OffsetToPointer(target, offset);
517  indexRelation->rd_indam->aminitparallelscan(amtarget);
518  }
519 }
520 
521 /* ----------------
522  * index_parallelrescan - (re)start a parallel scan of an index
523  * ----------------
524  */
525 void
527 {
528  SCAN_CHECKS;
529 
530  if (scan->xs_heapfetch)
532 
533  /* amparallelrescan is optional; assume no-op if not provided by AM */
534  if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
536 }
537 
538 /*
539  * index_beginscan_parallel - join parallel index scan
540  *
541  * Caller must be holding suitable locks on the heap and the index.
542  */
544 index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys,
545  int norderbys, ParallelIndexScanDesc pscan)
546 {
547  Snapshot snapshot;
548  IndexScanDesc scan;
549 
550  Assert(RelationGetRelid(heaprel) == pscan->ps_relid);
551  snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
552  RegisterSnapshot(snapshot);
553  scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
554  pscan, true);
555 
556  /*
557  * Save additional parameters into the scandesc. Everything else was set
558  * up by index_beginscan_internal.
559  */
560  scan->heapRelation = heaprel;
561  scan->xs_snapshot = snapshot;
562 
563  /* prepare to fetch index matches from table */
564  scan->xs_heapfetch = table_index_fetch_begin(heaprel);
565 
566  return scan;
567 }
568 
569 /* ----------------
570  * index_getnext_tid - get the next TID from a scan
571  *
572  * The result is the next TID satisfying the scan keys,
573  * or NULL if no more matching tuples exist.
574  * ----------------
575  */
578 {
579  bool found;
580 
581  SCAN_CHECKS;
582  CHECK_SCAN_PROCEDURE(amgettuple);
583 
584  /* XXX: we should assert that a snapshot is pushed or registered */
586 
587  /*
588  * The AM's amgettuple proc finds the next index entry matching the scan
589  * keys, and puts the TID into scan->xs_heaptid. It should also set
590  * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
591  * pay no attention to those fields here.
592  */
593  found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
594 
595  /* Reset kill flag immediately for safety */
596  scan->kill_prior_tuple = false;
597  scan->xs_heap_continue = false;
598 
599  /* If we're out of index entries, we're done */
600  if (!found)
601  {
602  /* release resources (like buffer pins) from table accesses */
603  if (scan->xs_heapfetch)
605 
606  return NULL;
607  }
609 
611 
612  /* Return the TID of the tuple we found. */
613  return &scan->xs_heaptid;
614 }
615 
616 /* ----------------
617  * index_fetch_heap - get the scan's next heap tuple
618  *
619  * The result is a visible heap tuple associated with the index TID most
620  * recently fetched by index_getnext_tid, or NULL if no more matching tuples
621  * exist. (There can be more than one matching tuple because of HOT chains,
622  * although when using an MVCC snapshot it should be impossible for more than
623  * one such tuple to exist.)
624  *
625  * On success, the buffer containing the heap tup is pinned (the pin will be
626  * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
627  * call).
628  *
629  * Note: caller must check scan->xs_recheck, and perform rechecking of the
630  * scan keys if required. We do not do that here because we don't have
631  * enough information to do it efficiently in the general case.
632  * ----------------
633  */
634 bool
636 {
637  bool all_dead = false;
638  bool found;
639 
640  found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
641  scan->xs_snapshot, slot,
642  &scan->xs_heap_continue, &all_dead);
643 
644  if (found)
646 
647  /*
648  * If we scanned a whole HOT chain and found only dead tuples, tell index
649  * AM to kill its entry for that TID (this will take effect in the next
650  * amgettuple call, in index_getnext_tid). We do not do this when in
651  * recovery because it may violate MVCC to do so. See comments in
652  * RelationGetIndexScan().
653  */
654  if (!scan->xactStartedInRecovery)
655  scan->kill_prior_tuple = all_dead;
656 
657  return found;
658 }
659 
660 /* ----------------
661  * index_getnext_slot - get the next tuple from a scan
662  *
663  * The result is true if a tuple satisfying the scan keys and the snapshot was
664  * found, false otherwise. The tuple is stored in the specified slot.
665  *
666  * On success, resources (like buffer pins) are likely to be held, and will be
667  * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
668  * call).
669  *
670  * Note: caller must check scan->xs_recheck, and perform rechecking of the
671  * scan keys if required. We do not do that here because we don't have
672  * enough information to do it efficiently in the general case.
673  * ----------------
674  */
675 bool
677 {
678  for (;;)
679  {
680  if (!scan->xs_heap_continue)
681  {
682  ItemPointer tid;
683 
684  /* Time to fetch the next TID from the index */
685  tid = index_getnext_tid(scan, direction);
686 
687  /* If we're out of index entries, we're done */
688  if (tid == NULL)
689  break;
690 
691  Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
692  }
693 
694  /*
695  * Fetch the next (or only) visible heap tuple for this index entry.
696  * If we don't find anything, loop around and grab the next TID from
697  * the index.
698  */
700  if (index_fetch_heap(scan, slot))
701  return true;
702  }
703 
704  return false;
705 }
706 
707 /* ----------------
708  * index_getbitmap - get all tuples at once from an index scan
709  *
710  * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
711  * Since there's no interlock between the index scan and the eventual heap
712  * access, this is only safe to use with MVCC-based snapshots: the heap
713  * item slot could have been replaced by a newer tuple by the time we get
714  * to it.
715  *
716  * Returns the number of matching tuples found. (Note: this might be only
717  * approximate, so it should only be used for statistical purposes.)
718  * ----------------
719  */
720 int64
722 {
723  int64 ntids;
724 
725  SCAN_CHECKS;
726  CHECK_SCAN_PROCEDURE(amgetbitmap);
727 
728  /* just make sure this is false... */
729  scan->kill_prior_tuple = false;
730 
731  /*
732  * have the am's getbitmap proc do all the work.
733  */
734  ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
735 
737 
738  return ntids;
739 }
740 
741 /* ----------------
742  * index_bulk_delete - do mass deletion of index entries
743  *
744  * callback routine tells whether a given main-heap tuple is
745  * to be deleted
746  *
747  * return value is an optional palloc'd struct of statistics
748  * ----------------
749  */
752  IndexBulkDeleteResult *istat,
754  void *callback_state)
755 {
756  Relation indexRelation = info->index;
757 
759  CHECK_REL_PROCEDURE(ambulkdelete);
760 
761  return indexRelation->rd_indam->ambulkdelete(info, istat,
762  callback, callback_state);
763 }
764 
765 /* ----------------
766  * index_vacuum_cleanup - do post-deletion cleanup of an index
767  *
768  * return value is an optional palloc'd struct of statistics
769  * ----------------
770  */
773  IndexBulkDeleteResult *istat)
774 {
775  Relation indexRelation = info->index;
776 
778  CHECK_REL_PROCEDURE(amvacuumcleanup);
779 
780  return indexRelation->rd_indam->amvacuumcleanup(info, istat);
781 }
782 
783 /* ----------------
784  * index_can_return
785  *
786  * Does the index access method support index-only scans for the given
787  * column?
788  * ----------------
789  */
790 bool
791 index_can_return(Relation indexRelation, int attno)
792 {
794 
795  /* amcanreturn is optional; assume false if not provided by AM */
796  if (indexRelation->rd_indam->amcanreturn == NULL)
797  return false;
798 
799  return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
800 }
801 
802 /* ----------------
803  * index_getprocid
804  *
805  * Index access methods typically require support routines that are
806  * not directly the implementation of any WHERE-clause query operator
807  * and so cannot be kept in pg_amop. Instead, such routines are kept
808  * in pg_amproc. These registered procedure OIDs are assigned numbers
809  * according to a convention established by the access method.
810  * The general index code doesn't know anything about the routines
811  * involved; it just builds an ordered list of them for
812  * each attribute on which an index is defined.
813  *
814  * As of Postgres 8.3, support routines within an operator family
815  * are further subdivided by the "left type" and "right type" of the
816  * query operator(s) that they support. The "default" functions for a
817  * particular indexed attribute are those with both types equal to
818  * the index opclass' opcintype (note that this is subtly different
819  * from the indexed attribute's own type: it may be a binary-compatible
820  * type instead). Only the default functions are stored in relcache
821  * entries --- access methods can use the syscache to look up non-default
822  * functions.
823  *
824  * This routine returns the requested default procedure OID for a
825  * particular indexed attribute.
826  * ----------------
827  */
831  uint16 procnum)
832 {
833  RegProcedure *loc;
834  int nproc;
835  int procindex;
836 
837  nproc = irel->rd_indam->amsupport;
838 
839  Assert(procnum > 0 && procnum <= (uint16) nproc);
840 
841  procindex = (nproc * (attnum - 1)) + (procnum - 1);
842 
843  loc = irel->rd_support;
844 
845  Assert(loc != NULL);
846 
847  return loc[procindex];
848 }
849 
850 /* ----------------
851  * index_getprocinfo
852  *
853  * This routine allows index AMs to keep fmgr lookup info for
854  * support procs in the relcache. As above, only the "default"
855  * functions for any particular indexed attribute are cached.
856  *
857  * Note: the return value points into cached data that will be lost during
858  * any relcache rebuild! Therefore, either use the callinfo right away,
859  * or save it only after having acquired some type of lock on the index rel.
860  * ----------------
861  */
862 FmgrInfo *
865  uint16 procnum)
866 {
867  FmgrInfo *locinfo;
868  int nproc;
869  int optsproc;
870  int procindex;
871 
872  nproc = irel->rd_indam->amsupport;
873  optsproc = irel->rd_indam->amoptsprocnum;
874 
875  Assert(procnum > 0 && procnum <= (uint16) nproc);
876 
877  procindex = (nproc * (attnum - 1)) + (procnum - 1);
878 
879  locinfo = irel->rd_supportinfo;
880 
881  Assert(locinfo != NULL);
882 
883  locinfo += procindex;
884 
885  /* Initialize the lookup info if first time through */
886  if (locinfo->fn_oid == InvalidOid)
887  {
888  RegProcedure *loc = irel->rd_support;
889  RegProcedure procId;
890 
891  Assert(loc != NULL);
892 
893  procId = loc[procindex];
894 
895  /*
896  * Complain if function was not found during IndexSupportInitialize.
897  * This should not happen unless the system tables contain bogus
898  * entries for the index opclass. (If an AM wants to allow a support
899  * function to be optional, it can use index_getprocid.)
900  */
901  if (!RegProcedureIsValid(procId))
902  elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
903  procnum, attnum, RelationGetRelationName(irel));
904 
905  fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
906 
907  if (procnum != optsproc)
908  {
909  /* Initialize locinfo->fn_expr with opclass options Const */
910  bytea **attoptions = RelationGetIndexAttOptions(irel, false);
912 
913  set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
914 
915  MemoryContextSwitchTo(oldcxt);
916  }
917  }
918 
919  return locinfo;
920 }
921 
922 /* ----------------
923  * index_store_float8_orderby_distances
924  *
925  * Convert AM distance function's results (that can be inexact)
926  * to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
927  * for a possible recheck.
928  * ----------------
929  */
930 void
932  IndexOrderByDistance *distances,
933  bool recheckOrderBy)
934 {
935  int i;
936 
937  Assert(distances || !recheckOrderBy);
938 
939  scan->xs_recheckorderby = recheckOrderBy;
940 
941  for (i = 0; i < scan->numberOfOrderBys; i++)
942  {
943  if (orderByTypes[i] == FLOAT8OID)
944  {
945 #ifndef USE_FLOAT8_BYVAL
946  /* must free any old value to avoid memory leakage */
947  if (!scan->xs_orderbynulls[i])
949 #endif
950  if (distances && !distances[i].isnull)
951  {
952  scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
953  scan->xs_orderbynulls[i] = false;
954  }
955  else
956  {
957  scan->xs_orderbyvals[i] = (Datum) 0;
958  scan->xs_orderbynulls[i] = true;
959  }
960  }
961  else if (orderByTypes[i] == FLOAT4OID)
962  {
963  /* convert distance function's result to ORDER BY type */
964  if (distances && !distances[i].isnull)
965  {
966  scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
967  scan->xs_orderbynulls[i] = false;
968  }
969  else
970  {
971  scan->xs_orderbyvals[i] = (Datum) 0;
972  scan->xs_orderbynulls[i] = true;
973  }
974  }
975  else
976  {
977  /*
978  * If the ordering operator's return value is anything else, we
979  * don't know how to convert the float8 bound calculated by the
980  * distance function to that. The executor won't actually need
981  * the order by values we return here, if there are no lossy
982  * results, so only insist on converting if the *recheck flag is
983  * set.
984  */
985  if (scan->xs_recheckorderby)
986  elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
987  scan->xs_orderbynulls[i] = true;
988  }
989  }
990 }
991 
992 /* ----------------
993  * index_opclass_options
994  *
995  * Parse opclass-specific options for index column.
996  * ----------------
997  */
998 bytea *
1000  bool validate)
1001 {
1002  int amoptsprocnum = indrel->rd_indam->amoptsprocnum;
1003  Oid procid = InvalidOid;
1004  FmgrInfo *procinfo;
1005  local_relopts relopts;
1006 
1007  /* fetch options support procedure if specified */
1008  if (amoptsprocnum != 0)
1009  procid = index_getprocid(indrel, attnum, amoptsprocnum);
1010 
1011  if (!OidIsValid(procid))
1012  {
1013  Oid opclass;
1014  Datum indclassDatum;
1015  oidvector *indclass;
1016 
1017  if (!DatumGetPointer(attoptions))
1018  return NULL; /* ok, no options, no procedure */
1019 
1020  /*
1021  * Report an error if the opclass's options-parsing procedure does not
1022  * exist but the opclass options are specified.
1023  */
1024  indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indrel->rd_indextuple,
1025  Anum_pg_index_indclass);
1026  indclass = (oidvector *) DatumGetPointer(indclassDatum);
1027  opclass = indclass->values[attnum - 1];
1028 
1029  ereport(ERROR,
1030  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1031  errmsg("operator class %s has no options",
1032  generate_opclass_name(opclass))));
1033  }
1034 
1035  init_local_reloptions(&relopts, 0);
1036 
1037  procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
1038 
1039  (void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
1040 
1041  return build_local_reloptions(&relopts, attoptions, validate);
1042 }
int16 AttrNumber
Definition: attnum.h:21
#define InvalidBlockNumber
Definition: block.h:33
static Datum values[MAXATTR]
Definition: bootstrap.c:152
#define OffsetToPointer(base, offset)
Definition: c.h:759
unsigned short uint16
Definition: c.h:492
#define RegProcedureIsValid(p)
Definition: c.h:764
#define MAXALIGN(LEN)
Definition: c.h:798
regproc RegProcedure
Definition: c.h:637
float float4
Definition: c.h:616
#define OidIsValid(objectId)
Definition: c.h:762
size_t Size
Definition: c.h:592
int errcode(int sqlerrcode)
Definition: elog.c:859
int errmsg(const char *fmt,...)
Definition: elog.c:1072
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:224
#define ereport(elevel,...)
Definition: elog.h:149
void set_fn_opclass_options(FmgrInfo *flinfo, bytea *options)
Definition: fmgr.c:2070
void fmgr_info_cxt(Oid functionId, FmgrInfo *finfo, MemoryContext mcxt)
Definition: fmgr.c:137
Datum Float8GetDatum(float8 X)
Definition: fmgr.c:1816
#define FunctionCall1(flinfo, arg1)
Definition: fmgr.h:660
void IndexScanEnd(IndexScanDesc scan)
Definition: genam.c:142
bool(* IndexBulkDeleteCallback)(ItemPointer itemptr, void *state)
Definition: genam.h:87
IndexUniqueCheck
Definition: genam.h:116
bool index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
Definition: indexam.c:676
IndexBulkDeleteResult * index_vacuum_cleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *istat)
Definition: indexam.c:772
Size index_parallelscan_estimate(Relation indexRelation, Snapshot snapshot)
Definition: indexam.c:458
#define CHECK_REL_PROCEDURE(pname)
Definition: indexam.c:93
static void validate_relation_kind(Relation r)
Definition: indexam.c:197
bool index_insert(Relation indexRelation, Datum *values, bool *isnull, ItemPointer heap_t_ctid, Relation heapRelation, IndexUniqueCheck checkUnique, bool indexUnchanged, IndexInfo *indexInfo)
Definition: indexam.c:213
void index_restrpos(IndexScanDesc scan)
Definition: indexam.c:433
static IndexScanDesc index_beginscan_internal(Relation indexRelation, int nkeys, int norderbys, Snapshot snapshot, ParallelIndexScanDesc pscan, bool temp_snap)
Definition: indexam.c:311
IndexScanDesc index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys, int norderbys, ParallelIndexScanDesc pscan)
Definition: indexam.c:544
IndexScanDesc index_beginscan_bitmap(Relation indexRelation, Snapshot snapshot, int nkeys)
Definition: indexam.c:288
void index_insert_cleanup(Relation indexRelation, IndexInfo *indexInfo)
Definition: indexam.c:241
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:177
bool index_can_return(Relation indexRelation, int attno)
Definition: indexam.c:791
ItemPointer index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
Definition: indexam.c:577
FmgrInfo * index_getprocinfo(Relation irel, AttrNumber attnum, uint16 procnum)
Definition: indexam.c:863
IndexScanDesc index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, int norderbys)
Definition: indexam.c:257
RegProcedure index_getprocid(Relation irel, AttrNumber attnum, uint16 procnum)
Definition: indexam.c:829
bool index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
Definition: indexam.c:635
void index_markpos(IndexScanDesc scan)
Definition: indexam.c:409
Relation try_index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:152
void index_endscan(IndexScanDesc scan)
Definition: indexam.c:379
#define RELATION_CHECKS
Definition: indexam.c:75
IndexBulkDeleteResult * index_bulk_delete(IndexVacuumInfo *info, IndexBulkDeleteResult *istat, IndexBulkDeleteCallback callback, void *callback_state)
Definition: indexam.c:751
void index_parallelscan_initialize(Relation heapRelation, Relation indexRelation, Snapshot snapshot, ParallelIndexScanDesc target)
Definition: indexam.c:493
Relation index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:133
bytea * index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions, bool validate)
Definition: indexam.c:999
int64 index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
Definition: indexam.c:721
void index_parallelrescan(IndexScanDesc scan)
Definition: indexam.c:526
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:353
#define CHECK_SCAN_PROCEDURE(pname)
Definition: indexam.c:100
#define SCAN_CHECKS
Definition: indexam.c:86
void index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes, IndexOrderByDistance *distances, bool recheckOrderBy)
Definition: indexam.c:931
static struct @150 value
int i
Definition: isn.c:73
bool ItemPointerEquals(ItemPointer pointer1, ItemPointer pointer2)
Definition: itemptr.c:35
static bool ItemPointerIsValid(const ItemPointerData *pointer)
Definition: itemptr.h:83
Assert(fmt[strlen(fmt) - 1] !='\n')
void UnlockRelationId(LockRelId *relid, LOCKMODE lockmode)
Definition: lmgr.c:212
#define MAX_LOCKMODES
Definition: lock.h:82
int LOCKMODE
Definition: lockdefs.h:26
#define NoLock
Definition: lockdefs.h:34
void pfree(void *pointer)
Definition: mcxt.c:1508
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:124
int16 attnum
Definition: pg_attribute.h:74
#define pgstat_count_index_tuples(rel, n)
Definition: pgstat.h:630
#define pgstat_count_heap_fetch(rel)
Definition: pgstat.h:620
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:322
static Datum Float4GetDatum(float4 X)
Definition: postgres.h:475
uintptr_t Datum
Definition: postgres.h:64
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:312
#define InvalidOid
Definition: postgres_ext.h:36
unsigned int Oid
Definition: postgres_ext.h:31
void CheckForSerializableConflictIn(Relation relation, ItemPointer tid, BlockNumber blkno)
Definition: predicate.c:4316
void PredicateLockRelation(Relation relation, Snapshot snapshot)
Definition: predicate.c:2556
#define RelationGetRelid(relation)
Definition: rel.h:505
#define RelationGetRelationName(relation)
Definition: rel.h:539
void RelationDecrementReferenceCount(Relation rel)
Definition: relcache.c:2166
void RelationIncrementReferenceCount(Relation rel)
Definition: relcache.c:2153
bytea ** RelationGetIndexAttOptions(Relation relation, bool copy)
Definition: relcache.c:5873
void RelationClose(Relation relation)
Definition: relcache.c:2186
void init_local_reloptions(local_relopts *relopts, Size relopt_struct_size)
Definition: reloptions.c:734
void * build_local_reloptions(local_relopts *relopts, Datum options, bool validate)
Definition: reloptions.c:1945
char * generate_opclass_name(Oid opclass)
Definition: ruleutils.c:11857
ScanDirection
Definition: sdir.h:25
Size add_size(Size s1, Size s2)
Definition: shmem.c:493
TransactionId RecentXmin
Definition: snapmgr.c:99
void SerializeSnapshot(Snapshot snapshot, char *start_address)
Definition: snapmgr.c:1716
void UnregisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:836
Snapshot RestoreSnapshot(char *start_address)
Definition: snapmgr.c:1775
Snapshot RegisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:794
Size EstimateSnapshotSpace(Snapshot snapshot)
Definition: snapmgr.c:1692
#define IsMVCCSnapshot(snapshot)
Definition: snapmgr.h:62
#define InvalidSnapshot
Definition: snapshot.h:123
Relation try_relation_open(Oid relationId, LOCKMODE lockmode)
Definition: relation.c:88
Relation relation_open(Oid relationId, LOCKMODE lockmode)
Definition: relation.c:47
Definition: fmgr.h:57
Oid fn_oid
Definition: fmgr.h:59
amvacuumcleanup_function amvacuumcleanup
Definition: amapi.h:271
amestimateparallelscan_function amestimateparallelscan
Definition: amapi.h:288
amrestrpos_function amrestrpos
Definition: amapi.h:285
aminsert_function aminsert
Definition: amapi.h:268
amendscan_function amendscan
Definition: amapi.h:283
uint16 amoptsprocnum
Definition: amapi.h:221
amparallelrescan_function amparallelrescan
Definition: amapi.h:290
bool ampredlocks
Definition: amapi.h:243
uint16 amsupport
Definition: amapi.h:219
amgettuple_function amgettuple
Definition: amapi.h:281
amcanreturn_function amcanreturn
Definition: amapi.h:272
amgetbitmap_function amgetbitmap
Definition: amapi.h:282
ambulkdelete_function ambulkdelete
Definition: amapi.h:270
ammarkpos_function ammarkpos
Definition: amapi.h:284
ambeginscan_function ambeginscan
Definition: amapi.h:279
amrescan_function amrescan
Definition: amapi.h:280
aminitparallelscan_function aminitparallelscan
Definition: amapi.h:289
aminsertcleanup_function aminsertcleanup
Definition: amapi.h:269
void * ii_AmCache
Definition: execnodes.h:207
bool xs_heap_continue
Definition: relscan.h:148
struct ParallelIndexScanDescData * parallel_scan
Definition: relscan.h:166
bool * xs_orderbynulls
Definition: relscan.h:162
IndexFetchTableData * xs_heapfetch
Definition: relscan.h:150
int numberOfOrderBys
Definition: relscan.h:121
bool xactStartedInRecovery
Definition: relscan.h:130
bool xs_recheckorderby
Definition: relscan.h:163
bool kill_prior_tuple
Definition: relscan.h:128
Relation indexRelation
Definition: relscan.h:118
ItemPointerData xs_heaptid
Definition: relscan.h:147
struct SnapshotData * xs_snapshot
Definition: relscan.h:119
Relation heapRelation
Definition: relscan.h:117
Datum * xs_orderbyvals
Definition: relscan.h:161
Relation index
Definition: genam.h:46
LockRelId lockRelId
Definition: rel.h:46
Definition: rel.h:39
char ps_snapshot_data[FLEXIBLE_ARRAY_MEMBER]
Definition: relscan.h:175
struct IndexAmRoutine * rd_indam
Definition: rel.h:206
LockInfoData rd_lockInfo
Definition: rel.h:114
RegProcedure * rd_support
Definition: rel.h:209
struct HeapTupleData * rd_indextuple
Definition: rel.h:194
MemoryContext rd_indexcxt
Definition: rel.h:204
struct FmgrInfo * rd_supportinfo
Definition: rel.h:210
Form_pg_class rd_rel
Definition: rel.h:111
Definition: c.h:713
Oid values[FLEXIBLE_ARRAY_MEMBER]
Definition: c.h:720
Definition: c.h:674
Datum SysCacheGetAttrNotNull(int cacheId, HeapTuple tup, AttrNumber attributeNumber)
Definition: syscache.c:510
static IndexFetchTableData * table_index_fetch_begin(Relation rel)
Definition: tableam.h:1182
static void table_index_fetch_reset(struct IndexFetchTableData *scan)
Definition: tableam.h:1192
static void table_index_fetch_end(struct IndexFetchTableData *scan)
Definition: tableam.h:1201
static bool table_index_fetch_tuple(struct IndexFetchTableData *scan, ItemPointer tid, Snapshot snapshot, TupleTableSlot *slot, bool *call_again, bool *all_dead)
Definition: tableam.h:1231
static void callback(struct sockaddr *addr, struct sockaddr *mask, void *unused)
Definition: test_ifaddrs.c:46
#define TransactionIdIsValid(xid)
Definition: transam.h:41