PostgreSQL Source Code  git master
indexam.c
Go to the documentation of this file.
1 /*-------------------------------------------------------------------------
2  *
3  * indexam.c
4  * general index access method routines
5  *
6  * Portions Copyright (c) 1996-2021, 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/heapam.h"
48 #include "access/reloptions.h"
49 #include "access/relscan.h"
50 #include "access/tableam.h"
51 #include "access/transam.h"
52 #include "access/xlog.h"
53 #include "catalog/index.h"
54 #include "catalog/pg_amproc.h"
55 #include "catalog/pg_type.h"
56 #include "commands/defrem.h"
57 #include "nodes/makefuncs.h"
58 #include "pgstat.h"
59 #include "storage/bufmgr.h"
60 #include "storage/lmgr.h"
61 #include "storage/predicate.h"
62 #include "utils/ruleutils.h"
63 #include "utils/snapmgr.h"
64 #include "utils/syscache.h"
65 
66 
67 /* ----------------------------------------------------------------
68  * macros used in index_ routines
69  *
70  * Note: the ReindexIsProcessingIndex() check in RELATION_CHECKS is there
71  * to check that we don't try to scan or do retail insertions into an index
72  * that is currently being rebuilt or pending rebuild. This helps to catch
73  * things that don't work when reindexing system catalogs. The assertion
74  * doesn't prevent the actual rebuild because we don't use RELATION_CHECKS
75  * when calling the index AM's ambuild routine, and there is no reason for
76  * ambuild to call its subsidiary routines through this file.
77  * ----------------------------------------------------------------
78  */
79 #define RELATION_CHECKS \
80 ( \
81  AssertMacro(RelationIsValid(indexRelation)), \
82  AssertMacro(PointerIsValid(indexRelation->rd_indam)), \
83  AssertMacro(!ReindexIsProcessingIndex(RelationGetRelid(indexRelation))) \
84 )
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 
111 
112 /* ----------------------------------------------------------------
113  * index_ interface functions
114  * ----------------------------------------------------------------
115  */
116 
117 /* ----------------
118  * index_open - open an index relation by relation OID
119  *
120  * If lockmode is not "NoLock", the specified kind of lock is
121  * obtained on the index. (Generally, NoLock should only be
122  * used if the caller knows it has some appropriate lock on the
123  * index already.)
124  *
125  * An error is raised if the index does not exist.
126  *
127  * This is a convenience routine adapted for indexscan use.
128  * Some callers may prefer to use relation_open directly.
129  * ----------------
130  */
131 Relation
132 index_open(Oid relationId, LOCKMODE lockmode)
133 {
134  Relation r;
135 
136  r = relation_open(relationId, lockmode);
137 
138  if (r->rd_rel->relkind != RELKIND_INDEX &&
139  r->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
140  ereport(ERROR,
141  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
142  errmsg("\"%s\" is not an index",
144 
145  return r;
146 }
147 
148 /* ----------------
149  * index_close - close an index relation
150  *
151  * If lockmode is not "NoLock", we then release the specified lock.
152  *
153  * Note that it is often sensible to hold a lock beyond index_close;
154  * in that case, the lock is released automatically at xact end.
155  * ----------------
156  */
157 void
158 index_close(Relation relation, LOCKMODE lockmode)
159 {
160  LockRelId relid = relation->rd_lockInfo.lockRelId;
161 
162  Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
163 
164  /* The relcache does the real work... */
165  RelationClose(relation);
166 
167  if (lockmode != NoLock)
168  UnlockRelationId(&relid, lockmode);
169 }
170 
171 /* ----------------
172  * index_insert - insert an index tuple into a relation
173  * ----------------
174  */
175 bool
176 index_insert(Relation indexRelation,
177  Datum *values,
178  bool *isnull,
179  ItemPointer heap_t_ctid,
180  Relation heapRelation,
181  IndexUniqueCheck checkUnique,
182  bool indexUnchanged,
183  IndexInfo *indexInfo)
184 {
186  CHECK_REL_PROCEDURE(aminsert);
187 
188  if (!(indexRelation->rd_indam->ampredlocks))
189  CheckForSerializableConflictIn(indexRelation,
190  (ItemPointer) NULL,
192 
193  return indexRelation->rd_indam->aminsert(indexRelation, values, isnull,
194  heap_t_ctid, heapRelation,
195  checkUnique, indexUnchanged,
196  indexInfo);
197 }
198 
199 /*
200  * index_beginscan - start a scan of an index with amgettuple
201  *
202  * Caller must be holding suitable locks on the heap and the index.
203  */
206  Relation indexRelation,
207  Snapshot snapshot,
208  int nkeys, int norderbys)
209 {
210  IndexScanDesc scan;
211 
212  scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
213 
214  /*
215  * Save additional parameters into the scandesc. Everything else was set
216  * up by RelationGetIndexScan.
217  */
218  scan->heapRelation = heapRelation;
219  scan->xs_snapshot = snapshot;
220 
221  /* prepare to fetch index matches from table */
222  scan->xs_heapfetch = table_index_fetch_begin(heapRelation);
223 
224  return scan;
225 }
226 
227 /*
228  * index_beginscan_bitmap - start a scan of an index with amgetbitmap
229  *
230  * As above, caller had better be holding some lock on the parent heap
231  * relation, even though it's not explicitly mentioned here.
232  */
235  Snapshot snapshot,
236  int nkeys)
237 {
238  IndexScanDesc scan;
239 
240  scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
241 
242  /*
243  * Save additional parameters into the scandesc. Everything else was set
244  * up by RelationGetIndexScan.
245  */
246  scan->xs_snapshot = snapshot;
247 
248  return scan;
249 }
250 
251 /*
252  * index_beginscan_internal --- common code for index_beginscan variants
253  */
254 static IndexScanDesc
256  int nkeys, int norderbys, Snapshot snapshot,
257  ParallelIndexScanDesc pscan, bool temp_snap)
258 {
259  IndexScanDesc scan;
260 
262  CHECK_REL_PROCEDURE(ambeginscan);
263 
264  if (!(indexRelation->rd_indam->ampredlocks))
265  PredicateLockRelation(indexRelation, snapshot);
266 
267  /*
268  * We hold a reference count to the relcache entry throughout the scan.
269  */
270  RelationIncrementReferenceCount(indexRelation);
271 
272  /*
273  * Tell the AM to open a scan.
274  */
275  scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
276  norderbys);
277  /* Initialize information for parallel scan. */
278  scan->parallel_scan = pscan;
279  scan->xs_temp_snap = temp_snap;
280 
281  return scan;
282 }
283 
284 /* ----------------
285  * index_rescan - (re)start a scan of an index
286  *
287  * During a restart, the caller may specify a new set of scankeys and/or
288  * orderbykeys; but the number of keys cannot differ from what index_beginscan
289  * was told. (Later we might relax that to "must not exceed", but currently
290  * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
291  * To restart the scan without changing keys, pass NULL for the key arrays.
292  * (Of course, keys *must* be passed on the first call, unless
293  * scan->numberOfKeys is zero.)
294  * ----------------
295  */
296 void
298  ScanKey keys, int nkeys,
299  ScanKey orderbys, int norderbys)
300 {
301  SCAN_CHECKS;
302  CHECK_SCAN_PROCEDURE(amrescan);
303 
304  Assert(nkeys == scan->numberOfKeys);
305  Assert(norderbys == scan->numberOfOrderBys);
306 
307  /* Release resources (like buffer pins) from table accesses */
308  if (scan->xs_heapfetch)
310 
311  scan->kill_prior_tuple = false; /* for safety */
312  scan->xs_heap_continue = false;
313 
314  scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
315  orderbys, norderbys);
316 }
317 
318 /* ----------------
319  * index_endscan - end a scan
320  * ----------------
321  */
322 void
324 {
325  SCAN_CHECKS;
326  CHECK_SCAN_PROCEDURE(amendscan);
327 
328  /* Release resources (like buffer pins) from table accesses */
329  if (scan->xs_heapfetch)
330  {
332  scan->xs_heapfetch = NULL;
333  }
334 
335  /* End the AM's scan */
336  scan->indexRelation->rd_indam->amendscan(scan);
337 
338  /* Release index refcount acquired by index_beginscan */
340 
341  if (scan->xs_temp_snap)
343 
344  /* Release the scan data structure itself */
345  IndexScanEnd(scan);
346 }
347 
348 /* ----------------
349  * index_markpos - mark a scan position
350  * ----------------
351  */
352 void
354 {
355  SCAN_CHECKS;
356  CHECK_SCAN_PROCEDURE(ammarkpos);
357 
358  scan->indexRelation->rd_indam->ammarkpos(scan);
359 }
360 
361 /* ----------------
362  * index_restrpos - restore a scan position
363  *
364  * NOTE: this only restores the internal scan state of the index AM. See
365  * comments for ExecRestrPos().
366  *
367  * NOTE: For heap, in the presence of HOT chains, mark/restore only works
368  * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
369  * most one returnable tuple in each HOT chain, and so restoring the prior
370  * state at the granularity of the index AM is sufficient. Since the only
371  * current user of mark/restore functionality is nodeMergejoin.c, this
372  * effectively means that merge-join plans only work for MVCC snapshots. This
373  * could be fixed if necessary, but for now it seems unimportant.
374  * ----------------
375  */
376 void
378 {
380 
381  SCAN_CHECKS;
382  CHECK_SCAN_PROCEDURE(amrestrpos);
383 
384  /* release resources (like buffer pins) from table accesses */
385  if (scan->xs_heapfetch)
387 
388  scan->kill_prior_tuple = false; /* for safety */
389  scan->xs_heap_continue = false;
390 
391  scan->indexRelation->rd_indam->amrestrpos(scan);
392 }
393 
394 /*
395  * index_parallelscan_estimate - estimate shared memory for parallel scan
396  *
397  * Currently, we don't pass any information to the AM-specific estimator,
398  * so it can probably only return a constant. In the future, we might need
399  * to pass more information.
400  */
401 Size
403 {
404  Size nbytes;
405 
407 
408  nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
409  nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
410  nbytes = MAXALIGN(nbytes);
411 
412  /*
413  * If amestimateparallelscan is not provided, assume there is no
414  * AM-specific data needed. (It's hard to believe that could work, but
415  * it's easy enough to cater to it here.)
416  */
417  if (indexRelation->rd_indam->amestimateparallelscan != NULL)
418  nbytes = add_size(nbytes,
419  indexRelation->rd_indam->amestimateparallelscan());
420 
421  return nbytes;
422 }
423 
424 /*
425  * index_parallelscan_initialize - initialize parallel scan
426  *
427  * We initialize both the ParallelIndexScanDesc proper and the AM-specific
428  * information which follows it.
429  *
430  * This function calls access method specific initialization routine to
431  * initialize am specific information. Call this just once in the leader
432  * process; then, individual workers attach via index_beginscan_parallel.
433  */
434 void
435 index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
436  Snapshot snapshot, ParallelIndexScanDesc target)
437 {
438  Size offset;
439 
441 
442  offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
443  EstimateSnapshotSpace(snapshot));
444  offset = MAXALIGN(offset);
445 
446  target->ps_relid = RelationGetRelid(heapRelation);
447  target->ps_indexid = RelationGetRelid(indexRelation);
448  target->ps_offset = offset;
449  SerializeSnapshot(snapshot, target->ps_snapshot_data);
450 
451  /* aminitparallelscan is optional; assume no-op if not provided by AM */
452  if (indexRelation->rd_indam->aminitparallelscan != NULL)
453  {
454  void *amtarget;
455 
456  amtarget = OffsetToPointer(target, offset);
457  indexRelation->rd_indam->aminitparallelscan(amtarget);
458  }
459 }
460 
461 /* ----------------
462  * index_parallelrescan - (re)start a parallel scan of an index
463  * ----------------
464  */
465 void
467 {
468  SCAN_CHECKS;
469 
470  if (scan->xs_heapfetch)
472 
473  /* amparallelrescan is optional; assume no-op if not provided by AM */
474  if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
476 }
477 
478 /*
479  * index_beginscan_parallel - join parallel index scan
480  *
481  * Caller must be holding suitable locks on the heap and the index.
482  */
484 index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys,
485  int norderbys, ParallelIndexScanDesc pscan)
486 {
487  Snapshot snapshot;
488  IndexScanDesc scan;
489 
490  Assert(RelationGetRelid(heaprel) == pscan->ps_relid);
491  snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
492  RegisterSnapshot(snapshot);
493  scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
494  pscan, true);
495 
496  /*
497  * Save additional parameters into the scandesc. Everything else was set
498  * up by index_beginscan_internal.
499  */
500  scan->heapRelation = heaprel;
501  scan->xs_snapshot = snapshot;
502 
503  /* prepare to fetch index matches from table */
504  scan->xs_heapfetch = table_index_fetch_begin(heaprel);
505 
506  return scan;
507 }
508 
509 /* ----------------
510  * index_getnext_tid - get the next TID from a scan
511  *
512  * The result is the next TID satisfying the scan keys,
513  * or NULL if no more matching tuples exist.
514  * ----------------
515  */
518 {
519  bool found;
520 
521  SCAN_CHECKS;
522  CHECK_SCAN_PROCEDURE(amgettuple);
523 
524  /* XXX: we should assert that a snapshot is pushed or registered */
526 
527  /*
528  * The AM's amgettuple proc finds the next index entry matching the scan
529  * keys, and puts the TID into scan->xs_heaptid. It should also set
530  * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
531  * pay no attention to those fields here.
532  */
533  found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
534 
535  /* Reset kill flag immediately for safety */
536  scan->kill_prior_tuple = false;
537  scan->xs_heap_continue = false;
538 
539  /* If we're out of index entries, we're done */
540  if (!found)
541  {
542  /* release resources (like buffer pins) from table accesses */
543  if (scan->xs_heapfetch)
545 
546  return NULL;
547  }
549 
551 
552  /* Return the TID of the tuple we found. */
553  return &scan->xs_heaptid;
554 }
555 
556 /* ----------------
557  * index_fetch_heap - get the scan's next heap tuple
558  *
559  * The result is a visible heap tuple associated with the index TID most
560  * recently fetched by index_getnext_tid, or NULL if no more matching tuples
561  * exist. (There can be more than one matching tuple because of HOT chains,
562  * although when using an MVCC snapshot it should be impossible for more than
563  * one such tuple to exist.)
564  *
565  * On success, the buffer containing the heap tup is pinned (the pin will be
566  * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
567  * call).
568  *
569  * Note: caller must check scan->xs_recheck, and perform rechecking of the
570  * scan keys if required. We do not do that here because we don't have
571  * enough information to do it efficiently in the general case.
572  * ----------------
573  */
574 bool
576 {
577  bool all_dead = false;
578  bool found;
579 
580  found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
581  scan->xs_snapshot, slot,
582  &scan->xs_heap_continue, &all_dead);
583 
584  if (found)
586 
587  /*
588  * If we scanned a whole HOT chain and found only dead tuples, tell index
589  * AM to kill its entry for that TID (this will take effect in the next
590  * amgettuple call, in index_getnext_tid). We do not do this when in
591  * recovery because it may violate MVCC to do so. See comments in
592  * RelationGetIndexScan().
593  */
594  if (!scan->xactStartedInRecovery)
595  scan->kill_prior_tuple = all_dead;
596 
597  return found;
598 }
599 
600 /* ----------------
601  * index_getnext_slot - get the next tuple from a scan
602  *
603  * The result is true if a tuple satisfying the scan keys and the snapshot was
604  * found, false otherwise. The tuple is stored in the specified slot.
605  *
606  * On success, resources (like buffer pins) are likely to be held, and will be
607  * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
608  * call).
609  *
610  * Note: caller must check scan->xs_recheck, and perform rechecking of the
611  * scan keys if required. We do not do that here because we don't have
612  * enough information to do it efficiently in the general case.
613  * ----------------
614  */
615 bool
617 {
618  for (;;)
619  {
620  if (!scan->xs_heap_continue)
621  {
622  ItemPointer tid;
623 
624  /* Time to fetch the next TID from the index */
625  tid = index_getnext_tid(scan, direction);
626 
627  /* If we're out of index entries, we're done */
628  if (tid == NULL)
629  break;
630 
631  Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
632  }
633 
634  /*
635  * Fetch the next (or only) visible heap tuple for this index entry.
636  * If we don't find anything, loop around and grab the next TID from
637  * the index.
638  */
640  if (index_fetch_heap(scan, slot))
641  return true;
642  }
643 
644  return false;
645 }
646 
647 /* ----------------
648  * index_getbitmap - get all tuples at once from an index scan
649  *
650  * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
651  * Since there's no interlock between the index scan and the eventual heap
652  * access, this is only safe to use with MVCC-based snapshots: the heap
653  * item slot could have been replaced by a newer tuple by the time we get
654  * to it.
655  *
656  * Returns the number of matching tuples found. (Note: this might be only
657  * approximate, so it should only be used for statistical purposes.)
658  * ----------------
659  */
660 int64
662 {
663  int64 ntids;
664 
665  SCAN_CHECKS;
666  CHECK_SCAN_PROCEDURE(amgetbitmap);
667 
668  /* just make sure this is false... */
669  scan->kill_prior_tuple = false;
670 
671  /*
672  * have the am's getbitmap proc do all the work.
673  */
674  ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
675 
677 
678  return ntids;
679 }
680 
681 /* ----------------
682  * index_bulk_delete - do mass deletion of index entries
683  *
684  * callback routine tells whether a given main-heap tuple is
685  * to be deleted
686  *
687  * return value is an optional palloc'd struct of statistics
688  * ----------------
689  */
692  IndexBulkDeleteResult *stats,
694  void *callback_state)
695 {
696  Relation indexRelation = info->index;
697 
699  CHECK_REL_PROCEDURE(ambulkdelete);
700 
701  return indexRelation->rd_indam->ambulkdelete(info, stats,
702  callback, callback_state);
703 }
704 
705 /* ----------------
706  * index_vacuum_cleanup - do post-deletion cleanup of an index
707  *
708  * return value is an optional palloc'd struct of statistics
709  * ----------------
710  */
713  IndexBulkDeleteResult *stats)
714 {
715  Relation indexRelation = info->index;
716 
718  CHECK_REL_PROCEDURE(amvacuumcleanup);
719 
720  return indexRelation->rd_indam->amvacuumcleanup(info, stats);
721 }
722 
723 /* ----------------
724  * index_can_return
725  *
726  * Does the index access method support index-only scans for the given
727  * column?
728  * ----------------
729  */
730 bool
731 index_can_return(Relation indexRelation, int attno)
732 {
734 
735  /* amcanreturn is optional; assume false if not provided by AM */
736  if (indexRelation->rd_indam->amcanreturn == NULL)
737  return false;
738 
739  return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
740 }
741 
742 /* ----------------
743  * index_getprocid
744  *
745  * Index access methods typically require support routines that are
746  * not directly the implementation of any WHERE-clause query operator
747  * and so cannot be kept in pg_amop. Instead, such routines are kept
748  * in pg_amproc. These registered procedure OIDs are assigned numbers
749  * according to a convention established by the access method.
750  * The general index code doesn't know anything about the routines
751  * involved; it just builds an ordered list of them for
752  * each attribute on which an index is defined.
753  *
754  * As of Postgres 8.3, support routines within an operator family
755  * are further subdivided by the "left type" and "right type" of the
756  * query operator(s) that they support. The "default" functions for a
757  * particular indexed attribute are those with both types equal to
758  * the index opclass' opcintype (note that this is subtly different
759  * from the indexed attribute's own type: it may be a binary-compatible
760  * type instead). Only the default functions are stored in relcache
761  * entries --- access methods can use the syscache to look up non-default
762  * functions.
763  *
764  * This routine returns the requested default procedure OID for a
765  * particular indexed attribute.
766  * ----------------
767  */
771  uint16 procnum)
772 {
773  RegProcedure *loc;
774  int nproc;
775  int procindex;
776 
777  nproc = irel->rd_indam->amsupport;
778 
779  Assert(procnum > 0 && procnum <= (uint16) nproc);
780 
781  procindex = (nproc * (attnum - 1)) + (procnum - 1);
782 
783  loc = irel->rd_support;
784 
785  Assert(loc != NULL);
786 
787  return loc[procindex];
788 }
789 
790 /* ----------------
791  * index_getprocinfo
792  *
793  * This routine allows index AMs to keep fmgr lookup info for
794  * support procs in the relcache. As above, only the "default"
795  * functions for any particular indexed attribute are cached.
796  *
797  * Note: the return value points into cached data that will be lost during
798  * any relcache rebuild! Therefore, either use the callinfo right away,
799  * or save it only after having acquired some type of lock on the index rel.
800  * ----------------
801  */
802 FmgrInfo *
805  uint16 procnum)
806 {
807  FmgrInfo *locinfo;
808  int nproc;
809  int optsproc;
810  int procindex;
811 
812  nproc = irel->rd_indam->amsupport;
813  optsproc = irel->rd_indam->amoptsprocnum;
814 
815  Assert(procnum > 0 && procnum <= (uint16) nproc);
816 
817  procindex = (nproc * (attnum - 1)) + (procnum - 1);
818 
819  locinfo = irel->rd_supportinfo;
820 
821  Assert(locinfo != NULL);
822 
823  locinfo += procindex;
824 
825  /* Initialize the lookup info if first time through */
826  if (locinfo->fn_oid == InvalidOid)
827  {
828  RegProcedure *loc = irel->rd_support;
829  RegProcedure procId;
830 
831  Assert(loc != NULL);
832 
833  procId = loc[procindex];
834 
835  /*
836  * Complain if function was not found during IndexSupportInitialize.
837  * This should not happen unless the system tables contain bogus
838  * entries for the index opclass. (If an AM wants to allow a support
839  * function to be optional, it can use index_getprocid.)
840  */
841  if (!RegProcedureIsValid(procId))
842  elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
843  procnum, attnum, RelationGetRelationName(irel));
844 
845  fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
846 
847  if (procnum != optsproc)
848  {
849  /* Initialize locinfo->fn_expr with opclass options Const */
850  bytea **attoptions = RelationGetIndexAttOptions(irel, false);
852 
853  set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
854 
855  MemoryContextSwitchTo(oldcxt);
856  }
857  }
858 
859  return locinfo;
860 }
861 
862 /* ----------------
863  * index_store_float8_orderby_distances
864  *
865  * Convert AM distance function's results (that can be inexact)
866  * to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
867  * for a possible recheck.
868  * ----------------
869  */
870 void
872  IndexOrderByDistance *distances,
873  bool recheckOrderBy)
874 {
875  int i;
876 
877  Assert(distances || !recheckOrderBy);
878 
879  scan->xs_recheckorderby = recheckOrderBy;
880 
881  for (i = 0; i < scan->numberOfOrderBys; i++)
882  {
883  if (orderByTypes[i] == FLOAT8OID)
884  {
885 #ifndef USE_FLOAT8_BYVAL
886  /* must free any old value to avoid memory leakage */
887  if (!scan->xs_orderbynulls[i])
889 #endif
890  if (distances && !distances[i].isnull)
891  {
892  scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
893  scan->xs_orderbynulls[i] = false;
894  }
895  else
896  {
897  scan->xs_orderbyvals[i] = (Datum) 0;
898  scan->xs_orderbynulls[i] = true;
899  }
900  }
901  else if (orderByTypes[i] == FLOAT4OID)
902  {
903  /* convert distance function's result to ORDER BY type */
904  if (distances && !distances[i].isnull)
905  {
906  scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
907  scan->xs_orderbynulls[i] = false;
908  }
909  else
910  {
911  scan->xs_orderbyvals[i] = (Datum) 0;
912  scan->xs_orderbynulls[i] = true;
913  }
914  }
915  else
916  {
917  /*
918  * If the ordering operator's return value is anything else, we
919  * don't know how to convert the float8 bound calculated by the
920  * distance function to that. The executor won't actually need
921  * the order by values we return here, if there are no lossy
922  * results, so only insist on converting if the *recheck flag is
923  * set.
924  */
925  if (scan->xs_recheckorderby)
926  elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
927  scan->xs_orderbynulls[i] = true;
928  }
929  }
930 }
931 
932 /* ----------------
933  * index_opclass_options
934  *
935  * Parse opclass-specific options for index column.
936  * ----------------
937  */
938 bytea *
940  bool validate)
941 {
942  int amoptsprocnum = indrel->rd_indam->amoptsprocnum;
943  Oid procid = InvalidOid;
944  FmgrInfo *procinfo;
945  local_relopts relopts;
946 
947  /* fetch options support procedure if specified */
948  if (amoptsprocnum != 0)
949  procid = index_getprocid(indrel, attnum, amoptsprocnum);
950 
951  if (!OidIsValid(procid))
952  {
953  Oid opclass;
954  Datum indclassDatum;
955  oidvector *indclass;
956  bool isnull;
957 
958  if (!DatumGetPointer(attoptions))
959  return NULL; /* ok, no options, no procedure */
960 
961  /*
962  * Report an error if the opclass's options-parsing procedure does not
963  * exist but the opclass options are specified.
964  */
965  indclassDatum = SysCacheGetAttr(INDEXRELID, indrel->rd_indextuple,
966  Anum_pg_index_indclass, &isnull);
967  Assert(!isnull);
968  indclass = (oidvector *) DatumGetPointer(indclassDatum);
969  opclass = indclass->values[attnum - 1];
970 
971  ereport(ERROR,
972  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
973  errmsg("operator class %s has no options",
974  generate_opclass_name(opclass))));
975  }
976 
977  init_local_reloptions(&relopts, 0);
978 
979  procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
980 
981  (void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
982 
983  return build_local_reloptions(&relopts, attoptions, validate);
984 }
static Datum Float4GetDatum(float4 X)
Definition: postgres.h:681
#define ItemPointerIsValid(pointer)
Definition: itemptr.h:82
ambeginscan_function ambeginscan
Definition: amapi.h:271
IndexScanDesc index_beginscan_bitmap(Relation indexRelation, Snapshot snapshot, int nkeys)
Definition: indexam.c:234
Definition: c.h:648
struct IndexAmRoutine * rd_indam
Definition: rel.h:189
Definition: fmgr.h:56
ambulkdelete_function ambulkdelete
Definition: amapi.h:262
LockRelId lockRelId
Definition: rel.h:44
uint16 amsupport
Definition: amapi.h:216
void init_local_reloptions(local_relopts *opts, Size relopt_struct_size)
Definition: reloptions.c:710
Snapshot RestoreSnapshot(char *start_address)
Definition: snapmgr.c:2157
FmgrInfo * index_getprocinfo(Relation irel, AttrNumber attnum, uint16 procnum)
Definition: indexam.c:803
Snapshot RegisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:810
amgettuple_function amgettuple
Definition: amapi.h:273
struct FmgrInfo * rd_supportinfo
Definition: rel.h:193
int LOCKMODE
Definition: lockdefs.h:26
void UnlockRelationId(LockRelId *relid, LOCKMODE lockmode)
Definition: lmgr.c:184
#define RELATION_CHECKS
Definition: indexam.c:79
IndexScanDesc index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys, int norderbys, ParallelIndexScanDesc pscan)
Definition: indexam.c:484
#define PointerGetDatum(X)
Definition: postgres.h:556
void index_markpos(IndexScanDesc scan)
Definition: indexam.c:353
void PredicateLockRelation(Relation relation, Snapshot snapshot)
Definition: predicate.c:2569
void * build_local_reloptions(local_relopts *relopts, Datum options, bool validate)
Definition: reloptions.c:1924
regproc RegProcedure
Definition: c.h:573
amparallelrescan_function amparallelrescan
Definition: amapi.h:282
static struct @144 value
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:297
static IndexFetchTableData * table_index_fetch_begin(Relation rel)
Definition: tableam.h:1074
int errcode(int sqlerrcode)
Definition: elog.c:704
Datum * xs_orderbyvals
Definition: relscan.h:158
TransactionId RecentXmin
Definition: snapmgr.c:113
Relation index
Definition: genam.h:46
bool xs_recheckorderby
Definition: relscan.h:160
bool ampredlocks
Definition: amapi.h:240
struct SnapshotData * xs_snapshot
Definition: relscan.h:116
void set_fn_opclass_options(FmgrInfo *flinfo, bytea *options)
Definition: fmgr.c:1963
char ps_snapshot_data[FLEXIBLE_ARRAY_MEMBER]
Definition: relscan.h:172
aminsert_function aminsert
Definition: amapi.h:261
Form_pg_class rd_rel
Definition: rel.h:110
unsigned int Oid
Definition: postgres_ext.h:31
#define OidIsValid(objectId)
Definition: c.h:698
#define CHECK_SCAN_PROCEDURE(pname)
Definition: indexam.c:100
Datum Float8GetDatum(float8 X)
Definition: fmgr.c:1709
Relation indexRelation
Definition: relscan.h:115
#define CHECK_REL_PROCEDURE(pname)
Definition: indexam.c:93
struct HeapTupleData * rd_indextuple
Definition: rel.h:177
Size index_parallelscan_estimate(Relation indexRelation, Snapshot snapshot)
Definition: indexam.c:402
void index_parallelrescan(IndexScanDesc scan)
Definition: indexam.c:466
Relation heapRelation
Definition: relscan.h:114
IndexUniqueCheck
Definition: genam.h:112
void index_restrpos(IndexScanDesc scan)
Definition: indexam.c:377
bool index_can_return(Relation indexRelation, int attno)
Definition: indexam.c:731
bool * xs_orderbynulls
Definition: relscan.h:159
ItemPointer index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
Definition: indexam.c:517
unsigned short uint16
Definition: c.h:428
void pfree(void *pointer)
Definition: mcxt.c:1057
void RelationDecrementReferenceCount(Relation rel)
Definition: relcache.c:2103
amgetbitmap_function amgetbitmap
Definition: amapi.h:274
#define ERROR
Definition: elog.h:45
Definition: rel.h:36
void SerializeSnapshot(Snapshot snapshot, char *start_address)
Definition: snapmgr.c:2098
Relation relation_open(Oid relationId, LOCKMODE lockmode)
Definition: relation.c:48
static void callback(struct sockaddr *addr, struct sockaddr *mask, void *unused)
Definition: test_ifaddrs.c:48
#define pgstat_count_heap_fetch(rel)
Definition: pgstat.h:1538
ItemPointerData xs_heaptid
Definition: relscan.h:144
#define NoLock
Definition: lockdefs.h:34
LockInfoData rd_lockInfo
Definition: rel.h:113
amvacuumcleanup_function amvacuumcleanup
Definition: amapi.h:263
amendscan_function amendscan
Definition: amapi.h:275
bool xactStartedInRecovery
Definition: relscan.h:127
Oid values[FLEXIBLE_ARRAY_MEMBER]
Definition: c.h:656
#define RegProcedureIsValid(p)
Definition: c.h:700
ScanDirection
Definition: sdir.h:22
#define RelationGetRelationName(relation)
Definition: rel.h:491
void IndexScanEnd(IndexScanDesc scan)
Definition: genam.c:145
void RelationClose(Relation relation)
Definition: relcache.c:2123
void fmgr_info_cxt(Oid functionId, FmgrInfo *finfo, MemoryContext mcxt)
Definition: fmgr.c:136
#define OffsetToPointer(base, offset)
Definition: c.h:695
void index_endscan(IndexScanDesc scan)
Definition: indexam.c:323
amrescan_function amrescan
Definition: amapi.h:272
RegProcedure * rd_support
Definition: rel.h:192
int64 index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
Definition: indexam.c:661
bytea * index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions, bool validate)
Definition: indexam.c:939
void UnregisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:852
float float4
Definition: c.h:552
char * generate_opclass_name(Oid opclass)
Definition: ruleutils.c:10803
Size EstimateSnapshotSpace(Snapshot snap)
Definition: snapmgr.c:2074
#define MAX_LOCKMODES
Definition: lock.h:84
struct ParallelIndexScanDescData * parallel_scan
Definition: relscan.h:163
void RelationIncrementReferenceCount(Relation rel)
Definition: relcache.c:2090
void index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes, IndexOrderByDistance *distances, bool recheckOrderBy)
Definition: indexam.c:871
IndexBulkDeleteResult * index_bulk_delete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats, IndexBulkDeleteCallback callback, void *callback_state)
Definition: indexam.c:691
uintptr_t Datum
Definition: postgres.h:367
Size add_size(Size s1, Size s2)
Definition: shmem.c:502
Datum SysCacheGetAttr(int cacheId, HeapTuple tup, AttrNumber attributeNumber, bool *isNull)
Definition: syscache.c:1388
static bool table_index_fetch_tuple(struct IndexFetchTableData *scan, ItemPointer tid, Snapshot snapshot, TupleTableSlot *slot, bool *call_again, bool *all_dead)
Definition: tableam.h:1123
void CheckForSerializableConflictIn(Relation relation, ItemPointer tid, BlockNumber blkno)
Definition: predicate.c:4446
#define IsMVCCSnapshot(snapshot)
Definition: snapmgr.h:97
#define InvalidOid
Definition: postgres_ext.h:36
int16 attnum
Definition: pg_attribute.h:79
Oid fn_oid
Definition: fmgr.h:59
#define ereport(elevel,...)
Definition: elog.h:155
static void table_index_fetch_reset(struct IndexFetchTableData *scan)
Definition: tableam.h:1084
static IndexScanDesc index_beginscan_internal(Relation indexRelation, int nkeys, int norderbys, Snapshot snapshot, ParallelIndexScanDesc pscan, bool temp_snap)
Definition: indexam.c:255
#define Assert(condition)
Definition: c.h:792
IndexFetchTableData * xs_heapfetch
Definition: relscan.h:147
size_t Size
Definition: c.h:528
#define SCAN_CHECKS
Definition: indexam.c:86
#define InvalidBlockNumber
Definition: block.h:33
bool index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
Definition: indexam.c:616
#define MAXALIGN(LEN)
Definition: c.h:745
bool xs_heap_continue
Definition: relscan.h:145
ammarkpos_function ammarkpos
Definition: amapi.h:276
#define pgstat_count_index_tuples(rel, n)
Definition: pgstat.h:1548
IndexBulkDeleteResult * index_vacuum_cleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
Definition: indexam.c:712
amestimateparallelscan_function amestimateparallelscan
Definition: amapi.h:280
bool ItemPointerEquals(ItemPointer pointer1, ItemPointer pointer2)
Definition: itemptr.c:29
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:158
#define DatumGetPointer(X)
Definition: postgres.h:549
static Datum values[MAXATTR]
Definition: bootstrap.c:165
int errmsg(const char *fmt,...)
Definition: elog.c:915
uint16 amoptsprocnum
Definition: amapi.h:218
void index_parallelscan_initialize(Relation heapRelation, Relation indexRelation, Snapshot snapshot, ParallelIndexScanDesc target)
Definition: indexam.c:435
#define elog(elevel,...)
Definition: elog.h:228
MemoryContext rd_indexcxt
Definition: rel.h:187
int i
bool kill_prior_tuple
Definition: relscan.h:125
#define FunctionCall1(flinfo, arg1)
Definition: fmgr.h:644
bool index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
Definition: indexam.c:575
Definition: c.h:609
int numberOfOrderBys
Definition: relscan.h:118
bool index_insert(Relation indexRelation, Datum *values, bool *isnull, ItemPointer heap_t_ctid, Relation heapRelation, IndexUniqueCheck checkUnique, bool indexUnchanged, IndexInfo *indexInfo)
Definition: indexam.c:176
bytea ** RelationGetIndexAttOptions(Relation relation, bool copy)
Definition: relcache.c:5448
#define TransactionIdIsValid(xid)
Definition: transam.h:41
static void table_index_fetch_end(struct IndexFetchTableData *scan)
Definition: tableam.h:1093
amcanreturn_function amcanreturn
Definition: amapi.h:264
int16 AttrNumber
Definition: attnum.h:21
#define RelationGetRelid(relation)
Definition: rel.h:457
Relation index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:132
#define offsetof(type, field)
Definition: c.h:715
bool(* IndexBulkDeleteCallback)(ItemPointer itemptr, void *state)
Definition: genam.h:84
aminitparallelscan_function aminitparallelscan
Definition: amapi.h:281
IndexScanDesc index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, int norderbys)
Definition: indexam.c:205
amrestrpos_function amrestrpos
Definition: amapi.h:277
RegProcedure index_getprocid(Relation irel, AttrNumber attnum, uint16 procnum)
Definition: indexam.c:769