Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * indexam.c
4 : * general index access method routines
5 : *
6 : * Portions Copyright (c) 1996-2026, 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/lock.h"
57 : #include "storage/predicate.h"
58 : #include "utils/ruleutils.h"
59 : #include "utils/snapmgr.h"
60 : #include "utils/syscache.h"
61 :
62 :
63 : /* ----------------------------------------------------------------
64 : * macros used in index_ routines
65 : *
66 : * Note: the ReindexIsProcessingIndex() check in RELATION_CHECKS is there
67 : * to check that we don't try to scan or do retail insertions into an index
68 : * that is currently being rebuilt or pending rebuild. This helps to catch
69 : * things that don't work when reindexing system catalogs, as well as prevent
70 : * user errors like index expressions that access their own tables. The check
71 : * doesn't prevent the actual rebuild because we don't use RELATION_CHECKS
72 : * when calling the index AM's ambuild routine, and there is no reason for
73 : * ambuild to call its subsidiary routines through this file.
74 : * ----------------------------------------------------------------
75 : */
76 : #define RELATION_CHECKS \
77 : do { \
78 : Assert(RelationIsValid(indexRelation)); \
79 : Assert(indexRelation->rd_indam); \
80 : if (unlikely(ReindexIsProcessingIndex(RelationGetRelid(indexRelation)))) \
81 : ereport(ERROR, \
82 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), \
83 : errmsg("cannot access index \"%s\" while it is being reindexed", \
84 : RelationGetRelationName(indexRelation)))); \
85 : } while(0)
86 :
87 : #define SCAN_CHECKS \
88 : ( \
89 : AssertMacro(scan), \
90 : AssertMacro(RelationIsValid(scan->indexRelation)), \
91 : AssertMacro(scan->indexRelation->rd_indam) \
92 : )
93 :
94 : #define CHECK_REL_PROCEDURE(pname) \
95 : do { \
96 : if (indexRelation->rd_indam->pname == NULL) \
97 : elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
98 : CppAsString(pname), RelationGetRelationName(indexRelation)); \
99 : } while(0)
100 :
101 : #define CHECK_SCAN_PROCEDURE(pname) \
102 : do { \
103 : if (scan->indexRelation->rd_indam->pname == NULL) \
104 : elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
105 : CppAsString(pname), RelationGetRelationName(scan->indexRelation)); \
106 : } while(0)
107 :
108 : static IndexScanDesc index_beginscan_internal(Relation indexRelation,
109 : int nkeys, int norderbys, Snapshot snapshot,
110 : ParallelIndexScanDesc pscan, bool temp_snap);
111 : static inline void validate_relation_as_index(Relation r);
112 :
113 :
114 : /* ----------------------------------------------------------------
115 : * index_ interface functions
116 : * ----------------------------------------------------------------
117 : */
118 :
119 : /* ----------------
120 : * index_open - open an index relation by relation OID
121 : *
122 : * If lockmode is not "NoLock", the specified kind of lock is
123 : * obtained on the index. (Generally, NoLock should only be
124 : * used if the caller knows it has some appropriate lock on the
125 : * index already.)
126 : *
127 : * An error is raised if the index does not exist.
128 : *
129 : * This is a convenience routine adapted for indexscan use.
130 : * Some callers may prefer to use relation_open directly.
131 : * ----------------
132 : */
133 : Relation
134 13200012 : index_open(Oid relationId, LOCKMODE lockmode)
135 : {
136 : Relation r;
137 :
138 13200012 : r = relation_open(relationId, lockmode);
139 :
140 13200007 : validate_relation_as_index(r);
141 :
142 13199993 : return r;
143 : }
144 :
145 : /* ----------------
146 : * try_index_open - open an index relation by relation OID
147 : *
148 : * Same as index_open, except return NULL instead of failing
149 : * if the relation does not exist.
150 : * ----------------
151 : */
152 : Relation
153 1175 : try_index_open(Oid relationId, LOCKMODE lockmode)
154 : {
155 : Relation r;
156 :
157 1175 : r = try_relation_open(relationId, lockmode);
158 :
159 : /* leave if index does not exist */
160 1175 : if (!r)
161 0 : return NULL;
162 :
163 1175 : validate_relation_as_index(r);
164 :
165 1175 : return r;
166 : }
167 :
168 : /* ----------------
169 : * index_close - close an index relation
170 : *
171 : * If lockmode is not "NoLock", we then release the specified lock.
172 : *
173 : * Note that it is often sensible to hold a lock beyond index_close;
174 : * in that case, the lock is released automatically at xact end.
175 : * ----------------
176 : */
177 : void
178 13228539 : index_close(Relation relation, LOCKMODE lockmode)
179 : {
180 13228539 : LockRelId relid = relation->rd_lockInfo.lockRelId;
181 :
182 : Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
183 :
184 : /* The relcache does the real work... */
185 13228539 : RelationClose(relation);
186 :
187 13228539 : if (lockmode != NoLock)
188 12047878 : UnlockRelationId(&relid, lockmode);
189 13228539 : }
190 :
191 : /* ----------------
192 : * validate_relation_as_index
193 : *
194 : * Make sure relkind is an index or a partitioned index.
195 : * ----------------
196 : */
197 : static inline void
198 13201182 : validate_relation_as_index(Relation r)
199 : {
200 13201182 : if (r->rd_rel->relkind != RELKIND_INDEX &&
201 8579 : r->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
202 14 : ereport(ERROR,
203 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
204 : errmsg("\"%s\" is not an index",
205 : RelationGetRelationName(r))));
206 13201168 : }
207 :
208 :
209 : /* ----------------
210 : * index_insert - insert an index tuple into a relation
211 : * ----------------
212 : */
213 : bool
214 5900059 : index_insert(Relation indexRelation,
215 : Datum *values,
216 : bool *isnull,
217 : ItemPointer heap_t_ctid,
218 : Relation heapRelation,
219 : IndexUniqueCheck checkUnique,
220 : bool indexUnchanged,
221 : IndexInfo *indexInfo)
222 : {
223 5900059 : RELATION_CHECKS;
224 5900059 : CHECK_REL_PROCEDURE(aminsert);
225 :
226 5900059 : if (!(indexRelation->rd_indam->ampredlocks))
227 333627 : CheckForSerializableConflictIn(indexRelation,
228 : (ItemPointer) NULL,
229 : InvalidBlockNumber);
230 :
231 5900059 : return indexRelation->rd_indam->aminsert(indexRelation, values, isnull,
232 : heap_t_ctid, heapRelation,
233 : checkUnique, indexUnchanged,
234 : indexInfo);
235 : }
236 :
237 : /* -------------------------
238 : * index_insert_cleanup - clean up after all index inserts are done
239 : * -------------------------
240 : */
241 : void
242 2275403 : index_insert_cleanup(Relation indexRelation,
243 : IndexInfo *indexInfo)
244 : {
245 2275403 : RELATION_CHECKS;
246 :
247 2275403 : if (indexRelation->rd_indam->aminsertcleanup)
248 740 : indexRelation->rd_indam->aminsertcleanup(indexRelation, indexInfo);
249 2275403 : }
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 : */
256 : IndexScanDesc
257 9836706 : index_beginscan(Relation heapRelation,
258 : Relation indexRelation,
259 : Snapshot snapshot,
260 : IndexScanInstrumentation *instrument,
261 : int nkeys, int norderbys,
262 : uint32 flags)
263 : {
264 : IndexScanDesc scan;
265 :
266 : Assert(snapshot != InvalidSnapshot);
267 :
268 : /* Check that a historic snapshot is not used for non-catalog tables */
269 9836706 : if (IsHistoricMVCCSnapshot(snapshot) &&
270 17349 : !RelationIsAccessibleInLogicalDecoding(heapRelation))
271 : {
272 0 : ereport(ERROR,
273 : (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
274 : errmsg("cannot query non-catalog table \"%s\" during logical decoding",
275 : RelationGetRelationName(heapRelation))));
276 : }
277 :
278 9836706 : scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
279 :
280 : /*
281 : * Save additional parameters into the scandesc. Everything else was set
282 : * up by RelationGetIndexScan.
283 : */
284 9836706 : scan->heapRelation = heapRelation;
285 9836706 : scan->xs_snapshot = snapshot;
286 9836706 : scan->instrument = instrument;
287 :
288 : /* prepare to fetch index matches from table */
289 9836706 : scan->xs_heapfetch = table_index_fetch_begin(heapRelation, flags);
290 :
291 9836706 : return scan;
292 : }
293 :
294 : /*
295 : * index_beginscan_bitmap - start a scan of an index with amgetbitmap
296 : *
297 : * As above, caller had better be holding some lock on the parent heap
298 : * relation, even though it's not explicitly mentioned here.
299 : */
300 : IndexScanDesc
301 14545 : index_beginscan_bitmap(Relation indexRelation,
302 : Snapshot snapshot,
303 : IndexScanInstrumentation *instrument,
304 : int nkeys)
305 : {
306 : IndexScanDesc scan;
307 :
308 : Assert(snapshot != InvalidSnapshot);
309 :
310 14545 : scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
311 :
312 : /*
313 : * Save additional parameters into the scandesc. Everything else was set
314 : * up by RelationGetIndexScan.
315 : */
316 14545 : scan->xs_snapshot = snapshot;
317 14545 : scan->instrument = instrument;
318 :
319 14545 : return scan;
320 : }
321 :
322 : /*
323 : * index_beginscan_internal --- common code for index_beginscan variants
324 : */
325 : static IndexScanDesc
326 9851509 : index_beginscan_internal(Relation indexRelation,
327 : int nkeys, int norderbys, Snapshot snapshot,
328 : ParallelIndexScanDesc pscan, bool temp_snap)
329 : {
330 : IndexScanDesc scan;
331 :
332 9851509 : RELATION_CHECKS;
333 9851509 : CHECK_REL_PROCEDURE(ambeginscan);
334 :
335 9851509 : if (!(indexRelation->rd_indam->ampredlocks))
336 2953 : PredicateLockRelation(indexRelation, snapshot);
337 :
338 : /*
339 : * We hold a reference count to the relcache entry throughout the scan.
340 : */
341 9851509 : RelationIncrementReferenceCount(indexRelation);
342 :
343 : /*
344 : * Tell the AM to open a scan.
345 : */
346 9851509 : scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
347 : norderbys);
348 : /* Initialize information for parallel scan. */
349 9851509 : scan->parallel_scan = pscan;
350 9851509 : scan->xs_temp_snap = temp_snap;
351 :
352 9851509 : return scan;
353 : }
354 :
355 : /* ----------------
356 : * index_rescan - (re)start a scan of an index
357 : *
358 : * During a restart, the caller may specify a new set of scankeys and/or
359 : * orderbykeys; but the number of keys cannot differ from what index_beginscan
360 : * was told. (Later we might relax that to "must not exceed", but currently
361 : * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
362 : * To restart the scan without changing keys, pass NULL for the key arrays.
363 : * (Of course, keys *must* be passed on the first call, unless
364 : * scan->numberOfKeys is zero.)
365 : * ----------------
366 : */
367 : void
368 10320399 : index_rescan(IndexScanDesc scan,
369 : ScanKey keys, int nkeys,
370 : ScanKey orderbys, int norderbys)
371 : {
372 : SCAN_CHECKS;
373 10320399 : CHECK_SCAN_PROCEDURE(amrescan);
374 :
375 : Assert(nkeys == scan->numberOfKeys);
376 : Assert(norderbys == scan->numberOfOrderBys);
377 :
378 : /* reset table AM state for rescan */
379 10320399 : if (scan->xs_heapfetch)
380 10303522 : table_index_fetch_reset(scan->xs_heapfetch);
381 :
382 10320399 : scan->kill_prior_tuple = false; /* for safety */
383 10320399 : scan->xs_heap_continue = false;
384 :
385 10320399 : scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
386 : orderbys, norderbys);
387 10320399 : }
388 :
389 : /* ----------------
390 : * index_endscan - end a scan
391 : * ----------------
392 : */
393 : void
394 9850223 : index_endscan(IndexScanDesc scan)
395 : {
396 : SCAN_CHECKS;
397 9850223 : CHECK_SCAN_PROCEDURE(amendscan);
398 :
399 : /* Release resources (like buffer pins) from table accesses */
400 9850223 : if (scan->xs_heapfetch)
401 : {
402 9835759 : table_index_fetch_end(scan->xs_heapfetch);
403 9835759 : scan->xs_heapfetch = NULL;
404 : }
405 :
406 : /* End the AM's scan */
407 9850223 : scan->indexRelation->rd_indam->amendscan(scan);
408 :
409 : /* Release index refcount acquired by index_beginscan */
410 9850223 : RelationDecrementReferenceCount(scan->indexRelation);
411 :
412 9850223 : if (scan->xs_temp_snap)
413 258 : UnregisterSnapshot(scan->xs_snapshot);
414 :
415 : /* Release the scan data structure itself */
416 9850223 : IndexScanEnd(scan);
417 9850223 : }
418 :
419 : /* ----------------
420 : * index_markpos - mark a scan position
421 : * ----------------
422 : */
423 : void
424 86084 : index_markpos(IndexScanDesc scan)
425 : {
426 : SCAN_CHECKS;
427 86084 : CHECK_SCAN_PROCEDURE(ammarkpos);
428 :
429 86084 : scan->indexRelation->rd_indam->ammarkpos(scan);
430 86084 : }
431 :
432 : /* ----------------
433 : * index_restrpos - restore a scan position
434 : *
435 : * NOTE: this only restores the internal scan state of the index AM. See
436 : * comments for ExecRestrPos().
437 : *
438 : * NOTE: For heap, in the presence of HOT chains, mark/restore only works
439 : * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
440 : * most one returnable tuple in each HOT chain, and so restoring the prior
441 : * state at the granularity of the index AM is sufficient. Since the only
442 : * current user of mark/restore functionality is nodeMergejoin.c, this
443 : * effectively means that merge-join plans only work for MVCC snapshots. This
444 : * could be fixed if necessary, but for now it seems unimportant.
445 : * ----------------
446 : */
447 : void
448 36024 : index_restrpos(IndexScanDesc scan)
449 : {
450 : Assert(IsMVCCLikeSnapshot(scan->xs_snapshot));
451 :
452 : SCAN_CHECKS;
453 36024 : CHECK_SCAN_PROCEDURE(amrestrpos);
454 :
455 : /* reset table AM state for restoring the marked position */
456 36024 : if (scan->xs_heapfetch)
457 36024 : table_index_fetch_reset(scan->xs_heapfetch);
458 :
459 36024 : scan->kill_prior_tuple = false; /* for safety */
460 36024 : scan->xs_heap_continue = false;
461 :
462 36024 : scan->indexRelation->rd_indam->amrestrpos(scan);
463 36024 : }
464 :
465 : /*
466 : * Estimates the shared memory needed for parallel scan, including any
467 : * AM-specific parallel scan state.
468 : */
469 : Size
470 42 : index_parallelscan_estimate(Relation indexRelation, int nkeys, int norderbys,
471 : Snapshot snapshot)
472 : {
473 : Size nbytes;
474 :
475 42 : RELATION_CHECKS;
476 :
477 42 : nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
478 42 : nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
479 42 : nbytes = MAXALIGN(nbytes);
480 :
481 : /*
482 : * If parallel scan index AM interface can't be used (or index AM provides
483 : * no such interface), assume there is no AM-specific data needed
484 : */
485 42 : if (indexRelation->rd_indam->amestimateparallelscan != NULL)
486 42 : nbytes = add_size(nbytes,
487 42 : indexRelation->rd_indam->amestimateparallelscan(indexRelation,
488 : nkeys,
489 : norderbys));
490 :
491 42 : return nbytes;
492 : }
493 :
494 : /*
495 : * index_parallelscan_initialize - initialize parallel scan
496 : *
497 : * We initialize both the ParallelIndexScanDesc proper and the AM-specific
498 : * information which follows it.
499 : *
500 : * This function calls access method specific initialization routine to
501 : * initialize am specific information. Call this just once in the leader
502 : * process; then, individual workers attach via index_beginscan_parallel.
503 : */
504 : void
505 42 : index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
506 : Snapshot snapshot,
507 : ParallelIndexScanDesc target)
508 : {
509 : Size offset;
510 :
511 42 : RELATION_CHECKS;
512 :
513 42 : offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
514 : EstimateSnapshotSpace(snapshot));
515 42 : offset = MAXALIGN(offset);
516 :
517 42 : target->ps_locator = heapRelation->rd_locator;
518 42 : target->ps_indexlocator = indexRelation->rd_locator;
519 42 : target->ps_offset_am = 0;
520 42 : SerializeSnapshot(snapshot, target->ps_snapshot_data);
521 :
522 : /* aminitparallelscan is optional; assume no-op if not provided by AM */
523 42 : if (indexRelation->rd_indam->aminitparallelscan != NULL)
524 : {
525 : void *amtarget;
526 :
527 42 : target->ps_offset_am = offset;
528 42 : amtarget = OffsetToPointer(target, target->ps_offset_am);
529 42 : indexRelation->rd_indam->aminitparallelscan(amtarget);
530 : }
531 42 : }
532 :
533 : /* ----------------
534 : * index_parallelrescan - (re)start a parallel scan of an index
535 : * ----------------
536 : */
537 : void
538 16 : index_parallelrescan(IndexScanDesc scan)
539 : {
540 : SCAN_CHECKS;
541 :
542 : /* reset table AM state for rescan */
543 16 : if (scan->xs_heapfetch)
544 16 : table_index_fetch_reset(scan->xs_heapfetch);
545 :
546 : /* amparallelrescan is optional; assume no-op if not provided by AM */
547 16 : if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
548 16 : scan->indexRelation->rd_indam->amparallelrescan(scan);
549 16 : }
550 :
551 : /*
552 : * index_beginscan_parallel - join parallel index scan
553 : *
554 : * flags is a bitmask of ScanOptions affecting the underlying table scan. No
555 : * SO_INTERNAL_FLAGS are permitted.
556 : *
557 : * Caller must be holding suitable locks on the heap and the index.
558 : */
559 : IndexScanDesc
560 258 : index_beginscan_parallel(Relation heaprel, Relation indexrel,
561 : IndexScanInstrumentation *instrument,
562 : int nkeys, int norderbys,
563 : ParallelIndexScanDesc pscan,
564 : uint32 flags)
565 : {
566 : Snapshot snapshot;
567 : IndexScanDesc scan;
568 :
569 : Assert(RelFileLocatorEquals(heaprel->rd_locator, pscan->ps_locator));
570 : Assert(RelFileLocatorEquals(indexrel->rd_locator, pscan->ps_indexlocator));
571 :
572 258 : snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
573 258 : RegisterSnapshot(snapshot);
574 258 : scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
575 : pscan, true);
576 :
577 : /*
578 : * Save additional parameters into the scandesc. Everything else was set
579 : * up by index_beginscan_internal.
580 : */
581 258 : scan->heapRelation = heaprel;
582 258 : scan->xs_snapshot = snapshot;
583 258 : scan->instrument = instrument;
584 :
585 : /* prepare to fetch index matches from table */
586 258 : scan->xs_heapfetch = table_index_fetch_begin(heaprel, flags);
587 :
588 258 : return scan;
589 : }
590 :
591 : /* ----------------
592 : * index_getnext_tid - get the next TID from a scan
593 : *
594 : * The result is the next TID satisfying the scan keys,
595 : * or NULL if no more matching tuples exist.
596 : * ----------------
597 : */
598 : ItemPointer
599 24581096 : index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
600 : {
601 : bool found;
602 :
603 : SCAN_CHECKS;
604 24581096 : CHECK_SCAN_PROCEDURE(amgettuple);
605 :
606 : /* XXX: we should assert that a snapshot is pushed or registered */
607 : Assert(TransactionIdIsValid(RecentXmin));
608 :
609 : /*
610 : * The AM's amgettuple proc finds the next index entry matching the scan
611 : * keys, and puts the TID into scan->xs_heaptid. It should also set
612 : * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
613 : * pay no attention to those fields here.
614 : */
615 24581096 : found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
616 :
617 : /* Reset kill flag immediately for safety */
618 24581096 : scan->kill_prior_tuple = false;
619 24581096 : scan->xs_heap_continue = false;
620 :
621 : /* If we're out of index entries, we're done */
622 24581096 : if (!found)
623 : {
624 : /* reset table AM state */
625 4493130 : if (scan->xs_heapfetch)
626 4493130 : table_index_fetch_reset(scan->xs_heapfetch);
627 :
628 4493130 : return NULL;
629 : }
630 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
631 :
632 20087966 : pgstat_count_index_tuples(scan->indexRelation, 1);
633 :
634 : /* Return the TID of the tuple we found. */
635 20087966 : return &scan->xs_heaptid;
636 : }
637 :
638 : /* ----------------
639 : * index_fetch_heap - get the scan's next heap tuple
640 : *
641 : * The result is a visible heap tuple associated with the index TID most
642 : * recently fetched by index_getnext_tid, or NULL if no more matching tuples
643 : * exist. (There can be more than one matching tuple because of HOT chains,
644 : * although when using an MVCC snapshot it should be impossible for more than
645 : * one such tuple to exist.)
646 : *
647 : * On success, the buffer containing the heap tup is pinned (the pin will be
648 : * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
649 : * call).
650 : *
651 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
652 : * scan keys if required. We do not do that here because we don't have
653 : * enough information to do it efficiently in the general case.
654 : * ----------------
655 : */
656 : bool
657 16910985 : index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
658 : {
659 16910985 : bool all_dead = false;
660 : bool found;
661 :
662 16910985 : found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
663 : scan->xs_snapshot, slot,
664 : &scan->xs_heap_continue, &all_dead);
665 :
666 16910980 : if (found)
667 16192821 : pgstat_count_heap_fetch(scan->indexRelation);
668 :
669 : /*
670 : * If we scanned a whole HOT chain and found only dead tuples, tell index
671 : * AM to kill its entry for that TID (this will take effect in the next
672 : * amgettuple call, in index_getnext_tid). We do not do this when in
673 : * recovery because it may violate MVCC to do so. See comments in
674 : * RelationGetIndexScan().
675 : */
676 16910980 : if (!scan->xactStartedInRecovery)
677 16633327 : scan->kill_prior_tuple = all_dead;
678 :
679 16910980 : return found;
680 : }
681 :
682 : /* ----------------
683 : * index_getnext_slot - get the next tuple from a scan
684 : *
685 : * The result is true if a tuple satisfying the scan keys and the snapshot was
686 : * found, false otherwise. The tuple is stored in the specified slot.
687 : *
688 : * On success, resources (like buffer pins) are likely to be held, and will be
689 : * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
690 : * call).
691 : *
692 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
693 : * scan keys if required. We do not do that here because we don't have
694 : * enough information to do it efficiently in the general case.
695 : * ----------------
696 : */
697 : bool
698 20059829 : index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
699 : {
700 : for (;;)
701 : {
702 20655170 : if (!scan->xs_heap_continue)
703 : {
704 : ItemPointer tid;
705 :
706 : /* Time to fetch the next TID from the index */
707 20556479 : tid = index_getnext_tid(scan, direction);
708 :
709 : /* If we're out of index entries, we're done */
710 20556479 : if (tid == NULL)
711 4358158 : break;
712 :
713 : Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
714 : }
715 :
716 : /*
717 : * Fetch the next (or only) visible heap tuple for this index entry.
718 : * If we don't find anything, loop around and grab the next TID from
719 : * the index.
720 : */
721 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
722 16297012 : if (index_fetch_heap(scan, slot))
723 15701666 : return true;
724 : }
725 :
726 4358158 : return false;
727 : }
728 :
729 : /* ----------------
730 : * index_getbitmap - get all tuples at once from an index scan
731 : *
732 : * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
733 : * Since there's no interlock between the index scan and the eventual heap
734 : * access, this is only safe to use with MVCC-based snapshots: the heap
735 : * item slot could have been replaced by a newer tuple by the time we get
736 : * to it.
737 : *
738 : * Returns the number of matching tuples found. (Note: this might be only
739 : * approximate, so it should only be used for statistical purposes.)
740 : * ----------------
741 : */
742 : int64
743 16085 : index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
744 : {
745 : int64 ntids;
746 :
747 : SCAN_CHECKS;
748 16085 : CHECK_SCAN_PROCEDURE(amgetbitmap);
749 :
750 : /* just make sure this is false... */
751 16085 : scan->kill_prior_tuple = false;
752 :
753 : /*
754 : * have the am's getbitmap proc do all the work.
755 : */
756 16085 : ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
757 :
758 16085 : pgstat_count_index_tuples(scan->indexRelation, ntids);
759 :
760 16085 : return ntids;
761 : }
762 :
763 : /* ----------------
764 : * index_bulk_delete - do mass deletion of index entries
765 : *
766 : * callback routine tells whether a given main-heap tuple is
767 : * to be deleted
768 : *
769 : * return value is an optional palloc'd struct of statistics
770 : * ----------------
771 : */
772 : IndexBulkDeleteResult *
773 1963 : index_bulk_delete(IndexVacuumInfo *info,
774 : IndexBulkDeleteResult *istat,
775 : IndexBulkDeleteCallback callback,
776 : void *callback_state)
777 : {
778 1963 : Relation indexRelation = info->index;
779 :
780 1963 : RELATION_CHECKS;
781 1963 : CHECK_REL_PROCEDURE(ambulkdelete);
782 :
783 1963 : return indexRelation->rd_indam->ambulkdelete(info, istat,
784 : callback, callback_state);
785 : }
786 :
787 : /* ----------------
788 : * index_vacuum_cleanup - do post-deletion cleanup of an index
789 : *
790 : * return value is an optional palloc'd struct of statistics
791 : * ----------------
792 : */
793 : IndexBulkDeleteResult *
794 150757 : index_vacuum_cleanup(IndexVacuumInfo *info,
795 : IndexBulkDeleteResult *istat)
796 : {
797 150757 : Relation indexRelation = info->index;
798 :
799 150757 : RELATION_CHECKS;
800 150757 : CHECK_REL_PROCEDURE(amvacuumcleanup);
801 :
802 150757 : return indexRelation->rd_indam->amvacuumcleanup(info, istat);
803 : }
804 :
805 : /* ----------------
806 : * index_can_return
807 : *
808 : * Does the index access method support index-only scans for the given
809 : * column?
810 : * ----------------
811 : */
812 : bool
813 1097146 : index_can_return(Relation indexRelation, int attno)
814 : {
815 1097146 : RELATION_CHECKS;
816 :
817 : /* amcanreturn is optional; assume false if not provided by AM */
818 1097146 : if (indexRelation->rd_indam->amcanreturn == NULL)
819 226925 : return false;
820 :
821 870221 : return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
822 : }
823 :
824 : /* ----------------
825 : * index_getprocid
826 : *
827 : * Index access methods typically require support routines that are
828 : * not directly the implementation of any WHERE-clause query operator
829 : * and so cannot be kept in pg_amop. Instead, such routines are kept
830 : * in pg_amproc. These registered procedure OIDs are assigned numbers
831 : * according to a convention established by the access method.
832 : * The general index code doesn't know anything about the routines
833 : * involved; it just builds an ordered list of them for
834 : * each attribute on which an index is defined.
835 : *
836 : * As of Postgres 8.3, support routines within an operator family
837 : * are further subdivided by the "left type" and "right type" of the
838 : * query operator(s) that they support. The "default" functions for a
839 : * particular indexed attribute are those with both types equal to
840 : * the index opclass' opcintype (note that this is subtly different
841 : * from the indexed attribute's own type: it may be a binary-compatible
842 : * type instead). Only the default functions are stored in relcache
843 : * entries --- access methods can use the syscache to look up non-default
844 : * functions.
845 : *
846 : * This routine returns the requested default procedure OID for a
847 : * particular indexed attribute.
848 : * ----------------
849 : */
850 : RegProcedure
851 1342296 : index_getprocid(Relation irel,
852 : AttrNumber attnum,
853 : uint16 procnum)
854 : {
855 : RegProcedure *loc;
856 : int nproc;
857 : int procindex;
858 :
859 1342296 : nproc = irel->rd_indam->amsupport;
860 :
861 : Assert(procnum > 0 && procnum <= (uint16) nproc);
862 :
863 1342296 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
864 :
865 1342296 : loc = irel->rd_support;
866 :
867 : Assert(loc != NULL);
868 :
869 1342296 : return loc[procindex];
870 : }
871 :
872 : /* ----------------
873 : * index_getprocinfo
874 : *
875 : * This routine allows index AMs to keep fmgr lookup info for
876 : * support procs in the relcache. As above, only the "default"
877 : * functions for any particular indexed attribute are cached.
878 : *
879 : * Note: the return value points into cached data that will be lost during
880 : * any relcache rebuild! Therefore, either use the callinfo right away,
881 : * or save it only after having acquired some type of lock on the index rel.
882 : * ----------------
883 : */
884 : FmgrInfo *
885 31049693 : index_getprocinfo(Relation irel,
886 : AttrNumber attnum,
887 : uint16 procnum)
888 : {
889 : FmgrInfo *locinfo;
890 : int nproc;
891 : int optsproc;
892 : int procindex;
893 :
894 31049693 : nproc = irel->rd_indam->amsupport;
895 31049693 : optsproc = irel->rd_indam->amoptsprocnum;
896 :
897 : Assert(procnum > 0 && procnum <= (uint16) nproc);
898 :
899 31049693 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
900 :
901 31049693 : locinfo = irel->rd_supportinfo;
902 :
903 : Assert(locinfo != NULL);
904 :
905 31049693 : locinfo += procindex;
906 :
907 : /* Initialize the lookup info if first time through */
908 31049693 : if (locinfo->fn_oid == InvalidOid)
909 : {
910 683502 : RegProcedure *loc = irel->rd_support;
911 : RegProcedure procId;
912 :
913 : Assert(loc != NULL);
914 :
915 683502 : procId = loc[procindex];
916 :
917 : /*
918 : * Complain if function was not found during IndexSupportInitialize.
919 : * This should not happen unless the system tables contain bogus
920 : * entries for the index opclass. (If an AM wants to allow a support
921 : * function to be optional, it can use index_getprocid.)
922 : */
923 683502 : if (!RegProcedureIsValid(procId))
924 0 : elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
925 : procnum, attnum, RelationGetRelationName(irel));
926 :
927 683502 : fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
928 :
929 683502 : if (procnum != optsproc)
930 : {
931 : /* Initialize locinfo->fn_expr with opclass options Const */
932 682356 : bytea **attoptions = RelationGetIndexAttOptions(irel, false);
933 682356 : MemoryContext oldcxt = MemoryContextSwitchTo(irel->rd_indexcxt);
934 :
935 682356 : set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
936 :
937 682356 : MemoryContextSwitchTo(oldcxt);
938 : }
939 : }
940 :
941 31049693 : return locinfo;
942 : }
943 :
944 : /* ----------------
945 : * index_store_float8_orderby_distances
946 : *
947 : * Convert AM distance function's results (that can be inexact)
948 : * to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
949 : * for a possible recheck.
950 : * ----------------
951 : */
952 : void
953 242999 : index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
954 : IndexOrderByDistance *distances,
955 : bool recheckOrderBy)
956 : {
957 : int i;
958 :
959 : Assert(distances || !recheckOrderBy);
960 :
961 242999 : scan->xs_recheckorderby = recheckOrderBy;
962 :
963 486010 : for (i = 0; i < scan->numberOfOrderBys; i++)
964 : {
965 243011 : if (orderByTypes[i] == FLOAT8OID)
966 : {
967 242946 : if (distances && !distances[i].isnull)
968 : {
969 242906 : scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
970 242906 : scan->xs_orderbynulls[i] = false;
971 : }
972 : else
973 : {
974 40 : scan->xs_orderbyvals[i] = (Datum) 0;
975 40 : scan->xs_orderbynulls[i] = true;
976 : }
977 : }
978 65 : else if (orderByTypes[i] == FLOAT4OID)
979 : {
980 : /* convert distance function's result to ORDER BY type */
981 35 : if (distances && !distances[i].isnull)
982 : {
983 35 : scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
984 35 : scan->xs_orderbynulls[i] = false;
985 : }
986 : else
987 : {
988 0 : scan->xs_orderbyvals[i] = (Datum) 0;
989 0 : scan->xs_orderbynulls[i] = true;
990 : }
991 : }
992 : else
993 : {
994 : /*
995 : * If the ordering operator's return value is anything else, we
996 : * don't know how to convert the float8 bound calculated by the
997 : * distance function to that. The executor won't actually need
998 : * the order by values we return here, if there are no lossy
999 : * results, so only insist on converting if the *recheck flag is
1000 : * set.
1001 : */
1002 30 : if (scan->xs_recheckorderby)
1003 0 : elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
1004 30 : scan->xs_orderbynulls[i] = true;
1005 : }
1006 : }
1007 242999 : }
1008 :
1009 : /* ----------------
1010 : * index_opclass_options
1011 : *
1012 : * Parse opclass-specific options for index column.
1013 : * ----------------
1014 : */
1015 : bytea *
1016 720866 : index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
1017 : bool validate)
1018 : {
1019 720866 : int amoptsprocnum = indrel->rd_indam->amoptsprocnum;
1020 720866 : Oid procid = InvalidOid;
1021 : FmgrInfo *procinfo;
1022 : local_relopts relopts;
1023 :
1024 : /* fetch options support procedure if specified */
1025 720866 : if (amoptsprocnum != 0)
1026 720832 : procid = index_getprocid(indrel, attnum, amoptsprocnum);
1027 :
1028 720866 : if (!OidIsValid(procid))
1029 : {
1030 : Oid opclass;
1031 : Datum indclassDatum;
1032 : oidvector *indclass;
1033 :
1034 719257 : if (!DatumGetPointer(attoptions))
1035 719253 : return NULL; /* ok, no options, no procedure */
1036 :
1037 : /*
1038 : * Report an error if the opclass's options-parsing procedure does not
1039 : * exist but the opclass options are specified.
1040 : */
1041 4 : indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indrel->rd_indextuple,
1042 : Anum_pg_index_indclass);
1043 4 : indclass = (oidvector *) DatumGetPointer(indclassDatum);
1044 4 : opclass = indclass->values[attnum - 1];
1045 :
1046 4 : ereport(ERROR,
1047 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1048 : errmsg("operator class %s has no options",
1049 : generate_opclass_name(opclass))));
1050 : }
1051 :
1052 1609 : init_local_reloptions(&relopts, 0);
1053 :
1054 1609 : procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
1055 :
1056 1609 : (void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
1057 :
1058 1609 : return build_local_reloptions(&relopts, attoptions, validate);
1059 : }
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