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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) 1996-2019, 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/relscan.h"
49 #include "access/tableam.h"
50 #include "access/transam.h"
51 #include "access/xlog.h"
52 #include "catalog/index.h"
53 #include "catalog/pg_type.h"
54 #include "pgstat.h"
55 #include "storage/bufmgr.h"
56 #include "storage/lmgr.h"
57 #include "storage/predicate.h"
58 #include "utils/snapmgr.h"
59 
60 
61 /* ----------------------------------------------------------------
62  * macros used in index_ routines
63  *
64  * Note: the ReindexIsProcessingIndex() check in RELATION_CHECKS is there
65  * to check that we don't try to scan or do retail insertions into an index
66  * that is currently being rebuilt or pending rebuild. This helps to catch
67  * things that don't work when reindexing system catalogs. The assertion
68  * doesn't prevent the actual rebuild because we don't use RELATION_CHECKS
69  * when calling the index AM's ambuild routine, and there is no reason for
70  * ambuild to call its subsidiary routines through this file.
71  * ----------------------------------------------------------------
72  */
73 #define RELATION_CHECKS \
74 ( \
75  AssertMacro(RelationIsValid(indexRelation)), \
76  AssertMacro(PointerIsValid(indexRelation->rd_indam)), \
77  AssertMacro(!ReindexIsProcessingIndex(RelationGetRelid(indexRelation))) \
78 )
79 
80 #define SCAN_CHECKS \
81 ( \
82  AssertMacro(IndexScanIsValid(scan)), \
83  AssertMacro(RelationIsValid(scan->indexRelation)), \
84  AssertMacro(PointerIsValid(scan->indexRelation->rd_indam)) \
85 )
86 
87 #define CHECK_REL_PROCEDURE(pname) \
88 do { \
89  if (indexRelation->rd_indam->pname == NULL) \
90  elog(ERROR, "function %s is not defined for index %s", \
91  CppAsString(pname), RelationGetRelationName(indexRelation)); \
92 } while(0)
93 
94 #define CHECK_SCAN_PROCEDURE(pname) \
95 do { \
96  if (scan->indexRelation->rd_indam->pname == NULL) \
97  elog(ERROR, "function %s is not defined for index %s", \
98  CppAsString(pname), RelationGetRelationName(scan->indexRelation)); \
99 } while(0)
100 
101 static IndexScanDesc index_beginscan_internal(Relation indexRelation,
102  int nkeys, int norderbys, Snapshot snapshot,
103  ParallelIndexScanDesc pscan, bool temp_snap);
104 
105 
106 /* ----------------------------------------------------------------
107  * index_ interface functions
108  * ----------------------------------------------------------------
109  */
110 
111 /* ----------------
112  * index_open - open an index relation by relation OID
113  *
114  * If lockmode is not "NoLock", the specified kind of lock is
115  * obtained on the index. (Generally, NoLock should only be
116  * used if the caller knows it has some appropriate lock on the
117  * index already.)
118  *
119  * An error is raised if the index does not exist.
120  *
121  * This is a convenience routine adapted for indexscan use.
122  * Some callers may prefer to use relation_open directly.
123  * ----------------
124  */
125 Relation
126 index_open(Oid relationId, LOCKMODE lockmode)
127 {
128  Relation r;
129 
130  r = relation_open(relationId, lockmode);
131 
132  if (r->rd_rel->relkind != RELKIND_INDEX &&
133  r->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
134  ereport(ERROR,
135  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
136  errmsg("\"%s\" is not an index",
138 
139  return r;
140 }
141 
142 /* ----------------
143  * index_close - close an index relation
144  *
145  * If lockmode is not "NoLock", we then release the specified lock.
146  *
147  * Note that it is often sensible to hold a lock beyond index_close;
148  * in that case, the lock is released automatically at xact end.
149  * ----------------
150  */
151 void
152 index_close(Relation relation, LOCKMODE lockmode)
153 {
154  LockRelId relid = relation->rd_lockInfo.lockRelId;
155 
156  Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
157 
158  /* The relcache does the real work... */
159  RelationClose(relation);
160 
161  if (lockmode != NoLock)
162  UnlockRelationId(&relid, lockmode);
163 }
164 
165 /* ----------------
166  * index_insert - insert an index tuple into a relation
167  * ----------------
168  */
169 bool
170 index_insert(Relation indexRelation,
171  Datum *values,
172  bool *isnull,
173  ItemPointer heap_t_ctid,
174  Relation heapRelation,
175  IndexUniqueCheck checkUnique,
176  IndexInfo *indexInfo)
177 {
179  CHECK_REL_PROCEDURE(aminsert);
180 
181  if (!(indexRelation->rd_indam->ampredlocks))
182  CheckForSerializableConflictIn(indexRelation,
183  (HeapTuple) NULL,
184  InvalidBuffer);
185 
186  return indexRelation->rd_indam->aminsert(indexRelation, values, isnull,
187  heap_t_ctid, heapRelation,
188  checkUnique, indexInfo);
189 }
190 
191 /*
192  * index_beginscan - start a scan of an index with amgettuple
193  *
194  * Caller must be holding suitable locks on the heap and the index.
195  */
198  Relation indexRelation,
199  Snapshot snapshot,
200  int nkeys, int norderbys)
201 {
202  IndexScanDesc scan;
203 
204  scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
205 
206  /*
207  * Save additional parameters into the scandesc. Everything else was set
208  * up by RelationGetIndexScan.
209  */
210  scan->heapRelation = heapRelation;
211  scan->xs_snapshot = snapshot;
212 
213  /* prepare to fetch index matches from table */
214  scan->xs_heapfetch = table_index_fetch_begin(heapRelation);
215 
216  return scan;
217 }
218 
219 /*
220  * index_beginscan_bitmap - start a scan of an index with amgetbitmap
221  *
222  * As above, caller had better be holding some lock on the parent heap
223  * relation, even though it's not explicitly mentioned here.
224  */
227  Snapshot snapshot,
228  int nkeys)
229 {
230  IndexScanDesc scan;
231 
232  scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
233 
234  /*
235  * Save additional parameters into the scandesc. Everything else was set
236  * up by RelationGetIndexScan.
237  */
238  scan->xs_snapshot = snapshot;
239 
240  return scan;
241 }
242 
243 /*
244  * index_beginscan_internal --- common code for index_beginscan variants
245  */
246 static IndexScanDesc
248  int nkeys, int norderbys, Snapshot snapshot,
249  ParallelIndexScanDesc pscan, bool temp_snap)
250 {
251  IndexScanDesc scan;
252 
254  CHECK_REL_PROCEDURE(ambeginscan);
255 
256  if (!(indexRelation->rd_indam->ampredlocks))
257  PredicateLockRelation(indexRelation, snapshot);
258 
259  /*
260  * We hold a reference count to the relcache entry throughout the scan.
261  */
262  RelationIncrementReferenceCount(indexRelation);
263 
264  /*
265  * Tell the AM to open a scan.
266  */
267  scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
268  norderbys);
269  /* Initialize information for parallel scan. */
270  scan->parallel_scan = pscan;
271  scan->xs_temp_snap = temp_snap;
272 
273  return scan;
274 }
275 
276 /* ----------------
277  * index_rescan - (re)start a scan of an index
278  *
279  * During a restart, the caller may specify a new set of scankeys and/or
280  * orderbykeys; but the number of keys cannot differ from what index_beginscan
281  * was told. (Later we might relax that to "must not exceed", but currently
282  * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
283  * To restart the scan without changing keys, pass NULL for the key arrays.
284  * (Of course, keys *must* be passed on the first call, unless
285  * scan->numberOfKeys is zero.)
286  * ----------------
287  */
288 void
290  ScanKey keys, int nkeys,
291  ScanKey orderbys, int norderbys)
292 {
293  SCAN_CHECKS;
294  CHECK_SCAN_PROCEDURE(amrescan);
295 
296  Assert(nkeys == scan->numberOfKeys);
297  Assert(norderbys == scan->numberOfOrderBys);
298 
299  /* Release resources (like buffer pins) from table accesses */
300  if (scan->xs_heapfetch)
302 
303  scan->kill_prior_tuple = false; /* for safety */
304  scan->xs_heap_continue = false;
305 
306  scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
307  orderbys, norderbys);
308 }
309 
310 /* ----------------
311  * index_endscan - end a scan
312  * ----------------
313  */
314 void
316 {
317  SCAN_CHECKS;
318  CHECK_SCAN_PROCEDURE(amendscan);
319 
320  /* Release resources (like buffer pins) from table accesses */
321  if (scan->xs_heapfetch)
322  {
324  scan->xs_heapfetch = NULL;
325  }
326 
327  /* End the AM's scan */
328  scan->indexRelation->rd_indam->amendscan(scan);
329 
330  /* Release index refcount acquired by index_beginscan */
332 
333  if (scan->xs_temp_snap)
335 
336  /* Release the scan data structure itself */
337  IndexScanEnd(scan);
338 }
339 
340 /* ----------------
341  * index_markpos - mark a scan position
342  * ----------------
343  */
344 void
346 {
347  SCAN_CHECKS;
348  CHECK_SCAN_PROCEDURE(ammarkpos);
349 
350  scan->indexRelation->rd_indam->ammarkpos(scan);
351 }
352 
353 /* ----------------
354  * index_restrpos - restore a scan position
355  *
356  * NOTE: this only restores the internal scan state of the index AM. See
357  * comments for ExecRestrPos().
358  *
359  * NOTE: For heap, in the presence of HOT chains, mark/restore only works
360  * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
361  * most one returnable tuple in each HOT chain, and so restoring the prior
362  * state at the granularity of the index AM is sufficient. Since the only
363  * current user of mark/restore functionality is nodeMergejoin.c, this
364  * effectively means that merge-join plans only work for MVCC snapshots. This
365  * could be fixed if necessary, but for now it seems unimportant.
366  * ----------------
367  */
368 void
370 {
372 
373  SCAN_CHECKS;
374  CHECK_SCAN_PROCEDURE(amrestrpos);
375 
376  /* release resources (like buffer pins) from table accesses */
377  if (scan->xs_heapfetch)
379 
380  scan->kill_prior_tuple = false; /* for safety */
381  scan->xs_heap_continue = false;
382 
383  scan->indexRelation->rd_indam->amrestrpos(scan);
384 }
385 
386 /*
387  * index_parallelscan_estimate - estimate shared memory for parallel scan
388  *
389  * Currently, we don't pass any information to the AM-specific estimator,
390  * so it can probably only return a constant. In the future, we might need
391  * to pass more information.
392  */
393 Size
395 {
396  Size nbytes;
397 
399 
400  nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
401  nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
402  nbytes = MAXALIGN(nbytes);
403 
404  /*
405  * If amestimateparallelscan is not provided, assume there is no
406  * AM-specific data needed. (It's hard to believe that could work, but
407  * it's easy enough to cater to it here.)
408  */
409  if (indexRelation->rd_indam->amestimateparallelscan != NULL)
410  nbytes = add_size(nbytes,
411  indexRelation->rd_indam->amestimateparallelscan());
412 
413  return nbytes;
414 }
415 
416 /*
417  * index_parallelscan_initialize - initialize parallel scan
418  *
419  * We initialize both the ParallelIndexScanDesc proper and the AM-specific
420  * information which follows it.
421  *
422  * This function calls access method specific initialization routine to
423  * initialize am specific information. Call this just once in the leader
424  * process; then, individual workers attach via index_beginscan_parallel.
425  */
426 void
427 index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
428  Snapshot snapshot, ParallelIndexScanDesc target)
429 {
430  Size offset;
431 
433 
434  offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
435  EstimateSnapshotSpace(snapshot));
436  offset = MAXALIGN(offset);
437 
438  target->ps_relid = RelationGetRelid(heapRelation);
439  target->ps_indexid = RelationGetRelid(indexRelation);
440  target->ps_offset = offset;
441  SerializeSnapshot(snapshot, target->ps_snapshot_data);
442 
443  /* aminitparallelscan is optional; assume no-op if not provided by AM */
444  if (indexRelation->rd_indam->aminitparallelscan != NULL)
445  {
446  void *amtarget;
447 
448  amtarget = OffsetToPointer(target, offset);
449  indexRelation->rd_indam->aminitparallelscan(amtarget);
450  }
451 }
452 
453 /* ----------------
454  * index_parallelrescan - (re)start a parallel scan of an index
455  * ----------------
456  */
457 void
459 {
460  SCAN_CHECKS;
461 
462  if (scan->xs_heapfetch)
464 
465  /* amparallelrescan is optional; assume no-op if not provided by AM */
466  if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
468 }
469 
470 /*
471  * index_beginscan_parallel - join parallel index scan
472  *
473  * Caller must be holding suitable locks on the heap and the index.
474  */
476 index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys,
477  int norderbys, ParallelIndexScanDesc pscan)
478 {
479  Snapshot snapshot;
480  IndexScanDesc scan;
481 
482  Assert(RelationGetRelid(heaprel) == pscan->ps_relid);
483  snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
484  RegisterSnapshot(snapshot);
485  scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
486  pscan, true);
487 
488  /*
489  * Save additional parameters into the scandesc. Everything else was set
490  * up by index_beginscan_internal.
491  */
492  scan->heapRelation = heaprel;
493  scan->xs_snapshot = snapshot;
494 
495  /* prepare to fetch index matches from table */
496  scan->xs_heapfetch = table_index_fetch_begin(heaprel);
497 
498  return scan;
499 }
500 
501 /* ----------------
502  * index_getnext_tid - get the next TID from a scan
503  *
504  * The result is the next TID satisfying the scan keys,
505  * or NULL if no more matching tuples exist.
506  * ----------------
507  */
510 {
511  bool found;
512 
513  SCAN_CHECKS;
514  CHECK_SCAN_PROCEDURE(amgettuple);
515 
517 
518  /*
519  * The AM's amgettuple proc finds the next index entry matching the scan
520  * keys, and puts the TID into scan->xs_heaptid. It should also set
521  * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
522  * pay no attention to those fields here.
523  */
524  found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
525 
526  /* Reset kill flag immediately for safety */
527  scan->kill_prior_tuple = false;
528  scan->xs_heap_continue = false;
529 
530  /* If we're out of index entries, we're done */
531  if (!found)
532  {
533  /* release resources (like buffer pins) from table accesses */
534  if (scan->xs_heapfetch)
536 
537  return NULL;
538  }
540 
542 
543  /* Return the TID of the tuple we found. */
544  return &scan->xs_heaptid;
545 }
546 
547 /* ----------------
548  * index_fetch_heap - get the scan's next heap tuple
549  *
550  * The result is a visible heap tuple associated with the index TID most
551  * recently fetched by index_getnext_tid, or NULL if no more matching tuples
552  * exist. (There can be more than one matching tuple because of HOT chains,
553  * although when using an MVCC snapshot it should be impossible for more than
554  * one such tuple to exist.)
555  *
556  * On success, the buffer containing the heap tup is pinned (the pin will be
557  * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
558  * call).
559  *
560  * Note: caller must check scan->xs_recheck, and perform rechecking of the
561  * scan keys if required. We do not do that here because we don't have
562  * enough information to do it efficiently in the general case.
563  * ----------------
564  */
565 bool
567 {
568  bool all_dead = false;
569  bool found;
570 
571  found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
572  scan->xs_snapshot, slot,
573  &scan->xs_heap_continue, &all_dead);
574 
575  if (found)
577 
578  /*
579  * If we scanned a whole HOT chain and found only dead tuples, tell index
580  * AM to kill its entry for that TID (this will take effect in the next
581  * amgettuple call, in index_getnext_tid). We do not do this when in
582  * recovery because it may violate MVCC to do so. See comments in
583  * RelationGetIndexScan().
584  */
585  if (!scan->xactStartedInRecovery)
586  scan->kill_prior_tuple = all_dead;
587 
588  return found;
589 }
590 
591 /* ----------------
592  * index_getnext_slot - get the next tuple from a scan
593  *
594  * The result is true if a tuple satisfying the scan keys and the snapshot was
595  * found, false otherwise. The tuple is stored in the specified slot.
596  *
597  * On success, resources (like buffer pins) are likely to be held, and will be
598  * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
599  * call).
600  *
601  * Note: caller must check scan->xs_recheck, and perform rechecking of the
602  * scan keys if required. We do not do that here because we don't have
603  * enough information to do it efficiently in the general case.
604  * ----------------
605  */
606 bool
608 {
609  for (;;)
610  {
611  if (!scan->xs_heap_continue)
612  {
613  ItemPointer tid;
614 
615  /* Time to fetch the next TID from the index */
616  tid = index_getnext_tid(scan, direction);
617 
618  /* If we're out of index entries, we're done */
619  if (tid == NULL)
620  break;
621 
622  Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
623  }
624 
625  /*
626  * Fetch the next (or only) visible heap tuple for this index entry.
627  * If we don't find anything, loop around and grab the next TID from
628  * the index.
629  */
631  if (index_fetch_heap(scan, slot))
632  return true;
633  }
634 
635  return false;
636 }
637 
638 /* ----------------
639  * index_getbitmap - get all tuples at once from an index scan
640  *
641  * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
642  * Since there's no interlock between the index scan and the eventual heap
643  * access, this is only safe to use with MVCC-based snapshots: the heap
644  * item slot could have been replaced by a newer tuple by the time we get
645  * to it.
646  *
647  * Returns the number of matching tuples found. (Note: this might be only
648  * approximate, so it should only be used for statistical purposes.)
649  * ----------------
650  */
651 int64
653 {
654  int64 ntids;
655 
656  SCAN_CHECKS;
657  CHECK_SCAN_PROCEDURE(amgetbitmap);
658 
659  /* just make sure this is false... */
660  scan->kill_prior_tuple = false;
661 
662  /*
663  * have the am's getbitmap proc do all the work.
664  */
665  ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
666 
668 
669  return ntids;
670 }
671 
672 /* ----------------
673  * index_bulk_delete - do mass deletion of index entries
674  *
675  * callback routine tells whether a given main-heap tuple is
676  * to be deleted
677  *
678  * return value is an optional palloc'd struct of statistics
679  * ----------------
680  */
683  IndexBulkDeleteResult *stats,
685  void *callback_state)
686 {
687  Relation indexRelation = info->index;
688 
690  CHECK_REL_PROCEDURE(ambulkdelete);
691 
692  return indexRelation->rd_indam->ambulkdelete(info, stats,
693  callback, callback_state);
694 }
695 
696 /* ----------------
697  * index_vacuum_cleanup - do post-deletion cleanup of an index
698  *
699  * return value is an optional palloc'd struct of statistics
700  * ----------------
701  */
704  IndexBulkDeleteResult *stats)
705 {
706  Relation indexRelation = info->index;
707 
709  CHECK_REL_PROCEDURE(amvacuumcleanup);
710 
711  return indexRelation->rd_indam->amvacuumcleanup(info, stats);
712 }
713 
714 /* ----------------
715  * index_can_return
716  *
717  * Does the index access method support index-only scans for the given
718  * column?
719  * ----------------
720  */
721 bool
722 index_can_return(Relation indexRelation, int attno)
723 {
725 
726  /* amcanreturn is optional; assume false if not provided by AM */
727  if (indexRelation->rd_indam->amcanreturn == NULL)
728  return false;
729 
730  return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
731 }
732 
733 /* ----------------
734  * index_getprocid
735  *
736  * Index access methods typically require support routines that are
737  * not directly the implementation of any WHERE-clause query operator
738  * and so cannot be kept in pg_amop. Instead, such routines are kept
739  * in pg_amproc. These registered procedure OIDs are assigned numbers
740  * according to a convention established by the access method.
741  * The general index code doesn't know anything about the routines
742  * involved; it just builds an ordered list of them for
743  * each attribute on which an index is defined.
744  *
745  * As of Postgres 8.3, support routines within an operator family
746  * are further subdivided by the "left type" and "right type" of the
747  * query operator(s) that they support. The "default" functions for a
748  * particular indexed attribute are those with both types equal to
749  * the index opclass' opcintype (note that this is subtly different
750  * from the indexed attribute's own type: it may be a binary-compatible
751  * type instead). Only the default functions are stored in relcache
752  * entries --- access methods can use the syscache to look up non-default
753  * functions.
754  *
755  * This routine returns the requested default procedure OID for a
756  * particular indexed attribute.
757  * ----------------
758  */
762  uint16 procnum)
763 {
764  RegProcedure *loc;
765  int nproc;
766  int procindex;
767 
768  nproc = irel->rd_indam->amsupport;
769 
770  Assert(procnum > 0 && procnum <= (uint16) nproc);
771 
772  procindex = (nproc * (attnum - 1)) + (procnum - 1);
773 
774  loc = irel->rd_support;
775 
776  Assert(loc != NULL);
777 
778  return loc[procindex];
779 }
780 
781 /* ----------------
782  * index_getprocinfo
783  *
784  * This routine allows index AMs to keep fmgr lookup info for
785  * support procs in the relcache. As above, only the "default"
786  * functions for any particular indexed attribute are cached.
787  *
788  * Note: the return value points into cached data that will be lost during
789  * any relcache rebuild! Therefore, either use the callinfo right away,
790  * or save it only after having acquired some type of lock on the index rel.
791  * ----------------
792  */
793 FmgrInfo *
796  uint16 procnum)
797 {
798  FmgrInfo *locinfo;
799  int nproc;
800  int procindex;
801 
802  nproc = irel->rd_indam->amsupport;
803 
804  Assert(procnum > 0 && procnum <= (uint16) nproc);
805 
806  procindex = (nproc * (attnum - 1)) + (procnum - 1);
807 
808  locinfo = irel->rd_supportinfo;
809 
810  Assert(locinfo != NULL);
811 
812  locinfo += procindex;
813 
814  /* Initialize the lookup info if first time through */
815  if (locinfo->fn_oid == InvalidOid)
816  {
817  RegProcedure *loc = irel->rd_support;
818  RegProcedure procId;
819 
820  Assert(loc != NULL);
821 
822  procId = loc[procindex];
823 
824  /*
825  * Complain if function was not found during IndexSupportInitialize.
826  * This should not happen unless the system tables contain bogus
827  * entries for the index opclass. (If an AM wants to allow a support
828  * function to be optional, it can use index_getprocid.)
829  */
830  if (!RegProcedureIsValid(procId))
831  elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
832  procnum, attnum, RelationGetRelationName(irel));
833 
834  fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
835  }
836 
837  return locinfo;
838 }
839 
840 /* ----------------
841  * index_store_float8_orderby_distances
842  *
843  * Convert AM distance function's results (that can be inexact)
844  * to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
845  * for a possible recheck.
846  * ----------------
847  */
848 void
850  IndexOrderByDistance *distances,
851  bool recheckOrderBy)
852 {
853  int i;
854 
855  Assert(distances || !recheckOrderBy);
856 
857  scan->xs_recheckorderby = recheckOrderBy;
858 
859  for (i = 0; i < scan->numberOfOrderBys; i++)
860  {
861  if (orderByTypes[i] == FLOAT8OID)
862  {
863 #ifndef USE_FLOAT8_BYVAL
864  /* must free any old value to avoid memory leakage */
865  if (!scan->xs_orderbynulls[i])
867 #endif
868  if (distances && !distances[i].isnull)
869  {
870  scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
871  scan->xs_orderbynulls[i] = false;
872  }
873  else
874  {
875  scan->xs_orderbyvals[i] = (Datum) 0;
876  scan->xs_orderbynulls[i] = true;
877  }
878  }
879  else if (orderByTypes[i] == FLOAT4OID)
880  {
881  /* convert distance function's result to ORDER BY type */
882 #ifndef USE_FLOAT4_BYVAL
883  /* must free any old value to avoid memory leakage */
884  if (!scan->xs_orderbynulls[i])
886 #endif
887  if (distances && !distances[i].isnull)
888  {
889  scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
890  scan->xs_orderbynulls[i] = false;
891  }
892  else
893  {
894  scan->xs_orderbyvals[i] = (Datum) 0;
895  scan->xs_orderbynulls[i] = true;
896  }
897  }
898  else
899  {
900  /*
901  * If the ordering operator's return value is anything else, we
902  * don't know how to convert the float8 bound calculated by the
903  * distance function to that. The executor won't actually need
904  * the order by values we return here, if there are no lossy
905  * results, so only insist on converting if the *recheck flag is
906  * set.
907  */
908  if (scan->xs_recheckorderby)
909  elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
910  scan->xs_orderbynulls[i] = true;
911  }
912  }
913 }
#define ItemPointerIsValid(pointer)
Definition: itemptr.h:82
ambeginscan_function ambeginscan
Definition: amapi.h:221
IndexScanDesc index_beginscan_bitmap(Relation indexRelation, Snapshot snapshot, int nkeys)
Definition: indexam.c:226
struct IndexAmRoutine * rd_indam
Definition: rel.h:157
Definition: fmgr.h:56
ambulkdelete_function ambulkdelete
Definition: amapi.h:213
LockRelId lockRelId
Definition: rel.h:43
uint16 amsupport
Definition: amapi.h:173
Snapshot RestoreSnapshot(char *start_address)
Definition: snapmgr.c:2161
FmgrInfo * index_getprocinfo(Relation irel, AttrNumber attnum, uint16 procnum)
Definition: indexam.c:794
Snapshot RegisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:865
amgettuple_function amgettuple
Definition: amapi.h:223
struct FmgrInfo * rd_supportinfo
Definition: rel.h:161
int LOCKMODE
Definition: lockdefs.h:26
void UnlockRelationId(LockRelId *relid, LOCKMODE lockmode)
Definition: lmgr.c:184
#define RELATION_CHECKS
Definition: indexam.c:73
IndexScanDesc index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys, int norderbys, ParallelIndexScanDesc pscan)
Definition: indexam.c:476
void index_markpos(IndexScanDesc scan)
Definition: indexam.c:345
void PredicateLockRelation(Relation relation, Snapshot snapshot)
Definition: predicate.c:2503
regproc RegProcedure
Definition: c.h:506
amparallelrescan_function amparallelrescan
Definition: amapi.h:232
#define InvalidBuffer
Definition: buf.h:25
static struct @145 value
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:289
static IndexFetchTableData * table_index_fetch_begin(Relation rel)
Definition: tableam.h:934
int errcode(int sqlerrcode)
Definition: elog.c:608
Datum * xs_orderbyvals
Definition: relscan.h:146
Relation index
Definition: genam.h:46
bool xs_recheckorderby
Definition: relscan.h:148
bool ampredlocks
Definition: amapi.h:195
struct SnapshotData * xs_snapshot
Definition: relscan.h:104
char ps_snapshot_data[FLEXIBLE_ARRAY_MEMBER]
Definition: relscan.h:160
aminsert_function aminsert
Definition: amapi.h:212
Form_pg_class rd_rel
Definition: rel.h:83
unsigned int Oid
Definition: postgres_ext.h:31
void CheckForSerializableConflictIn(Relation relation, HeapTuple tuple, Buffer buffer)
Definition: predicate.c:4426
#define CHECK_SCAN_PROCEDURE(pname)
Definition: indexam.c:94
Datum Float8GetDatum(float8 X)
Definition: fmgr.c:1723
Relation indexRelation
Definition: relscan.h:103
#define CHECK_REL_PROCEDURE(pname)
Definition: indexam.c:87
Size index_parallelscan_estimate(Relation indexRelation, Snapshot snapshot)
Definition: indexam.c:394
void index_parallelrescan(IndexScanDesc scan)
Definition: indexam.c:458
Relation heapRelation
Definition: relscan.h:102
IndexUniqueCheck
Definition: genam.h:112
void index_restrpos(IndexScanDesc scan)
Definition: indexam.c:369
bool index_can_return(Relation indexRelation, int attno)
Definition: indexam.c:722
bool * xs_orderbynulls
Definition: relscan.h:147
ItemPointer index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
Definition: indexam.c:509
unsigned short uint16
Definition: c.h:358
void pfree(void *pointer)
Definition: mcxt.c:1056
void RelationDecrementReferenceCount(Relation rel)
Definition: relcache.c:2068
amgetbitmap_function amgetbitmap
Definition: amapi.h:224
#define ERROR
Definition: elog.h:43
Definition: rel.h:35
void SerializeSnapshot(Snapshot snapshot, char *start_address)
Definition: snapmgr.c:2102
Relation relation_open(Oid relationId, LOCKMODE lockmode)
Definition: relation.c:48
Datum Float4GetDatum(float4 X)
Definition: fmgr.c:1711
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:1368
ItemPointerData xs_heaptid
Definition: relscan.h:132
#define NoLock
Definition: lockdefs.h:34
LockInfoData rd_lockInfo
Definition: rel.h:86
amvacuumcleanup_function amvacuumcleanup
Definition: amapi.h:214
amendscan_function amendscan
Definition: amapi.h:225
bool xactStartedInRecovery
Definition: relscan.h:115
TransactionId RecentGlobalXmin
Definition: snapmgr.c:168
#define RegProcedureIsValid(p)
Definition: c.h:641
ScanDirection
Definition: sdir.h:22
#define RelationGetRelationName(relation)
Definition: rel.h:457
void IndexScanEnd(IndexScanDesc scan)
Definition: genam.c:144
void RelationClose(Relation relation)
Definition: relcache.c:2088
void fmgr_info_cxt(Oid functionId, FmgrInfo *finfo, MemoryContext mcxt)
Definition: fmgr.c:134
#define OffsetToPointer(base, offset)
Definition: c.h:636
void index_endscan(IndexScanDesc scan)
Definition: indexam.c:315
#define ereport(elevel, rest)
Definition: elog.h:141
amrescan_function amrescan
Definition: amapi.h:222
RegProcedure * rd_support
Definition: rel.h:160
int64 index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
Definition: indexam.c:652
void UnregisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:907
float float4
Definition: c.h:491
Size EstimateSnapshotSpace(Snapshot snap)
Definition: snapmgr.c:2078
#define MAX_LOCKMODES
Definition: lock.h:85
struct ParallelIndexScanDescData * parallel_scan
Definition: relscan.h:151
void RelationIncrementReferenceCount(Relation rel)
Definition: relcache.c:2055
void index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes, IndexOrderByDistance *distances, bool recheckOrderBy)
Definition: indexam.c:849
IndexBulkDeleteResult * index_bulk_delete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats, IndexBulkDeleteCallback callback, void *callback_state)
Definition: indexam.c:682
uintptr_t Datum
Definition: postgres.h:367
Size add_size(Size s1, Size s2)
Definition: shmem.c:475
static bool table_index_fetch_tuple(struct IndexFetchTableData *scan, ItemPointer tid, Snapshot snapshot, TupleTableSlot *slot, bool *call_again, bool *all_dead)
Definition: tableam.h:981
#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
static void table_index_fetch_reset(struct IndexFetchTableData *scan)
Definition: tableam.h:944
static IndexScanDesc index_beginscan_internal(Relation indexRelation, int nkeys, int norderbys, Snapshot snapshot, ParallelIndexScanDesc pscan, bool temp_snap)
Definition: indexam.c:247
#define Assert(condition)
Definition: c.h:733
IndexFetchTableData * xs_heapfetch
Definition: relscan.h:135
size_t Size
Definition: c.h:467
#define SCAN_CHECKS
Definition: indexam.c:80
bool index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
Definition: indexam.c:607
#define MAXALIGN(LEN)
Definition: c.h:686
bool xs_heap_continue
Definition: relscan.h:133
ammarkpos_function ammarkpos
Definition: amapi.h:226
#define pgstat_count_index_tuples(rel, n)
Definition: pgstat.h:1378
IndexBulkDeleteResult * index_vacuum_cleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
Definition: indexam.c:703
amestimateparallelscan_function amestimateparallelscan
Definition: amapi.h:230
bool ItemPointerEquals(ItemPointer pointer1, ItemPointer pointer2)
Definition: itemptr.c:29
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:152
#define DatumGetPointer(X)
Definition: postgres.h:549
static Datum values[MAXATTR]
Definition: bootstrap.c:167
int errmsg(const char *fmt,...)
Definition: elog.c:822
void index_parallelscan_initialize(Relation heapRelation, Relation indexRelation, Snapshot snapshot, ParallelIndexScanDesc target)
Definition: indexam.c:427
#define elog(elevel,...)
Definition: elog.h:228
MemoryContext rd_indexcxt
Definition: rel.h:155
int i
bool kill_prior_tuple
Definition: relscan.h:113
bool index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
Definition: indexam.c:566
int numberOfOrderBys
Definition: relscan.h:106
#define TransactionIdIsValid(xid)
Definition: transam.h:41
static void table_index_fetch_end(struct IndexFetchTableData *scan)
Definition: tableam.h:953
amcanreturn_function amcanreturn
Definition: amapi.h:215
int16 AttrNumber
Definition: attnum.h:21
#define RelationGetRelid(relation)
Definition: rel.h:423
Relation index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:126
#define offsetof(type, field)
Definition: c.h:656
bool(* IndexBulkDeleteCallback)(ItemPointer itemptr, void *state)
Definition: genam.h:84
aminitparallelscan_function aminitparallelscan
Definition: amapi.h:231
bool index_insert(Relation indexRelation, Datum *values, bool *isnull, ItemPointer heap_t_ctid, Relation heapRelation, IndexUniqueCheck checkUnique, IndexInfo *indexInfo)
Definition: indexam.c:170
IndexScanDesc index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, int norderbys)
Definition: indexam.c:197
amrestrpos_function amrestrpos
Definition: amapi.h:227
RegProcedure index_getprocid(Relation irel, AttrNumber attnum, uint16 procnum)
Definition: indexam.c:760