Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * execIndexing.c
4 : : * routines for inserting index tuples and enforcing unique and
5 : : * exclusion constraints.
6 : : *
7 : : * ExecInsertIndexTuples() is the main entry point. It's called after
8 : : * inserting a tuple to the heap, and it inserts corresponding index tuples
9 : : * into all indexes. At the same time, it enforces any unique and
10 : : * exclusion constraints:
11 : : *
12 : : * Unique Indexes
13 : : * --------------
14 : : *
15 : : * Enforcing a unique constraint is straightforward. When the index AM
16 : : * inserts the tuple to the index, it also checks that there are no
17 : : * conflicting tuples in the index already. It does so atomically, so that
18 : : * even if two backends try to insert the same key concurrently, only one
19 : : * of them will succeed. All the logic to ensure atomicity, and to wait
20 : : * for in-progress transactions to finish, is handled by the index AM.
21 : : *
22 : : * If a unique constraint is deferred, we request the index AM to not
23 : : * throw an error if a conflict is found. Instead, we make note that there
24 : : * was a conflict and return the list of indexes with conflicts to the
25 : : * caller. The caller must re-check them later, by calling index_insert()
26 : : * with the UNIQUE_CHECK_EXISTING option.
27 : : *
28 : : * Exclusion Constraints
29 : : * ---------------------
30 : : *
31 : : * Exclusion constraints are different from unique indexes in that when the
32 : : * tuple is inserted to the index, the index AM does not check for
33 : : * duplicate keys at the same time. After the insertion, we perform a
34 : : * separate scan on the index to check for conflicting tuples, and if one
35 : : * is found, we throw an error and the transaction is aborted. If the
36 : : * conflicting tuple's inserter or deleter is in-progress, we wait for it
37 : : * to finish first.
38 : : *
39 : : * There is a chance of deadlock, if two backends insert a tuple at the
40 : : * same time, and then perform the scan to check for conflicts. They will
41 : : * find each other's tuple, and both try to wait for each other. The
42 : : * deadlock detector will detect that, and abort one of the transactions.
43 : : * That's fairly harmless, as one of them was bound to abort with a
44 : : * "duplicate key error" anyway, although you get a different error
45 : : * message.
46 : : *
47 : : * If an exclusion constraint is deferred, we still perform the conflict
48 : : * checking scan immediately after inserting the index tuple. But instead
49 : : * of throwing an error if a conflict is found, we return that information
50 : : * to the caller. The caller must re-check them later by calling
51 : : * check_exclusion_constraint().
52 : : *
53 : : * Speculative insertion
54 : : * ---------------------
55 : : *
56 : : * Speculative insertion is a two-phase mechanism used to implement
57 : : * INSERT ... ON CONFLICT. The tuple is first inserted into the heap
58 : : * and the indexes are updated as usual, but if a constraint is violated,
59 : : * we can still back out of the insertion without aborting the whole
60 : : * transaction. In an INSERT ... ON CONFLICT statement, if a conflict is
61 : : * detected, the inserted tuple is backed out and the ON CONFLICT action is
62 : : * executed instead.
63 : : *
64 : : * Insertion to a unique index works as usual: the index AM checks for
65 : : * duplicate keys atomically with the insertion. But instead of throwing
66 : : * an error on a conflict, the speculatively inserted heap tuple is backed
67 : : * out.
68 : : *
69 : : * Exclusion constraints are slightly more complicated. As mentioned
70 : : * earlier, there is a risk of deadlock when two backends insert the same
71 : : * key concurrently. That was not a problem for regular insertions, when
72 : : * one of the transactions has to be aborted anyway, but with a speculative
73 : : * insertion we cannot let a deadlock happen, because we only want to back
74 : : * out the speculatively inserted tuple on conflict, not abort the whole
75 : : * transaction.
76 : : *
77 : : * When a backend detects that the speculative insertion conflicts with
78 : : * another in-progress tuple, it has two options:
79 : : *
80 : : * 1. back out the speculatively inserted tuple, then wait for the other
81 : : * transaction, and retry. Or,
82 : : * 2. wait for the other transaction, with the speculatively inserted tuple
83 : : * still in place.
84 : : *
85 : : * If two backends insert at the same time, and both try to wait for each
86 : : * other, they will deadlock. So option 2 is not acceptable. Option 1
87 : : * avoids the deadlock, but it is prone to a livelock instead. Both
88 : : * transactions will wake up immediately as the other transaction backs
89 : : * out. Then they both retry, and conflict with each other again, lather,
90 : : * rinse, repeat.
91 : : *
92 : : * To avoid the livelock, one of the backends must back out first, and then
93 : : * wait, while the other one waits without backing out. It doesn't matter
94 : : * which one backs out, so we employ an arbitrary rule that the transaction
95 : : * with the higher XID backs out.
96 : : *
97 : : *
98 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
99 : : * Portions Copyright (c) 1994, Regents of the University of California
100 : : *
101 : : *
102 : : * IDENTIFICATION
103 : : * src/backend/executor/execIndexing.c
104 : : *
105 : : *-------------------------------------------------------------------------
106 : : */
107 : : #include "postgres.h"
108 : :
109 : : #include "access/genam.h"
110 : : #include "access/relscan.h"
111 : : #include "access/tableam.h"
112 : : #include "access/xact.h"
113 : : #include "catalog/index.h"
114 : : #include "executor/executor.h"
115 : : #include "nodes/nodeFuncs.h"
116 : : #include "storage/lmgr.h"
117 : : #include "utils/injection_point.h"
118 : : #include "utils/multirangetypes.h"
119 : : #include "utils/rangetypes.h"
120 : : #include "utils/snapmgr.h"
121 : :
122 : : /* waitMode argument to check_exclusion_or_unique_constraint() */
123 : : typedef enum
124 : : {
125 : : CEOUC_WAIT,
126 : : CEOUC_NOWAIT,
127 : : CEOUC_LIVELOCK_PREVENTING_WAIT,
128 : : } CEOUC_WAIT_MODE;
129 : :
130 : : static bool check_exclusion_or_unique_constraint(Relation heap, Relation index,
131 : : IndexInfo *indexInfo,
132 : : const ItemPointerData *tupleid,
133 : : const Datum *values, const bool *isnull,
134 : : EState *estate, bool newIndex,
135 : : CEOUC_WAIT_MODE waitMode,
136 : : bool violationOK,
137 : : ItemPointer conflictTid);
138 : :
139 : : static bool index_recheck_constraint(Relation index, const Oid *constr_procs,
140 : : const Datum *existing_values, const bool *existing_isnull,
141 : : const Datum *new_values);
142 : : static bool index_unchanged_by_update(ResultRelInfo *resultRelInfo,
143 : : EState *estate, IndexInfo *indexInfo,
144 : : Relation indexRelation);
145 : : static bool index_expression_changed_walker(Node *node,
146 : : Bitmapset *allUpdatedCols);
147 : : static void ExecWithoutOverlapsNotEmpty(Relation rel, NameData attname, Datum attval,
148 : : char typtype, Oid atttypid);
149 : :
150 : : /* ----------------------------------------------------------------
151 : : * ExecOpenIndices
152 : : *
153 : : * Find the indices associated with a result relation, open them,
154 : : * and save information about them in the result ResultRelInfo.
155 : : *
156 : : * At entry, caller has already opened and locked
157 : : * resultRelInfo->ri_RelationDesc.
158 : : * ----------------------------------------------------------------
159 : : */
160 : : void
3964 andres@anarazel.de 161 :CBC 995674 : ExecOpenIndices(ResultRelInfo *resultRelInfo, bool speculative)
162 : : {
3978 heikki.linnakangas@i 163 : 995674 : Relation resultRelation = resultRelInfo->ri_RelationDesc;
164 : : List *indexoidlist;
165 : : ListCell *l;
166 : : int len,
167 : : i;
168 : : RelationPtr relationDescs;
169 : : IndexInfo **indexInfoArray;
170 : :
171 : 995674 : resultRelInfo->ri_NumIndices = 0;
172 : :
173 : : /* fast path if no indexes */
174 [ + + ]: 995674 : if (!RelationGetForm(resultRelation)->relhasindex)
175 : 41388 : return;
176 : :
177 : : /*
178 : : * Get cached list of index OIDs
179 : : */
180 : 954286 : indexoidlist = RelationGetIndexList(resultRelation);
181 : 954286 : len = list_length(indexoidlist);
182 [ + + ]: 954286 : if (len == 0)
183 : 20296 : return;
184 : :
185 : : /* This Assert will fail if ExecOpenIndices is called twice */
389 tgl@sss.pgh.pa.us 186 [ - + ]: 933990 : Assert(resultRelInfo->ri_IndexRelationDescs == NULL);
187 : :
188 : : /*
189 : : * allocate space for result arrays
190 : : */
95 michael@paquier.xyz 191 :GNC 933990 : relationDescs = palloc_array(Relation, len);
192 : 933990 : indexInfoArray = palloc_array(IndexInfo *, len);
193 : :
3978 heikki.linnakangas@i 194 :CBC 933990 : resultRelInfo->ri_NumIndices = len;
195 : 933990 : resultRelInfo->ri_IndexRelationDescs = relationDescs;
196 : 933990 : resultRelInfo->ri_IndexRelationInfo = indexInfoArray;
197 : :
198 : : /*
199 : : * For each index, open the index relation and save pg_index info. We
200 : : * acquire RowExclusiveLock, signifying we will update the index.
201 : : *
202 : : * Note: we do this even if the index is not indisready; it's not worth
203 : : * the trouble to optimize for the case where it isn't.
204 : : */
205 : 933990 : i = 0;
206 [ + - + + : 2812864 : foreach(l, indexoidlist)
+ + ]
207 : : {
208 : 1878874 : Oid indexOid = lfirst_oid(l);
209 : : Relation indexDesc;
210 : : IndexInfo *ii;
211 : :
212 : 1878874 : indexDesc = index_open(indexOid, RowExclusiveLock);
213 : :
214 : : /* extract index key information from the index's pg_index info */
215 : 1878874 : ii = BuildIndexInfo(indexDesc);
216 : :
217 : : /*
218 : : * If the indexes are to be used for speculative insertion, add extra
219 : : * information required by unique index entries.
220 : : */
544 peter@eisentraut.org 221 [ + + + + : 1878874 : if (speculative && ii->ii_Unique && !indexDesc->rd_index->indisexclusion)
+ + ]
3964 andres@anarazel.de 222 : 863 : BuildSpeculativeIndexInfo(indexDesc, ii);
223 : :
3978 heikki.linnakangas@i 224 : 1878874 : relationDescs[i] = indexDesc;
225 : 1878874 : indexInfoArray[i] = ii;
226 : 1878874 : i++;
227 : : }
228 : :
229 : 933990 : list_free(indexoidlist);
230 : : }
231 : :
232 : : /* ----------------------------------------------------------------
233 : : * ExecCloseIndices
234 : : *
235 : : * Close the index relations stored in resultRelInfo
236 : : * ----------------------------------------------------------------
237 : : */
238 : : void
239 : 1035210 : ExecCloseIndices(ResultRelInfo *resultRelInfo)
240 : : {
241 : : int i;
242 : : int numIndices;
243 : : RelationPtr indexDescs;
244 : : IndexInfo **indexInfos;
245 : :
246 : 1035210 : numIndices = resultRelInfo->ri_NumIndices;
247 : 1035210 : indexDescs = resultRelInfo->ri_IndexRelationDescs;
841 tomas.vondra@postgre 248 : 1035210 : indexInfos = resultRelInfo->ri_IndexRelationInfo;
249 : :
3978 heikki.linnakangas@i 250 [ + + ]: 2913023 : for (i = 0; i < numIndices; i++)
251 : : {
252 : : /* This Assert will fail if ExecCloseIndices is called twice */
389 tgl@sss.pgh.pa.us 253 [ - + ]: 1877813 : Assert(indexDescs[i] != NULL);
254 : :
255 : : /* Give the index a chance to do some post-insert cleanup */
841 tomas.vondra@postgre 256 : 1877813 : index_insert_cleanup(indexDescs[i], indexInfos[i]);
257 : :
258 : : /* Drop lock acquired by ExecOpenIndices */
3978 heikki.linnakangas@i 259 : 1877813 : index_close(indexDescs[i], RowExclusiveLock);
260 : :
261 : : /* Mark the index as closed */
389 tgl@sss.pgh.pa.us 262 : 1877813 : indexDescs[i] = NULL;
263 : : }
264 : :
265 : : /*
266 : : * We don't attempt to free the IndexInfo data structures or the arrays,
267 : : * instead assuming that such stuff will be cleaned up automatically in
268 : : * FreeExecutorState.
269 : : */
3978 heikki.linnakangas@i 270 : 1035210 : }
271 : :
272 : : /* ----------------------------------------------------------------
273 : : * ExecInsertIndexTuples
274 : : *
275 : : * This routine takes care of inserting index tuples
276 : : * into all the relations indexing the result relation
277 : : * when a heap tuple is inserted into the result relation.
278 : : *
279 : : * When EIIT_IS_UPDATE is set and EIIT_ONLY_SUMMARIZING isn't,
280 : : * executor is performing an UPDATE that could not use an
281 : : * optimization like heapam's HOT (in more general terms a
282 : : * call to table_tuple_update() took place and set
283 : : * 'update_indexes' to TU_All). Receiving this hint makes
284 : : * us consider if we should pass down the 'indexUnchanged'
285 : : * hint in turn. That's something that we figure out for
286 : : * each index_insert() call iff EIIT_IS_UPDATE is set.
287 : : * (When that flag is not set we already know not to pass the
288 : : * hint to any index.)
289 : : *
290 : : * If EIIT_ONLY_SUMMARIZING is set, an equivalent optimization to
291 : : * HOT has been applied and any updated columns are indexed
292 : : * only by summarizing indexes (or in more general terms a
293 : : * call to table_tuple_update() took place and set
294 : : * 'update_indexes' to TU_Summarizing). We can (and must)
295 : : * therefore only update the indexes that have
296 : : * 'amsummarizing' = true.
297 : : *
298 : : * Unique and exclusion constraints are enforced at the same
299 : : * time. This returns a list of index OIDs for any unique or
300 : : * exclusion constraints that are deferred and that had
301 : : * potential (unconfirmed) conflicts. (if EIIT_NO_DUPE_ERROR,
302 : : * the same is done for non-deferred constraints, but report
303 : : * if conflict was speculative or deferred conflict to caller)
304 : : *
305 : : * If 'arbiterIndexes' is nonempty, EIIT_NO_DUPE_ERROR applies only to
306 : : * those indexes. NIL means EIIT_NO_DUPE_ERROR applies to all indexes.
307 : : * ----------------------------------------------------------------
308 : : */
309 : : List *
1978 310 : 2287992 : ExecInsertIndexTuples(ResultRelInfo *resultRelInfo,
311 : : EState *estate,
312 : : bits32 flags,
313 : : TupleTableSlot *slot,
314 : : List *arbiterIndexes,
315 : : bool *specConflict)
316 : : {
2549 andres@anarazel.de 317 : 2287992 : ItemPointer tupleid = &slot->tts_tid;
3978 heikki.linnakangas@i 318 : 2287992 : List *result = NIL;
319 : : int i;
320 : : int numIndices;
321 : : RelationPtr relationDescs;
322 : : Relation heapRelation;
323 : : IndexInfo **indexInfoArray;
324 : : ExprContext *econtext;
325 : : Datum values[INDEX_MAX_KEYS];
326 : : bool isnull[INDEX_MAX_KEYS];
327 : :
2549 andres@anarazel.de 328 [ - + ]: 2287992 : Assert(ItemPointerIsValid(tupleid));
329 : :
330 : : /*
331 : : * Get information from the result relation info structure.
332 : : */
3978 heikki.linnakangas@i 333 : 2287992 : numIndices = resultRelInfo->ri_NumIndices;
334 : 2287992 : relationDescs = resultRelInfo->ri_IndexRelationDescs;
335 : 2287992 : indexInfoArray = resultRelInfo->ri_IndexRelationInfo;
336 : 2287992 : heapRelation = resultRelInfo->ri_RelationDesc;
337 : :
338 : : /* Sanity check: slot must belong to the same rel as the resultRelInfo. */
2475 drowley@postgresql.o 339 [ - + ]: 2287992 : Assert(slot->tts_tableOid == RelationGetRelid(heapRelation));
340 : :
341 : : /*
342 : : * We will use the EState's per-tuple context for evaluating predicates
343 : : * and index expressions (creating it if it's not already there).
344 : : */
3978 heikki.linnakangas@i 345 [ + + ]: 2287992 : econtext = GetPerTupleExprContext(estate);
346 : :
347 : : /* Arrange for econtext's scan tuple to be the tuple under test */
348 : 2287992 : econtext->ecxt_scantuple = slot;
349 : :
350 : : /*
351 : : * for each index, form and insert the index tuple
352 : : */
353 [ + + ]: 4760871 : for (i = 0; i < numIndices; i++)
354 : : {
355 : 2473239 : Relation indexRelation = relationDescs[i];
356 : : IndexInfo *indexInfo;
357 : : bool applyNoDupErr;
358 : : IndexUniqueCheck checkUnique;
359 : : bool indexUnchanged;
360 : : bool satisfiesConstraint;
361 : :
362 [ - + ]: 2473239 : if (indexRelation == NULL)
3978 heikki.linnakangas@i 363 :UBC 0 : continue;
364 : :
3978 heikki.linnakangas@i 365 :CBC 2473239 : indexInfo = indexInfoArray[i];
366 : :
367 : : /* If the index is marked as read-only, ignore it */
368 [ + + ]: 2473239 : if (!indexInfo->ii_ReadyForInserts)
369 : 99 : continue;
370 : :
371 : : /*
372 : : * Skip processing of non-summarizing indexes if we only update
373 : : * summarizing indexes
374 : : */
26 alvherre@kurilemu.de 375 [ + + + + ]:GNC 2473140 : if ((flags & EIIT_ONLY_SUMMARIZING) && !indexInfo->ii_Summarizing)
1091 tomas.vondra@postgre 376 :CBC 3 : continue;
377 : :
378 : : /* Check for partial index */
3978 heikki.linnakangas@i 379 [ + + ]: 2473137 : if (indexInfo->ii_Predicate != NIL)
380 : : {
381 : : ExprState *predicate;
382 : :
383 : : /*
384 : : * If predicate state not set up yet, create it (in the estate's
385 : : * per-query context)
386 : : */
387 : 200551 : predicate = indexInfo->ii_PredicateState;
3288 andres@anarazel.de 388 [ + + ]: 200551 : if (predicate == NULL)
389 : : {
390 : 136 : predicate = ExecPrepareQual(indexInfo->ii_Predicate, estate);
3978 heikki.linnakangas@i 391 : 136 : indexInfo->ii_PredicateState = predicate;
392 : : }
393 : :
394 : : /* Skip this index-update if the predicate isn't satisfied */
3288 andres@anarazel.de 395 [ + + ]: 200551 : if (!ExecQual(predicate, econtext))
3978 heikki.linnakangas@i 396 : 200280 : continue;
397 : : }
398 : :
399 : : /*
400 : : * FormIndexDatum fills in its values and isnull parameters with the
401 : : * appropriate values for the column(s) of the index.
402 : : */
403 : 2272857 : FormIndexDatum(indexInfo,
404 : : slot,
405 : : estate,
406 : : values,
407 : : isnull);
408 : :
409 : : /* Check whether to apply noDupErr to this index */
26 alvherre@kurilemu.de 410 [ + + + + ]:GNC 2350823 : applyNoDupErr = (flags & EIIT_NO_DUPE_ERROR) &&
3541 tgl@sss.pgh.pa.us 411 [ + + ]:CBC 77966 : (arbiterIndexes == NIL ||
412 : 77966 : list_member_oid(arbiterIndexes,
413 : 77966 : indexRelation->rd_index->indexrelid));
414 : :
415 : : /*
416 : : * The index AM does the actual insertion, plus uniqueness checking.
417 : : *
418 : : * For an immediate-mode unique index, we just tell the index AM to
419 : : * throw error if not unique.
420 : : *
421 : : * For a deferrable unique index, we tell the index AM to just detect
422 : : * possible non-uniqueness, and we add the index OID to the result
423 : : * list if further checking is needed.
424 : : *
425 : : * For a speculative insertion (used by INSERT ... ON CONFLICT), do
426 : : * the same as for a deferrable unique index.
427 : : */
3978 heikki.linnakangas@i 428 [ + + ]: 2272857 : if (!indexRelation->rd_index->indisunique)
429 : 1107633 : checkUnique = UNIQUE_CHECK_NO;
3541 tgl@sss.pgh.pa.us 430 [ + + ]: 1165224 : else if (applyNoDupErr)
3964 andres@anarazel.de 431 : 78004 : checkUnique = UNIQUE_CHECK_PARTIAL;
3978 heikki.linnakangas@i 432 [ + + ]: 1087220 : else if (indexRelation->rd_index->indimmediate)
433 : 1087145 : checkUnique = UNIQUE_CHECK_YES;
434 : : else
435 : 75 : checkUnique = UNIQUE_CHECK_PARTIAL;
436 : :
437 : : /*
438 : : * There's definitely going to be an index_insert() call for this
439 : : * index. If we're being called as part of an UPDATE statement,
440 : : * consider if the 'indexUnchanged' = true hint should be passed.
441 : : */
26 alvherre@kurilemu.de 442 [ + + + + ]:GNC 2451391 : indexUnchanged = ((flags & EIIT_IS_UPDATE) &&
443 : 178534 : index_unchanged_by_update(resultRelInfo,
444 : : estate,
445 : : indexInfo,
446 : : indexRelation));
447 : :
448 : : satisfiesConstraint =
3978 heikki.linnakangas@i 449 :CBC 2272857 : index_insert(indexRelation, /* index relation */
450 : : values, /* array of index Datums */
451 : : isnull, /* null flags */
452 : : tupleid, /* tid of heap tuple */
453 : : heapRelation, /* heap relation */
454 : : checkUnique, /* type of uniqueness check to do */
455 : : indexUnchanged, /* UPDATE without logical change? */
456 : : indexInfo); /* index AM may need this */
457 : :
458 : : /*
459 : : * If the index has an associated exclusion constraint, check that.
460 : : * This is simpler than the process for uniqueness checks since we
461 : : * always insert first and then check. If the constraint is deferred,
462 : : * we check now anyway, but don't throw error on violation or wait for
463 : : * a conclusive outcome from a concurrent insertion; instead we'll
464 : : * queue a recheck event. Similarly, noDupErr callers (speculative
465 : : * inserters) will recheck later, and wait for a conclusive outcome
466 : : * then.
467 : : *
468 : : * An index for an exclusion constraint can't also be UNIQUE (not an
469 : : * essential property, we just don't allow it in the grammar), so no
470 : : * need to preserve the prior state of satisfiesConstraint.
471 : : */
472 [ + + ]: 2272584 : if (indexInfo->ii_ExclusionOps != NULL)
473 : : {
474 : : bool violationOK;
475 : : CEOUC_WAIT_MODE waitMode;
476 : :
3541 tgl@sss.pgh.pa.us 477 [ + + ]: 997 : if (applyNoDupErr)
478 : : {
3964 andres@anarazel.de 479 : 72 : violationOK = true;
480 : 72 : waitMode = CEOUC_LIVELOCK_PREVENTING_WAIT;
481 : : }
482 [ + + ]: 925 : else if (!indexRelation->rd_index->indimmediate)
483 : : {
484 : 21 : violationOK = true;
485 : 21 : waitMode = CEOUC_NOWAIT;
486 : : }
487 : : else
488 : : {
489 : 904 : violationOK = false;
490 : 904 : waitMode = CEOUC_WAIT;
491 : : }
492 : :
493 : : satisfiesConstraint =
494 : 997 : check_exclusion_or_unique_constraint(heapRelation,
495 : : indexRelation, indexInfo,
496 : : tupleid, values, isnull,
497 : : estate, false,
498 : : waitMode, violationOK, NULL);
499 : : }
500 : :
3978 heikki.linnakangas@i 501 [ + + ]: 2272497 : if ((checkUnique == UNIQUE_CHECK_PARTIAL ||
502 [ + + ]: 2194418 : indexInfo->ii_ExclusionOps != NULL) &&
503 [ + + ]: 78917 : !satisfiesConstraint)
504 : : {
505 : : /*
506 : : * The tuple potentially violates the uniqueness or exclusion
507 : : * constraint, so make a note of the index so that we can re-check
508 : : * it later. Speculative inserters are told if there was a
509 : : * speculative conflict, since that always requires a restart.
510 : : */
511 : 140 : result = lappend_oid(result, RelationGetRelid(indexRelation));
3964 andres@anarazel.de 512 [ + + + - ]: 140 : if (indexRelation->rd_index->indimmediate && specConflict)
513 : 79 : *specConflict = true;
514 : : }
515 : : }
516 : :
3978 heikki.linnakangas@i 517 : 2287632 : return result;
518 : : }
519 : :
520 : : /* ----------------------------------------------------------------
521 : : * ExecCheckIndexConstraints
522 : : *
523 : : * This routine checks if a tuple violates any unique or
524 : : * exclusion constraints. Returns true if there is no conflict.
525 : : * Otherwise returns false, and the TID of the conflicting
526 : : * tuple is returned in *conflictTid.
527 : : *
528 : : * If 'arbiterIndexes' is given, only those indexes are checked.
529 : : * NIL means all indexes.
530 : : *
531 : : * Note that this doesn't lock the values in any way, so it's
532 : : * possible that a conflicting tuple is inserted immediately
533 : : * after this returns. This can be used for either a pre-check
534 : : * before insertion or a re-check after finding a conflict.
535 : : *
536 : : * 'tupleid' should be the TID of the tuple that has been recently
537 : : * inserted (or can be invalid if we haven't inserted a new tuple yet).
538 : : * This tuple will be excluded from conflict checking.
539 : : * ----------------------------------------------------------------
540 : : */
541 : : bool
1978 542 : 5082 : ExecCheckIndexConstraints(ResultRelInfo *resultRelInfo, TupleTableSlot *slot,
543 : : EState *estate, ItemPointer conflictTid,
544 : : const ItemPointerData *tupleid, List *arbiterIndexes)
545 : : {
546 : : int i;
547 : : int numIndices;
548 : : RelationPtr relationDescs;
549 : : Relation heapRelation;
550 : : IndexInfo **indexInfoArray;
551 : : ExprContext *econtext;
552 : : Datum values[INDEX_MAX_KEYS];
553 : : bool isnull[INDEX_MAX_KEYS];
554 : : ItemPointerData invalidItemPtr;
3964 andres@anarazel.de 555 : 5082 : bool checkedIndex = false;
556 : :
557 : 5082 : ItemPointerSetInvalid(conflictTid);
558 : 5082 : ItemPointerSetInvalid(&invalidItemPtr);
559 : :
560 : : /*
561 : : * Get information from the result relation info structure.
562 : : */
563 : 5082 : numIndices = resultRelInfo->ri_NumIndices;
564 : 5082 : relationDescs = resultRelInfo->ri_IndexRelationDescs;
565 : 5082 : indexInfoArray = resultRelInfo->ri_IndexRelationInfo;
566 : 5082 : heapRelation = resultRelInfo->ri_RelationDesc;
567 : :
568 : : /*
569 : : * We will use the EState's per-tuple context for evaluating predicates
570 : : * and index expressions (creating it if it's not already there).
571 : : */
572 [ + + ]: 5082 : econtext = GetPerTupleExprContext(estate);
573 : :
574 : : /* Arrange for econtext's scan tuple to be the tuple under test */
575 : 5082 : econtext->ecxt_scantuple = slot;
576 : :
577 : : /*
578 : : * For each index, form index tuple and check if it satisfies the
579 : : * constraint.
580 : : */
581 [ + + ]: 7312 : for (i = 0; i < numIndices; i++)
582 : : {
583 : 5179 : Relation indexRelation = relationDescs[i];
584 : : IndexInfo *indexInfo;
585 : : bool satisfiesConstraint;
586 : :
587 [ - + ]: 5179 : if (indexRelation == NULL)
3964 andres@anarazel.de 588 :UBC 0 : continue;
589 : :
3964 andres@anarazel.de 590 :CBC 5179 : indexInfo = indexInfoArray[i];
591 : :
592 [ + + + + ]: 5179 : if (!indexInfo->ii_Unique && !indexInfo->ii_ExclusionOps)
593 : 2 : continue;
594 : :
595 : : /* If the index is marked as read-only, ignore it */
596 [ - + ]: 5177 : if (!indexInfo->ii_ReadyForInserts)
3964 andres@anarazel.de 597 :UBC 0 : continue;
598 : :
599 : : /* When specific arbiter indexes requested, only examine them */
3964 andres@anarazel.de 600 [ + + ]:CBC 5177 : if (arbiterIndexes != NIL &&
601 [ + + ]: 5042 : !list_member_oid(arbiterIndexes,
602 : 5042 : indexRelation->rd_index->indexrelid))
603 : 70 : continue;
604 : :
605 [ + + ]: 5107 : if (!indexRelation->rd_index->indimmediate)
606 [ + - ]: 3 : ereport(ERROR,
607 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
608 : : errmsg("ON CONFLICT does not support deferrable unique constraints/exclusion constraints as arbiters"),
609 : : errtableconstraint(heapRelation,
610 : : RelationGetRelationName(indexRelation))));
611 : :
612 : 5104 : checkedIndex = true;
613 : :
614 : : /* Check for partial index */
615 [ + + ]: 5104 : if (indexInfo->ii_Predicate != NIL)
616 : : {
617 : : ExprState *predicate;
618 : :
619 : : /*
620 : : * If predicate state not set up yet, create it (in the estate's
621 : : * per-query context)
622 : : */
623 : 20 : predicate = indexInfo->ii_PredicateState;
3288 624 [ + - ]: 20 : if (predicate == NULL)
625 : : {
626 : 20 : predicate = ExecPrepareQual(indexInfo->ii_Predicate, estate);
3964 627 : 20 : indexInfo->ii_PredicateState = predicate;
628 : : }
629 : :
630 : : /* Skip this index-update if the predicate isn't satisfied */
3288 631 [ - + ]: 20 : if (!ExecQual(predicate, econtext))
3964 andres@anarazel.de 632 :UBC 0 : continue;
633 : : }
634 : :
635 : : /*
636 : : * FormIndexDatum fills in its values and isnull parameters with the
637 : : * appropriate values for the column(s) of the index.
638 : : */
3964 andres@anarazel.de 639 :CBC 5104 : FormIndexDatum(indexInfo,
640 : : slot,
641 : : estate,
642 : : values,
643 : : isnull);
644 : :
645 : : satisfiesConstraint =
646 : 5104 : check_exclusion_or_unique_constraint(heapRelation, indexRelation,
647 : : indexInfo, tupleid,
648 : : values, isnull, estate, false,
649 : : CEOUC_WAIT, true,
650 : : conflictTid);
651 [ + + ]: 5103 : if (!satisfiesConstraint)
652 : 2945 : return false;
653 : : }
654 : :
655 [ + + - + ]: 2133 : if (arbiterIndexes != NIL && !checkedIndex)
3964 andres@anarazel.de 656 [ # # ]:UBC 0 : elog(ERROR, "unexpected failure to find arbiter index");
657 : :
3964 andres@anarazel.de 658 :CBC 2133 : return true;
659 : : }
660 : :
661 : : /*
662 : : * Check for violation of an exclusion or unique constraint
663 : : *
664 : : * heap: the table containing the new tuple
665 : : * index: the index supporting the constraint
666 : : * indexInfo: info about the index, including the exclusion properties
667 : : * tupleid: heap TID of the new tuple we have just inserted (invalid if we
668 : : * haven't inserted a new tuple yet)
669 : : * values, isnull: the *index* column values computed for the new tuple
670 : : * estate: an EState we can do evaluation in
671 : : * newIndex: if true, we are trying to build a new index (this affects
672 : : * only the wording of error messages)
673 : : * waitMode: whether to wait for concurrent inserters/deleters
674 : : * violationOK: if true, don't throw error for violation
675 : : * conflictTid: if not-NULL, the TID of the conflicting tuple is returned here
676 : : *
677 : : * Returns true if OK, false if actual or potential violation
678 : : *
679 : : * 'waitMode' determines what happens if a conflict is detected with a tuple
680 : : * that was inserted or deleted by a transaction that's still running.
681 : : * CEOUC_WAIT means that we wait for the transaction to commit, before
682 : : * throwing an error or returning. CEOUC_NOWAIT means that we report the
683 : : * violation immediately; so the violation is only potential, and the caller
684 : : * must recheck sometime later. This behavior is convenient for deferred
685 : : * exclusion checks; we need not bother queuing a deferred event if there is
686 : : * definitely no conflict at insertion time.
687 : : *
688 : : * CEOUC_LIVELOCK_PREVENTING_WAIT is like CEOUC_NOWAIT, but we will sometimes
689 : : * wait anyway, to prevent livelocking if two transactions try inserting at
690 : : * the same time. This is used with speculative insertions, for INSERT ON
691 : : * CONFLICT statements. (See notes in file header)
692 : : *
693 : : * If violationOK is true, we just report the potential or actual violation to
694 : : * the caller by returning 'false'. Otherwise we throw a descriptive error
695 : : * message here. When violationOK is false, a false result is impossible.
696 : : *
697 : : * Note: The indexam is normally responsible for checking unique constraints,
698 : : * so this normally only needs to be used for exclusion constraints. But this
699 : : * function is also called when doing a "pre-check" for conflicts on a unique
700 : : * constraint, when doing speculative insertion. Caller may use the returned
701 : : * conflict TID to take further steps.
702 : : */
703 : : static bool
704 : 6340 : check_exclusion_or_unique_constraint(Relation heap, Relation index,
705 : : IndexInfo *indexInfo,
706 : : const ItemPointerData *tupleid,
707 : : const Datum *values, const bool *isnull,
708 : : EState *estate, bool newIndex,
709 : : CEOUC_WAIT_MODE waitMode,
710 : : bool violationOK,
711 : : ItemPointer conflictTid)
712 : : {
713 : : Oid *constr_procs;
714 : : uint16 *constr_strats;
3978 heikki.linnakangas@i 715 : 6340 : Oid *index_collations = index->rd_indcollation;
2899 teodor@sigaev.ru 716 : 6340 : int indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
717 : : IndexScanDesc index_scan;
718 : : ScanKeyData scankeys[INDEX_MAX_KEYS];
719 : : SnapshotData DirtySnapshot;
720 : : int i;
721 : : bool conflict;
722 : : bool found_self;
723 : : ExprContext *econtext;
724 : : TupleTableSlot *existing_slot;
725 : : TupleTableSlot *save_scantuple;
726 : :
3964 andres@anarazel.de 727 [ + + ]: 6340 : if (indexInfo->ii_ExclusionOps)
728 : : {
729 : 1314 : constr_procs = indexInfo->ii_ExclusionProcs;
730 : 1314 : constr_strats = indexInfo->ii_ExclusionStrats;
731 : : }
732 : : else
733 : : {
734 : 5026 : constr_procs = indexInfo->ii_UniqueProcs;
735 : 5026 : constr_strats = indexInfo->ii_UniqueStrats;
736 : : }
737 : :
738 : : /*
739 : : * If this is a WITHOUT OVERLAPS constraint, we must also forbid empty
740 : : * ranges/multiranges. This must happen before we look for NULLs below, or
741 : : * a UNIQUE constraint could insert an empty range along with a NULL
742 : : * scalar part.
743 : : */
544 peter@eisentraut.org 744 [ + + ]: 6340 : if (indexInfo->ii_WithoutOverlaps)
745 : : {
746 : : /*
747 : : * Look up the type from the heap tuple, but check the Datum from the
748 : : * index tuple.
749 : : */
750 : 1111 : AttrNumber attno = indexInfo->ii_IndexAttrNumbers[indnkeyatts - 1];
751 : :
752 [ + + ]: 1111 : if (!isnull[indnkeyatts - 1])
753 : : {
754 : 1081 : TupleDesc tupdesc = RelationGetDescr(heap);
755 : 1081 : Form_pg_attribute att = TupleDescAttr(tupdesc, attno - 1);
756 : 1081 : TypeCacheEntry *typcache = lookup_type_cache(att->atttypid, 0);
757 : :
758 : 1081 : ExecWithoutOverlapsNotEmpty(heap, att->attname,
759 : 1081 : values[indnkeyatts - 1],
760 : 1081 : typcache->typtype, att->atttypid);
761 : : }
762 : : }
763 : :
764 : : /*
765 : : * If any of the input values are NULL, and the index uses the default
766 : : * nulls-are-distinct mode, the constraint check is assumed to pass (i.e.,
767 : : * we assume the operators are strict). Otherwise, we interpret the
768 : : * constraint as specifying IS NULL for each column whose input value is
769 : : * NULL.
770 : : */
1319 tgl@sss.pgh.pa.us 771 [ + + ]: 6298 : if (!indexInfo->ii_NullsNotDistinct)
772 : : {
773 [ + + ]: 13688 : for (i = 0; i < indnkeyatts; i++)
774 : : {
775 [ + + ]: 7453 : if (isnull[i])
776 : 60 : return true;
777 : : }
778 : : }
779 : :
780 : : /*
781 : : * Search the tuples that are in the index for any violations, including
782 : : * tuples that aren't visible yet.
783 : : */
3978 heikki.linnakangas@i 784 : 6238 : InitDirtySnapshot(DirtySnapshot);
785 : :
2899 teodor@sigaev.ru 786 [ + + ]: 13604 : for (i = 0; i < indnkeyatts; i++)
787 : : {
3978 heikki.linnakangas@i 788 : 7366 : ScanKeyEntryInitialize(&scankeys[i],
1319 tgl@sss.pgh.pa.us 789 : 7366 : isnull[i] ? SK_ISNULL | SK_SEARCHNULL : 0,
3978 heikki.linnakangas@i 790 : 7366 : i + 1,
791 : 7366 : constr_strats[i],
792 : : InvalidOid,
793 : 7366 : index_collations[i],
794 : 7366 : constr_procs[i],
795 [ + + ]: 7366 : values[i]);
796 : : }
797 : :
798 : : /*
799 : : * Need a TupleTableSlot to put existing tuples in.
800 : : *
801 : : * To use FormIndexDatum, we have to make the econtext's scantuple point
802 : : * to this slot. Be sure to save and restore caller's value for
803 : : * scantuple.
804 : : */
2561 andres@anarazel.de 805 : 6238 : existing_slot = table_slot_create(heap, NULL);
806 : :
3978 heikki.linnakangas@i 807 [ + - ]: 6238 : econtext = GetPerTupleExprContext(estate);
808 : 6238 : save_scantuple = econtext->ecxt_scantuple;
809 : 6238 : econtext->ecxt_scantuple = existing_slot;
810 : :
811 : : /*
812 : : * May have to restart scan from this point if a potential conflict is
813 : : * found.
814 : : */
815 : 6274 : retry:
816 : 6274 : conflict = false;
817 : 6274 : found_self = false;
369 pg@bowt.ie 818 : 6274 : index_scan = index_beginscan(heap, index, &DirtySnapshot, NULL, indnkeyatts, 0);
2899 teodor@sigaev.ru 819 : 6274 : index_rescan(index_scan, scankeys, indnkeyatts, NULL, 0);
820 : :
2561 andres@anarazel.de 821 [ + + ]: 7349 : while (index_getnext_slot(index_scan, ForwardScanDirection, existing_slot))
822 : : {
823 : : TransactionId xwait;
824 : : XLTW_Oper reason_wait;
825 : : Datum existing_values[INDEX_MAX_KEYS];
826 : : bool existing_isnull[INDEX_MAX_KEYS];
827 : : char *error_new;
828 : : char *error_existing;
829 : :
830 : : /*
831 : : * Ignore the entry for the tuple we're trying to check.
832 : : */
3964 833 [ + + + + ]: 5386 : if (ItemPointerIsValid(tupleid) &&
2561 834 : 1233 : ItemPointerEquals(tupleid, &existing_slot->tts_tid))
835 : : {
3978 heikki.linnakangas@i 836 [ - + ]: 1048 : if (found_self) /* should not happen */
3978 heikki.linnakangas@i 837 [ # # ]:UBC 0 : elog(ERROR, "found self tuple multiple times in index \"%s\"",
838 : : RelationGetRelationName(index));
3978 heikki.linnakangas@i 839 :CBC 1048 : found_self = true;
840 : 1075 : continue;
841 : : }
842 : :
843 : : /*
844 : : * Extract the index column values and isnull flags from the existing
845 : : * tuple.
846 : : */
847 : 3105 : FormIndexDatum(indexInfo, existing_slot, estate,
848 : : existing_values, existing_isnull);
849 : :
850 : : /* If lossy indexscan, must recheck the condition */
851 [ + + ]: 3105 : if (index_scan->xs_recheck)
852 : : {
853 [ + + ]: 69 : if (!index_recheck_constraint(index,
854 : : constr_procs,
855 : : existing_values,
856 : : existing_isnull,
857 : : values))
858 : 27 : continue; /* tuple doesn't actually match, so no
859 : : * conflict */
860 : : }
861 : :
862 : : /*
863 : : * At this point we have either a conflict or a potential conflict.
864 : : *
865 : : * If an in-progress transaction is affecting the visibility of this
866 : : * tuple, we need to wait for it to complete and then recheck (unless
867 : : * the caller requested not to). For simplicity we do rechecking by
868 : : * just restarting the whole scan --- this case probably doesn't
869 : : * happen often enough to be worth trying harder, and anyway we don't
870 : : * want to hold any index internal locks while waiting.
871 : : */
872 : 6156 : xwait = TransactionIdIsValid(DirtySnapshot.xmin) ?
873 [ + + ]: 3078 : DirtySnapshot.xmin : DirtySnapshot.xmax;
874 : :
3964 andres@anarazel.de 875 [ + + - + ]: 3078 : if (TransactionIdIsValid(xwait) &&
3964 andres@anarazel.de 876 [ # # ]:UBC 0 : (waitMode == CEOUC_WAIT ||
877 : 0 : (waitMode == CEOUC_LIVELOCK_PREVENTING_WAIT &&
878 [ # # # # ]: 0 : DirtySnapshot.speculativeToken &&
879 : 0 : TransactionIdPrecedes(GetCurrentTransactionId(), xwait))))
880 : : {
3652 sfrost@snowman.net 881 :CBC 74 : reason_wait = indexInfo->ii_ExclusionOps ?
882 [ - + ]: 37 : XLTW_RecheckExclusionConstr : XLTW_InsertIndex;
3978 heikki.linnakangas@i 883 : 37 : index_endscan(index_scan);
3964 andres@anarazel.de 884 [ + + ]: 37 : if (DirtySnapshot.speculativeToken)
885 : 1 : SpeculativeInsertionWait(DirtySnapshot.xmin,
886 : : DirtySnapshot.speculativeToken);
887 : : else
2561 888 : 36 : XactLockTableWait(xwait, heap,
2561 andres@anarazel.de 889 :GIC 36 : &existing_slot->tts_tid, reason_wait);
3978 heikki.linnakangas@i 890 :CBC 36 : goto retry;
891 : : }
892 : :
893 : : /*
894 : : * We have a definite conflict (or a potential one, but the caller
895 : : * didn't want to wait). Return it to caller, or report it.
896 : : */
3964 andres@anarazel.de 897 [ + + ]: 3041 : if (violationOK)
898 : : {
899 : 2957 : conflict = true;
900 [ + + ]: 2957 : if (conflictTid)
2561 901 : 2945 : *conflictTid = existing_slot->tts_tid;
3964 902 : 2957 : break;
903 : : }
904 : :
3978 heikki.linnakangas@i 905 : 84 : error_new = BuildIndexValueDescription(index, values, isnull);
906 : 84 : error_existing = BuildIndexValueDescription(index, existing_values,
907 : : existing_isnull);
908 [ + + ]: 84 : if (newIndex)
909 [ + - + - : 18 : ereport(ERROR,
+ - ]
910 : : (errcode(ERRCODE_EXCLUSION_VIOLATION),
911 : : errmsg("could not create exclusion constraint \"%s\"",
912 : : RelationGetRelationName(index)),
913 : : error_new && error_existing ?
914 : : errdetail("Key %s conflicts with key %s.",
915 : : error_new, error_existing) :
916 : : errdetail("Key conflicts exist."),
917 : : errtableconstraint(heap,
918 : : RelationGetRelationName(index))));
919 : : else
920 [ + - + - : 66 : ereport(ERROR,
+ - ]
921 : : (errcode(ERRCODE_EXCLUSION_VIOLATION),
922 : : errmsg("conflicting key value violates exclusion constraint \"%s\"",
923 : : RelationGetRelationName(index)),
924 : : error_new && error_existing ?
925 : : errdetail("Key %s conflicts with existing key %s.",
926 : : error_new, error_existing) :
927 : : errdetail("Key conflicts with existing key."),
928 : : errtableconstraint(heap,
929 : : RelationGetRelationName(index))));
930 : : }
931 : :
932 : 6153 : index_endscan(index_scan);
933 : :
934 : : /*
935 : : * Ordinarily, at this point the search should have found the originally
936 : : * inserted tuple (if any), unless we exited the loop early because of
937 : : * conflict. However, it is possible to define exclusion constraints for
938 : : * which that wouldn't be true --- for instance, if the operator is <>. So
939 : : * we no longer complain if found_self is still false.
940 : : */
941 : :
942 : 6153 : econtext->ecxt_scantuple = save_scantuple;
943 : :
944 : 6153 : ExecDropSingleTupleTableSlot(existing_slot);
945 : :
946 : : #ifdef USE_INJECTION_POINTS
110 alvherre@kurilemu.de 947 [ + + ]:GNC 6153 : if (!conflict)
111 948 : 3196 : INJECTION_POINT("check-exclusion-or-unique-constraint-no-conflict", NULL);
949 : : #endif
950 : :
3978 heikki.linnakangas@i 951 :CBC 6153 : return !conflict;
952 : : }
953 : :
954 : : /*
955 : : * Check for violation of an exclusion constraint
956 : : *
957 : : * This is a dumbed down version of check_exclusion_or_unique_constraint
958 : : * for external callers. They don't need all the special modes.
959 : : */
960 : : void
3964 andres@anarazel.de 961 : 239 : check_exclusion_constraint(Relation heap, Relation index,
962 : : IndexInfo *indexInfo,
963 : : const ItemPointerData *tupleid,
964 : : const Datum *values, const bool *isnull,
965 : : EState *estate, bool newIndex)
966 : : {
967 : 239 : (void) check_exclusion_or_unique_constraint(heap, index, indexInfo, tupleid,
968 : : values, isnull,
969 : : estate, newIndex,
970 : : CEOUC_WAIT, false, NULL);
971 : 200 : }
972 : :
973 : : /*
974 : : * Check existing tuple's index values to see if it really matches the
975 : : * exclusion condition against the new_values. Returns true if conflict.
976 : : */
977 : : static bool
887 peter@eisentraut.org 978 : 69 : index_recheck_constraint(Relation index, const Oid *constr_procs,
979 : : const Datum *existing_values, const bool *existing_isnull,
980 : : const Datum *new_values)
981 : : {
2899 teodor@sigaev.ru 982 : 69 : int indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
983 : : int i;
984 : :
985 [ + + ]: 171 : for (i = 0; i < indnkeyatts; i++)
986 : : {
987 : : /* Assume the exclusion operators are strict */
3978 heikki.linnakangas@i 988 [ - + ]: 129 : if (existing_isnull[i])
3978 heikki.linnakangas@i 989 :UBC 0 : return false;
990 : :
3978 heikki.linnakangas@i 991 [ + + ]:CBC 129 : if (!DatumGetBool(OidFunctionCall2Coll(constr_procs[i],
992 : 129 : index->rd_indcollation[i],
993 : 129 : existing_values[i],
994 : 129 : new_values[i])))
995 : 27 : return false;
996 : : }
997 : :
998 : 42 : return true;
999 : : }
1000 : :
1001 : : /*
1002 : : * Check if ExecInsertIndexTuples() should pass indexUnchanged hint.
1003 : : *
1004 : : * When the executor performs an UPDATE that requires a new round of index
1005 : : * tuples, determine if we should pass 'indexUnchanged' = true hint for one
1006 : : * single index.
1007 : : */
1008 : : static bool
1887 pg@bowt.ie 1009 : 178534 : index_unchanged_by_update(ResultRelInfo *resultRelInfo, EState *estate,
1010 : : IndexInfo *indexInfo, Relation indexRelation)
1011 : : {
1012 : : Bitmapset *updatedCols;
1013 : : Bitmapset *extraUpdatedCols;
1014 : : Bitmapset *allUpdatedCols;
1015 : 178534 : bool hasexpression = false;
1016 : : List *idxExprs;
1017 : :
1018 : : /*
1019 : : * Check cache first
1020 : : */
1523 1021 [ + + ]: 178534 : if (indexInfo->ii_CheckedUnchanged)
1022 : 156577 : return indexInfo->ii_IndexUnchanged;
1023 : 21957 : indexInfo->ii_CheckedUnchanged = true;
1024 : :
1025 : : /*
1026 : : * Check for indexed attribute overlap with updated columns.
1027 : : *
1028 : : * Only do this for key columns. A change to a non-key column within an
1029 : : * INCLUDE index should not be counted here. Non-key column values are
1030 : : * opaque payload state to the index AM, a little like an extra table TID.
1031 : : *
1032 : : * Note that row-level BEFORE triggers won't affect our behavior, since
1033 : : * they don't affect the updatedCols bitmaps generally. It doesn't seem
1034 : : * worth the trouble of checking which attributes were changed directly.
1035 : : */
1036 : 21957 : updatedCols = ExecGetUpdatedCols(resultRelInfo, estate);
1037 : 21957 : extraUpdatedCols = ExecGetExtraUpdatedCols(resultRelInfo, estate);
1887 1038 [ + + ]: 23665 : for (int attr = 0; attr < indexInfo->ii_NumIndexKeyAttrs; attr++)
1039 : : {
1040 : 22687 : int keycol = indexInfo->ii_IndexAttrNumbers[attr];
1041 : :
1042 [ + + ]: 22687 : if (keycol <= 0)
1043 : : {
1044 : : /*
1045 : : * Skip expressions for now, but remember to deal with them later
1046 : : * on
1047 : : */
1048 : 15 : hasexpression = true;
1049 : 15 : continue;
1050 : : }
1051 : :
1052 [ + + ]: 22672 : if (bms_is_member(keycol - FirstLowInvalidHeapAttributeNumber,
1053 [ - + ]: 1693 : updatedCols) ||
1054 : 1693 : bms_is_member(keycol - FirstLowInvalidHeapAttributeNumber,
1055 : : extraUpdatedCols))
1056 : : {
1057 : : /* Changed key column -- don't hint for this index */
1523 1058 : 20979 : indexInfo->ii_IndexUnchanged = false;
1887 1059 : 20979 : return false;
1060 : : }
1061 : : }
1062 : :
1063 : : /*
1064 : : * When we get this far and index has no expressions, return true so that
1065 : : * index_insert() call will go on to pass 'indexUnchanged' = true hint.
1066 : : *
1067 : : * The _absence_ of an indexed key attribute that overlaps with updated
1068 : : * attributes (in addition to the total absence of indexed expressions)
1069 : : * shows that the index as a whole is logically unchanged by UPDATE.
1070 : : */
1071 [ + + ]: 978 : if (!hasexpression)
1072 : : {
1523 1073 : 966 : indexInfo->ii_IndexUnchanged = true;
1887 1074 : 966 : return true;
1075 : : }
1076 : :
1077 : : /*
1078 : : * Need to pass only one bms to expression_tree_walker helper function.
1079 : : * Avoid allocating memory in common case where there are no extra cols.
1080 : : */
1081 [ + - ]: 12 : if (!extraUpdatedCols)
1082 : 12 : allUpdatedCols = updatedCols;
1083 : : else
1887 pg@bowt.ie 1084 :UBC 0 : allUpdatedCols = bms_union(updatedCols, extraUpdatedCols);
1085 : :
1086 : : /*
1087 : : * We have to work slightly harder in the event of indexed expressions,
1088 : : * but the principle is the same as before: try to find columns (Vars,
1089 : : * actually) that overlap with known-updated columns.
1090 : : *
1091 : : * If we find any matching Vars, don't pass hint for index. Otherwise
1092 : : * pass hint.
1093 : : */
1887 pg@bowt.ie 1094 :CBC 12 : idxExprs = RelationGetIndexExpressions(indexRelation);
1095 : 12 : hasexpression = index_expression_changed_walker((Node *) idxExprs,
1096 : : allUpdatedCols);
1097 : 12 : list_free(idxExprs);
1098 [ - + ]: 12 : if (extraUpdatedCols)
1887 pg@bowt.ie 1099 :UBC 0 : bms_free(allUpdatedCols);
1100 : :
1887 pg@bowt.ie 1101 [ + + ]:CBC 12 : if (hasexpression)
1102 : : {
1523 1103 : 9 : indexInfo->ii_IndexUnchanged = false;
1887 1104 : 9 : return false;
1105 : : }
1106 : :
1107 : : /*
1108 : : * Deliberately don't consider index predicates. We should even give the
1109 : : * hint when result rel's "updated tuple" has no corresponding index
1110 : : * tuple, which is possible with a partial index (provided the usual
1111 : : * conditions are met).
1112 : : */
1523 1113 : 3 : indexInfo->ii_IndexUnchanged = true;
1887 1114 : 3 : return true;
1115 : : }
1116 : :
1117 : : /*
1118 : : * Indexed expression helper for index_unchanged_by_update().
1119 : : *
1120 : : * Returns true when Var that appears within allUpdatedCols located.
1121 : : */
1122 : : static bool
1123 : 38 : index_expression_changed_walker(Node *node, Bitmapset *allUpdatedCols)
1124 : : {
1125 [ - + ]: 38 : if (node == NULL)
1887 pg@bowt.ie 1126 :UBC 0 : return false;
1127 : :
1887 pg@bowt.ie 1128 [ + + ]:CBC 38 : if (IsA(node, Var))
1129 : : {
1130 : 12 : Var *var = (Var *) node;
1131 : :
1132 [ + + ]: 12 : if (bms_is_member(var->varattno - FirstLowInvalidHeapAttributeNumber,
1133 : : allUpdatedCols))
1134 : : {
1135 : : /* Var was updated -- indicates that we should not hint */
1136 : 9 : return true;
1137 : : }
1138 : :
1139 : : /* Still haven't found a reason to not pass the hint */
1140 : 3 : return false;
1141 : : }
1142 : :
1143 : 26 : return expression_tree_walker(node, index_expression_changed_walker,
1144 : : allUpdatedCols);
1145 : : }
1146 : :
1147 : : /*
1148 : : * ExecWithoutOverlapsNotEmpty - raise an error if the tuple has an empty
1149 : : * range or multirange in the given attribute.
1150 : : */
1151 : : static void
544 peter@eisentraut.org 1152 : 1081 : ExecWithoutOverlapsNotEmpty(Relation rel, NameData attname, Datum attval, char typtype, Oid atttypid)
1153 : : {
1154 : : bool isempty;
1155 : : RangeType *r;
1156 : : MultirangeType *mr;
1157 : :
1158 [ + + - ]: 1081 : switch (typtype)
1159 : : {
1160 : 619 : case TYPTYPE_RANGE:
1161 : 619 : r = DatumGetRangeTypeP(attval);
1162 : 619 : isempty = RangeIsEmpty(r);
1163 : 619 : break;
1164 : 462 : case TYPTYPE_MULTIRANGE:
1165 : 462 : mr = DatumGetMultirangeTypeP(attval);
1166 : 462 : isempty = MultirangeIsEmpty(mr);
1167 : 462 : break;
544 peter@eisentraut.org 1168 :UBC 0 : default:
1169 [ # # ]: 0 : elog(ERROR, "WITHOUT OVERLAPS column \"%s\" is not a range or multirange",
1170 : : NameStr(attname));
1171 : : }
1172 : :
1173 : : /* Report a CHECK_VIOLATION */
544 peter@eisentraut.org 1174 [ + + ]:CBC 1081 : if (isempty)
1175 [ + - ]: 42 : ereport(ERROR,
1176 : : (errcode(ERRCODE_CHECK_VIOLATION),
1177 : : errmsg("empty WITHOUT OVERLAPS value found in column \"%s\" in relation \"%s\"",
1178 : : NameStr(attname), RelationGetRelationName(rel))));
1179 : 1039 : }
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