Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * ri_triggers.c
4 : *
5 : * Generic trigger procedures for referential integrity constraint
6 : * checks.
7 : *
8 : * Note about memory management: the private hashtables kept here live
9 : * across query and transaction boundaries, in fact they live as long as
10 : * the backend does. This works because the hashtable structures
11 : * themselves are allocated by dynahash.c in its permanent DynaHashCxt,
12 : * and the SPI plans they point to are saved using SPI_keepplan().
13 : * There is not currently any provision for throwing away a no-longer-needed
14 : * plan --- consider improving this someday.
15 : *
16 : *
17 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
18 : *
19 : * src/backend/utils/adt/ri_triggers.c
20 : *
21 : *-------------------------------------------------------------------------
22 : */
23 :
24 : #include "postgres.h"
25 :
26 : #include "access/amapi.h"
27 : #include "access/genam.h"
28 : #include "access/htup_details.h"
29 : #include "access/skey.h"
30 : #include "access/sysattr.h"
31 : #include "access/table.h"
32 : #include "access/tableam.h"
33 : #include "access/xact.h"
34 : #include "catalog/index.h"
35 : #include "catalog/pg_collation.h"
36 : #include "catalog/pg_constraint.h"
37 : #include "catalog/pg_namespace.h"
38 : #include "commands/trigger.h"
39 : #include "executor/executor.h"
40 : #include "executor/spi.h"
41 : #include "lib/ilist.h"
42 : #include "miscadmin.h"
43 : #include "parser/parse_coerce.h"
44 : #include "parser/parse_relation.h"
45 : #include "utils/acl.h"
46 : #include "utils/builtins.h"
47 : #include "utils/datum.h"
48 : #include "utils/fmgroids.h"
49 : #include "utils/guc.h"
50 : #include "utils/hsearch.h"
51 : #include "utils/inval.h"
52 : #include "utils/lsyscache.h"
53 : #include "utils/memutils.h"
54 : #include "utils/rel.h"
55 : #include "utils/rls.h"
56 : #include "utils/ruleutils.h"
57 : #include "utils/snapmgr.h"
58 : #include "utils/syscache.h"
59 :
60 : /*
61 : * Local definitions
62 : */
63 :
64 : #define RI_MAX_NUMKEYS INDEX_MAX_KEYS
65 :
66 : #define RI_INIT_CONSTRAINTHASHSIZE 64
67 : #define RI_INIT_QUERYHASHSIZE (RI_INIT_CONSTRAINTHASHSIZE * 4)
68 :
69 : #define RI_KEYS_ALL_NULL 0
70 : #define RI_KEYS_SOME_NULL 1
71 : #define RI_KEYS_NONE_NULL 2
72 :
73 : /* RI query type codes */
74 : /* these queries are executed against the PK (referenced) table: */
75 : #define RI_PLAN_CHECK_LOOKUPPK 1
76 : #define RI_PLAN_CHECK_LOOKUPPK_FROM_PK 2
77 : #define RI_PLAN_LAST_ON_PK RI_PLAN_CHECK_LOOKUPPK_FROM_PK
78 : /* these queries are executed against the FK (referencing) table: */
79 : #define RI_PLAN_CASCADE_ONDELETE 3
80 : #define RI_PLAN_CASCADE_ONUPDATE 4
81 : #define RI_PLAN_NO_ACTION 5
82 : /* For RESTRICT, the same plan can be used for both ON DELETE and ON UPDATE triggers. */
83 : #define RI_PLAN_RESTRICT 6
84 : #define RI_PLAN_SETNULL_ONDELETE 7
85 : #define RI_PLAN_SETNULL_ONUPDATE 8
86 : #define RI_PLAN_SETDEFAULT_ONDELETE 9
87 : #define RI_PLAN_SETDEFAULT_ONUPDATE 10
88 :
89 : #define MAX_QUOTED_NAME_LEN (NAMEDATALEN*2+3)
90 : #define MAX_QUOTED_REL_NAME_LEN (MAX_QUOTED_NAME_LEN*2)
91 :
92 : #define RIAttName(rel, attnum) NameStr(*attnumAttName(rel, attnum))
93 : #define RIAttType(rel, attnum) attnumTypeId(rel, attnum)
94 : #define RIAttCollation(rel, attnum) attnumCollationId(rel, attnum)
95 :
96 : #define RI_TRIGTYPE_INSERT 1
97 : #define RI_TRIGTYPE_UPDATE 2
98 : #define RI_TRIGTYPE_DELETE 3
99 :
100 : typedef struct FastPathMeta FastPathMeta;
101 :
102 : /*
103 : * RI_ConstraintInfo
104 : *
105 : * Information extracted from an FK pg_constraint entry. This is cached in
106 : * ri_constraint_cache.
107 : *
108 : * Note that pf/pp/ff_eq_oprs may hold the overlaps operator instead of equals
109 : * for the PERIOD part of a temporal foreign key.
110 : */
111 : typedef struct RI_ConstraintInfo
112 : {
113 : Oid constraint_id; /* OID of pg_constraint entry (hash key) */
114 : bool valid; /* successfully initialized? */
115 : Oid constraint_root_id; /* OID of topmost ancestor constraint;
116 : * same as constraint_id if not inherited */
117 : uint32 oidHashValue; /* hash value of constraint_id */
118 : uint32 rootHashValue; /* hash value of constraint_root_id */
119 : NameData conname; /* name of the FK constraint */
120 : Oid pk_relid; /* referenced relation */
121 : Oid fk_relid; /* referencing relation */
122 : char confupdtype; /* foreign key's ON UPDATE action */
123 : char confdeltype; /* foreign key's ON DELETE action */
124 : int ndelsetcols; /* number of columns referenced in ON DELETE
125 : * SET clause */
126 : int16 confdelsetcols[RI_MAX_NUMKEYS]; /* attnums of cols to set on
127 : * delete */
128 : char confmatchtype; /* foreign key's match type */
129 : bool hasperiod; /* if the foreign key uses PERIOD */
130 : int nkeys; /* number of key columns */
131 : int16 pk_attnums[RI_MAX_NUMKEYS]; /* attnums of referenced cols */
132 : int16 fk_attnums[RI_MAX_NUMKEYS]; /* attnums of referencing cols */
133 : Oid pf_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = FK) */
134 : Oid pp_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = PK) */
135 : Oid ff_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (FK = FK) */
136 : Oid period_contained_by_oper; /* anyrange <@ anyrange (or
137 : * multiranges) */
138 : Oid agged_period_contained_by_oper; /* fkattr <@ range_agg(pkattr) */
139 : Oid period_intersect_oper; /* anyrange * anyrange (or
140 : * multiranges) */
141 : dlist_node valid_link; /* Link in list of valid entries */
142 :
143 : Oid conindid;
144 : bool pk_is_partitioned;
145 :
146 : FastPathMeta *fpmeta;
147 : } RI_ConstraintInfo;
148 :
149 : typedef struct RI_CompareHashEntry RI_CompareHashEntry;
150 :
151 : /* Fast-path metadata for RI checks on foreign key referencing tables */
152 : typedef struct FastPathMeta
153 : {
154 : FmgrInfo eq_opr_finfo[RI_MAX_NUMKEYS];
155 : FmgrInfo cast_func_finfo[RI_MAX_NUMKEYS];
156 : RegProcedure regops[RI_MAX_NUMKEYS];
157 : Oid subtypes[RI_MAX_NUMKEYS];
158 : int strats[RI_MAX_NUMKEYS];
159 : AttrNumber index_attnos[RI_MAX_NUMKEYS]; /* index column positions */
160 : } FastPathMeta;
161 :
162 : /*
163 : * RI_QueryKey
164 : *
165 : * The key identifying a prepared SPI plan in our query hashtable
166 : */
167 : typedef struct RI_QueryKey
168 : {
169 : Oid constr_id; /* OID of pg_constraint entry */
170 : int32 constr_queryno; /* query type ID, see RI_PLAN_XXX above */
171 : } RI_QueryKey;
172 :
173 : /*
174 : * RI_QueryHashEntry
175 : */
176 : typedef struct RI_QueryHashEntry
177 : {
178 : RI_QueryKey key;
179 : SPIPlanPtr plan;
180 : } RI_QueryHashEntry;
181 :
182 : /*
183 : * RI_CompareKey
184 : *
185 : * The key identifying an entry showing how to compare two values
186 : */
187 : typedef struct RI_CompareKey
188 : {
189 : Oid eq_opr; /* the equality operator to apply */
190 : Oid typeid; /* the data type to apply it to */
191 : } RI_CompareKey;
192 :
193 : /*
194 : * RI_CompareHashEntry
195 : */
196 : typedef struct RI_CompareHashEntry
197 : {
198 : RI_CompareKey key;
199 : bool valid; /* successfully initialized? */
200 : FmgrInfo eq_opr_finfo; /* call info for equality fn */
201 : FmgrInfo cast_func_finfo; /* in case we must coerce input */
202 : } RI_CompareHashEntry;
203 :
204 : /*
205 : * Maximum number of FK rows buffered before flushing.
206 : *
207 : * Larger batches amortize per-flush overhead and let the SK_SEARCHARRAY
208 : * path walk more leaf pages in a single sorted traversal. But each
209 : * buffered row is a materialized HeapTuple in flush_cxt, and the matched[]
210 : * scan in ri_FastPathFlushArray() is O(batch_size) per index match.
211 : * Benchmarking showed little difference between 16 and 64, with 256
212 : * consistently slower. 64 is a reasonable default.
213 : */
214 : #define RI_FASTPATH_BATCH_SIZE 64
215 :
216 : /*
217 : * RI_FastPathEntry
218 : * Per-constraint cache of resources needed by ri_FastPathBatchFlush().
219 : *
220 : * One entry per constraint, keyed by pg_constraint OID. Created lazily
221 : * by ri_FastPathGetEntry() on first use within a trigger-firing batch
222 : * and torn down by ri_FastPathTeardown() at batch end.
223 : *
224 : * FK tuples are buffered in batch[] across trigger invocations and
225 : * flushed when the buffer fills or the batch ends.
226 : *
227 : * RI_FastPathEntry is not subject to cache invalidation. The cached
228 : * relations are held open with locks for the transaction duration, preventing
229 : * relcache invalidation. The entry itself is torn down at batch end by
230 : * ri_FastPathEndBatch(); on abort, ResourceOwner releases the cached
231 : * relations and the XactCallback NULLs the static cache pointer to prevent
232 : * any subsequent access.
233 : */
234 : typedef struct RI_FastPathEntry
235 : {
236 : Oid conoid; /* hash key: pg_constraint OID */
237 : Oid fk_relid; /* for ri_FastPathEndBatch() */
238 : Relation pk_rel;
239 : Relation idx_rel;
240 : TupleTableSlot *pk_slot;
241 : TupleTableSlot *fk_slot;
242 : MemoryContext flush_cxt; /* short-lived context for per-flush work */
243 :
244 : /*
245 : * TODO: batch[] is HeapTuple[] because the AFTER trigger machinery
246 : * currently passes tuples as HeapTuples. Once trigger infrastructure is
247 : * slotified, this should use a slot array or whatever batched tuple
248 : * storage abstraction exists at that point to be TAM-agnostic.
249 : */
250 : HeapTuple batch[RI_FASTPATH_BATCH_SIZE];
251 : int batch_count;
252 :
253 : /*
254 : * true while this entry's batch is being flushed; guards against
255 : * re-entrant ri_FastPathBatchAdd from user code run during the flush.
256 : */
257 : bool flushing;
258 : } RI_FastPathEntry;
259 :
260 : /*
261 : * Local data
262 : */
263 : static HTAB *ri_constraint_cache = NULL;
264 : static HTAB *ri_query_cache = NULL;
265 : static HTAB *ri_compare_cache = NULL;
266 : static dclist_head ri_constraint_cache_valid_list;
267 :
268 : static HTAB *ri_fastpath_cache = NULL;
269 : static bool ri_fastpath_callback_registered = false;
270 : static bool ri_fastpath_flushing = false;
271 :
272 : /*
273 : * Local function prototypes
274 : */
275 : static bool ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
276 : TupleTableSlot *oldslot,
277 : const RI_ConstraintInfo *riinfo);
278 : static Datum ri_restrict(TriggerData *trigdata, bool is_no_action);
279 : static Datum ri_set(TriggerData *trigdata, bool is_set_null, int tgkind);
280 : static void quoteOneName(char *buffer, const char *name);
281 : static void quoteRelationName(char *buffer, Relation rel);
282 : static void ri_GenerateQual(StringInfo buf,
283 : const char *sep,
284 : const char *leftop, Oid leftoptype,
285 : Oid opoid,
286 : const char *rightop, Oid rightoptype);
287 : static void ri_GenerateQualCollation(StringInfo buf, Oid collation);
288 : static int ri_NullCheck(TupleDesc tupDesc, TupleTableSlot *slot,
289 : const RI_ConstraintInfo *riinfo, bool rel_is_pk);
290 : static void ri_BuildQueryKey(RI_QueryKey *key,
291 : const RI_ConstraintInfo *riinfo,
292 : int32 constr_queryno);
293 : static bool ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
294 : const RI_ConstraintInfo *riinfo, bool rel_is_pk);
295 : static bool ri_CompareWithCast(Oid eq_opr, Oid typeid, Oid collid,
296 : Datum lhs, Datum rhs);
297 :
298 : static void ri_InitHashTables(void);
299 : static void InvalidateConstraintCacheCallBack(Datum arg, SysCacheIdentifier cacheid,
300 : uint32 hashvalue);
301 : static SPIPlanPtr ri_FetchPreparedPlan(RI_QueryKey *key);
302 : static void ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan);
303 : static RI_CompareHashEntry *ri_HashCompareOp(Oid eq_opr, Oid typeid);
304 :
305 : static void ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname,
306 : int tgkind);
307 : static RI_ConstraintInfo *ri_FetchConstraintInfo(Trigger *trigger,
308 : Relation trig_rel, bool rel_is_pk);
309 : static RI_ConstraintInfo *ri_LoadConstraintInfo(Oid constraintOid);
310 : static Oid get_ri_constraint_root(Oid constrOid);
311 : static SPIPlanPtr ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
312 : RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel);
313 : static bool ri_PerformCheck(const RI_ConstraintInfo *riinfo,
314 : RI_QueryKey *qkey, SPIPlanPtr qplan,
315 : Relation fk_rel, Relation pk_rel,
316 : TupleTableSlot *oldslot, TupleTableSlot *newslot,
317 : bool is_restrict,
318 : bool detectNewRows, int expect_OK);
319 : static void ri_FastPathCheck(RI_ConstraintInfo *riinfo,
320 : Relation fk_rel, TupleTableSlot *newslot);
321 : static void ri_FastPathBatchAdd(RI_ConstraintInfo *riinfo,
322 : Relation fk_rel, TupleTableSlot *newslot);
323 : static void ri_FastPathBatchFlush(RI_FastPathEntry *fpentry, Relation fk_rel,
324 : RI_ConstraintInfo *riinfo);
325 : static int ri_FastPathFlushArray(RI_FastPathEntry *fpentry, TupleTableSlot *fk_slot,
326 : const RI_ConstraintInfo *riinfo, Relation fk_rel,
327 : Snapshot snapshot, IndexScanDesc scandesc);
328 : static int ri_FastPathFlushLoop(RI_FastPathEntry *fpentry, TupleTableSlot *fk_slot,
329 : const RI_ConstraintInfo *riinfo, Relation fk_rel,
330 : Snapshot snapshot, IndexScanDesc scandesc);
331 : static bool ri_FastPathProbeOne(Relation pk_rel, Relation idx_rel,
332 : IndexScanDesc scandesc, TupleTableSlot *slot,
333 : Snapshot snapshot, const RI_ConstraintInfo *riinfo,
334 : ScanKeyData *skey, int nkeys);
335 : static bool ri_LockPKTuple(Relation pk_rel, TupleTableSlot *slot, Snapshot snap,
336 : bool *concurrently_updated);
337 : static bool ri_fastpath_is_applicable(const RI_ConstraintInfo *riinfo);
338 : static void ri_CheckPermissions(Relation query_rel);
339 : static bool recheck_matched_pk_tuple(Relation idxrel, ScanKeyData *skeys,
340 : int nkeys, TupleTableSlot *new_slot);
341 : static void build_index_scankeys(const RI_ConstraintInfo *riinfo,
342 : Relation idx_rel, Datum *pk_vals,
343 : char *pk_nulls, ScanKey skeys);
344 : static void ri_populate_fastpath_metadata(RI_ConstraintInfo *riinfo,
345 : Relation fk_rel, Relation idx_rel);
346 : static void ri_ExtractValues(Relation rel, TupleTableSlot *slot,
347 : const RI_ConstraintInfo *riinfo, bool rel_is_pk,
348 : Datum *vals, char *nulls);
349 : pg_noreturn static void ri_ReportViolation(const RI_ConstraintInfo *riinfo,
350 : Relation pk_rel, Relation fk_rel,
351 : TupleTableSlot *violatorslot, TupleDesc tupdesc,
352 : int queryno, bool is_restrict, bool partgone);
353 : static RI_FastPathEntry *ri_FastPathGetEntry(const RI_ConstraintInfo *riinfo,
354 : Relation fk_rel);
355 : static void ri_FastPathEndBatch(void *arg);
356 : static void ri_FastPathTeardown(void);
357 :
358 :
359 : /*
360 : * RI_FKey_check -
361 : *
362 : * Check foreign key existence (combined for INSERT and UPDATE).
363 : */
364 : static Datum
365 606443 : RI_FKey_check(TriggerData *trigdata)
366 : {
367 : RI_ConstraintInfo *riinfo;
368 : Relation fk_rel;
369 : Relation pk_rel;
370 : TupleTableSlot *newslot;
371 : RI_QueryKey qkey;
372 : SPIPlanPtr qplan;
373 :
374 606443 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
375 : trigdata->tg_relation, false);
376 :
377 606443 : if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
378 294 : newslot = trigdata->tg_newslot;
379 : else
380 606149 : newslot = trigdata->tg_trigslot;
381 :
382 : /*
383 : * We should not even consider checking the row if it is no longer valid,
384 : * since it was either deleted (so the deferred check should be skipped)
385 : * or updated (in which case only the latest version of the row should be
386 : * checked). Test its liveness according to SnapshotSelf. We need pin
387 : * and lock on the buffer to call HeapTupleSatisfiesVisibility. Caller
388 : * should be holding pin, but not lock.
389 : */
390 606443 : if (!table_tuple_satisfies_snapshot(trigdata->tg_relation, newslot, SnapshotSelf))
391 40 : return PointerGetDatum(NULL);
392 :
393 606403 : fk_rel = trigdata->tg_relation;
394 :
395 606403 : switch (ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false))
396 : {
397 102 : case RI_KEYS_ALL_NULL:
398 :
399 : /*
400 : * No further check needed - an all-NULL key passes every type of
401 : * foreign key constraint.
402 : */
403 102 : return PointerGetDatum(NULL);
404 :
405 104 : case RI_KEYS_SOME_NULL:
406 :
407 : /*
408 : * This is the only case that differs between the three kinds of
409 : * MATCH.
410 : */
411 104 : switch (riinfo->confmatchtype)
412 : {
413 24 : case FKCONSTR_MATCH_FULL:
414 :
415 : /*
416 : * Not allowed - MATCH FULL says either all or none of the
417 : * attributes can be NULLs
418 : */
419 24 : ereport(ERROR,
420 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
421 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
422 : RelationGetRelationName(fk_rel),
423 : NameStr(riinfo->conname)),
424 : errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
425 : errtableconstraint(fk_rel,
426 : NameStr(riinfo->conname))));
427 : return PointerGetDatum(NULL);
428 :
429 80 : case FKCONSTR_MATCH_SIMPLE:
430 :
431 : /*
432 : * MATCH SIMPLE - if ANY column is null, the key passes
433 : * the constraint.
434 : */
435 80 : return PointerGetDatum(NULL);
436 :
437 : #ifdef NOT_USED
438 : case FKCONSTR_MATCH_PARTIAL:
439 :
440 : /*
441 : * MATCH PARTIAL - all non-null columns must match. (not
442 : * implemented, can be done by modifying the query below
443 : * to only include non-null columns, or by writing a
444 : * special version here)
445 : */
446 : break;
447 : #endif
448 : }
449 :
450 : case RI_KEYS_NONE_NULL:
451 :
452 : /*
453 : * Have a full qualified key - continue below for all three kinds
454 : * of MATCH.
455 : */
456 606197 : break;
457 : }
458 :
459 : /*
460 : * Fast path: probe the PK unique index directly, bypassing SPI.
461 : *
462 : * For non-partitioned, non-temporal FKs, we can skip the SPI machinery
463 : * (plan cache, executor setup, etc.) and do a direct index scan + tuple
464 : * lock. This is semantically equivalent to the SPI path below but avoids
465 : * the per-row executor overhead.
466 : *
467 : * ri_FastPathBatchAdd() and ri_FastPathCheck() report the violation
468 : * themselves if no matching PK row is found, so they only return on
469 : * success.
470 : */
471 606197 : if (ri_fastpath_is_applicable(riinfo))
472 : {
473 1210770 : if (AfterTriggerIsActive() &&
474 605363 : GetCurrentTransactionNestLevel() == 1 &&
475 605223 : !ri_fastpath_flushing)
476 : {
477 : /* Batched path: buffer and probe in groups */
478 605223 : ri_FastPathBatchAdd(riinfo, fk_rel, newslot);
479 : }
480 : else
481 : {
482 : /*
483 : * Per-row path, used when batching is not safe or not applicable:
484 : *
485 : * - ALTER TABLE validation, where no after-trigger firing is
486 : * active;
487 : *
488 : * - any FK check inside a subtransaction, since the batch cache
489 : * is confined to the top transaction level (it cannot be cleanly
490 : * unwound on subxact abort);
491 : *
492 : * - a re-entrant check from user cast/operator code running
493 : * during a batch flush, since adding a cache entry while
494 : * ri_FastPathEndBatch is iterating the cache could leave it
495 : * unflushed.
496 : */
497 184 : ri_FastPathCheck(riinfo, fk_rel, newslot);
498 : }
499 605396 : return PointerGetDatum(NULL);
500 : }
501 :
502 790 : SPI_connect();
503 :
504 : /*
505 : * pk_rel is opened in RowShareLock mode since that's what our eventual
506 : * SELECT FOR KEY SHARE will get on it.
507 : */
508 790 : pk_rel = table_open(riinfo->pk_relid, RowShareLock);
509 :
510 : /* Fetch or prepare a saved plan for the real check */
511 790 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK);
512 :
513 790 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
514 : {
515 : StringInfoData querybuf;
516 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
517 : char attname[MAX_QUOTED_NAME_LEN];
518 : char paramname[16];
519 : const char *querysep;
520 : Oid queryoids[RI_MAX_NUMKEYS];
521 : const char *pk_only;
522 :
523 : /* ----------
524 : * The query string built is
525 : * SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
526 : * FOR KEY SHARE OF x
527 : * The type id's for the $ parameters are those of the
528 : * corresponding FK attributes.
529 : *
530 : * But for temporal FKs we need to make sure
531 : * the FK's range is completely covered.
532 : * So we use this query instead:
533 : * SELECT 1
534 : * FROM (
535 : * SELECT pkperiodatt AS r
536 : * FROM [ONLY] pktable x
537 : * WHERE pkatt1 = $1 [AND ...]
538 : * AND pkperiodatt && $n
539 : * FOR KEY SHARE OF x
540 : * ) x1
541 : * HAVING $n <@ range_agg(x1.r)
542 : * Note if FOR KEY SHARE ever allows GROUP BY and HAVING
543 : * we can make this a bit simpler.
544 : * ----------
545 : */
546 366 : initStringInfo(&querybuf);
547 732 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
548 366 : "" : "ONLY ";
549 366 : quoteRelationName(pkrelname, pk_rel);
550 366 : if (riinfo->hasperiod)
551 : {
552 68 : quoteOneName(attname,
553 68 : RIAttName(pk_rel, riinfo->pk_attnums[riinfo->nkeys - 1]));
554 :
555 68 : appendStringInfo(&querybuf,
556 : "SELECT 1 FROM (SELECT %s AS r FROM %s%s x",
557 : attname, pk_only, pkrelname);
558 : }
559 : else
560 : {
561 298 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
562 : pk_only, pkrelname);
563 : }
564 366 : querysep = "WHERE";
565 816 : for (int i = 0; i < riinfo->nkeys; i++)
566 : {
567 450 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
568 450 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
569 :
570 450 : quoteOneName(attname,
571 450 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
572 450 : sprintf(paramname, "$%d", i + 1);
573 450 : ri_GenerateQual(&querybuf, querysep,
574 : attname, pk_type,
575 : riinfo->pf_eq_oprs[i],
576 : paramname, fk_type);
577 450 : querysep = "AND";
578 450 : queryoids[i] = fk_type;
579 : }
580 366 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
581 366 : if (riinfo->hasperiod)
582 : {
583 68 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[riinfo->nkeys - 1]);
584 :
585 68 : appendStringInfoString(&querybuf, ") x1 HAVING ");
586 68 : sprintf(paramname, "$%d", riinfo->nkeys);
587 68 : ri_GenerateQual(&querybuf, "",
588 : paramname, fk_type,
589 : riinfo->agged_period_contained_by_oper,
590 : "pg_catalog.range_agg", ANYMULTIRANGEOID);
591 68 : appendStringInfoString(&querybuf, "(x1.r)");
592 : }
593 :
594 : /* Prepare and save the plan */
595 366 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
596 : &qkey, fk_rel, pk_rel);
597 : }
598 :
599 : /*
600 : * Now check that foreign key exists in PK table
601 : *
602 : * XXX detectNewRows must be true when a partitioned table is on the
603 : * referenced side. The reason is that our snapshot must be fresh in
604 : * order for the hack in find_inheritance_children() to work.
605 : */
606 790 : ri_PerformCheck(riinfo, &qkey, qplan,
607 : fk_rel, pk_rel,
608 : NULL, newslot,
609 : false,
610 790 : pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE,
611 : SPI_OK_SELECT);
612 :
613 650 : if (SPI_finish() != SPI_OK_FINISH)
614 0 : elog(ERROR, "SPI_finish failed");
615 :
616 650 : table_close(pk_rel, RowShareLock);
617 :
618 650 : return PointerGetDatum(NULL);
619 : }
620 :
621 :
622 : /*
623 : * RI_FKey_check_ins -
624 : *
625 : * Check foreign key existence at insert event on FK table.
626 : */
627 : Datum
628 606149 : RI_FKey_check_ins(PG_FUNCTION_ARGS)
629 : {
630 : /* Check that this is a valid trigger call on the right time and event. */
631 606149 : ri_CheckTrigger(fcinfo, "RI_FKey_check_ins", RI_TRIGTYPE_INSERT);
632 :
633 : /* Share code with UPDATE case. */
634 606149 : return RI_FKey_check((TriggerData *) fcinfo->context);
635 : }
636 :
637 :
638 : /*
639 : * RI_FKey_check_upd -
640 : *
641 : * Check foreign key existence at update event on FK table.
642 : */
643 : Datum
644 294 : RI_FKey_check_upd(PG_FUNCTION_ARGS)
645 : {
646 : /* Check that this is a valid trigger call on the right time and event. */
647 294 : ri_CheckTrigger(fcinfo, "RI_FKey_check_upd", RI_TRIGTYPE_UPDATE);
648 :
649 : /* Share code with INSERT case. */
650 294 : return RI_FKey_check((TriggerData *) fcinfo->context);
651 : }
652 :
653 :
654 : /*
655 : * ri_Check_Pk_Match
656 : *
657 : * Check to see if another PK row has been created that provides the same
658 : * key values as the "oldslot" that's been modified or deleted in our trigger
659 : * event. Returns true if a match is found in the PK table.
660 : *
661 : * We assume the caller checked that the oldslot contains no NULL key values,
662 : * since otherwise a match is impossible.
663 : */
664 : static bool
665 523 : ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
666 : TupleTableSlot *oldslot,
667 : const RI_ConstraintInfo *riinfo)
668 : {
669 : SPIPlanPtr qplan;
670 : RI_QueryKey qkey;
671 : bool result;
672 :
673 : /* Only called for non-null rows */
674 : Assert(ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) == RI_KEYS_NONE_NULL);
675 :
676 523 : SPI_connect();
677 :
678 : /*
679 : * Fetch or prepare a saved plan for checking PK table with values coming
680 : * from a PK row
681 : */
682 523 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK_FROM_PK);
683 :
684 523 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
685 : {
686 : StringInfoData querybuf;
687 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
688 : char attname[MAX_QUOTED_NAME_LEN];
689 : char paramname[16];
690 : const char *querysep;
691 : const char *pk_only;
692 : Oid queryoids[RI_MAX_NUMKEYS];
693 :
694 : /* ----------
695 : * The query string built is
696 : * SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
697 : * FOR KEY SHARE OF x
698 : * The type id's for the $ parameters are those of the
699 : * PK attributes themselves.
700 : *
701 : * But for temporal FKs we need to make sure
702 : * the old PK's range is completely covered.
703 : * So we use this query instead:
704 : * SELECT 1
705 : * FROM (
706 : * SELECT pkperiodatt AS r
707 : * FROM [ONLY] pktable x
708 : * WHERE pkatt1 = $1 [AND ...]
709 : * AND pkperiodatt && $n
710 : * FOR KEY SHARE OF x
711 : * ) x1
712 : * HAVING $n <@ range_agg(x1.r)
713 : * Note if FOR KEY SHARE ever allows GROUP BY and HAVING
714 : * we can make this a bit simpler.
715 : * ----------
716 : */
717 243 : initStringInfo(&querybuf);
718 486 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
719 243 : "" : "ONLY ";
720 243 : quoteRelationName(pkrelname, pk_rel);
721 243 : if (riinfo->hasperiod)
722 : {
723 0 : quoteOneName(attname, RIAttName(pk_rel, riinfo->pk_attnums[riinfo->nkeys - 1]));
724 :
725 0 : appendStringInfo(&querybuf,
726 : "SELECT 1 FROM (SELECT %s AS r FROM %s%s x",
727 : attname, pk_only, pkrelname);
728 : }
729 : else
730 : {
731 243 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
732 : pk_only, pkrelname);
733 : }
734 243 : querysep = "WHERE";
735 568 : for (int i = 0; i < riinfo->nkeys; i++)
736 : {
737 325 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
738 :
739 325 : quoteOneName(attname,
740 325 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
741 325 : sprintf(paramname, "$%d", i + 1);
742 325 : ri_GenerateQual(&querybuf, querysep,
743 : attname, pk_type,
744 325 : riinfo->pp_eq_oprs[i],
745 : paramname, pk_type);
746 325 : querysep = "AND";
747 325 : queryoids[i] = pk_type;
748 : }
749 243 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
750 243 : if (riinfo->hasperiod)
751 : {
752 0 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[riinfo->nkeys - 1]);
753 :
754 0 : appendStringInfoString(&querybuf, ") x1 HAVING ");
755 0 : sprintf(paramname, "$%d", riinfo->nkeys);
756 0 : ri_GenerateQual(&querybuf, "",
757 : paramname, fk_type,
758 0 : riinfo->agged_period_contained_by_oper,
759 : "pg_catalog.range_agg", ANYMULTIRANGEOID);
760 0 : appendStringInfoString(&querybuf, "(x1.r)");
761 : }
762 :
763 : /* Prepare and save the plan */
764 243 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
765 : &qkey, fk_rel, pk_rel);
766 : }
767 :
768 : /*
769 : * We have a plan now. Run it.
770 : */
771 523 : result = ri_PerformCheck(riinfo, &qkey, qplan,
772 : fk_rel, pk_rel,
773 : oldslot, NULL,
774 : false,
775 : true, /* treat like update */
776 : SPI_OK_SELECT);
777 :
778 523 : if (SPI_finish() != SPI_OK_FINISH)
779 0 : elog(ERROR, "SPI_finish failed");
780 :
781 523 : return result;
782 : }
783 :
784 :
785 : /*
786 : * RI_FKey_noaction_del -
787 : *
788 : * Give an error and roll back the current transaction if the
789 : * delete has resulted in a violation of the given referential
790 : * integrity constraint.
791 : */
792 : Datum
793 313 : RI_FKey_noaction_del(PG_FUNCTION_ARGS)
794 : {
795 : /* Check that this is a valid trigger call on the right time and event. */
796 313 : ri_CheckTrigger(fcinfo, "RI_FKey_noaction_del", RI_TRIGTYPE_DELETE);
797 :
798 : /* Share code with RESTRICT/UPDATE cases. */
799 313 : return ri_restrict((TriggerData *) fcinfo->context, true);
800 : }
801 :
802 : /*
803 : * RI_FKey_restrict_del -
804 : *
805 : * Restrict delete from PK table to rows unreferenced by foreign key.
806 : *
807 : * The SQL standard intends that this referential action occur exactly when
808 : * the delete is performed, rather than after. This appears to be
809 : * the only difference between "NO ACTION" and "RESTRICT". In Postgres
810 : * we still implement this as an AFTER trigger, but it's non-deferrable.
811 : */
812 : Datum
813 8 : RI_FKey_restrict_del(PG_FUNCTION_ARGS)
814 : {
815 : /* Check that this is a valid trigger call on the right time and event. */
816 8 : ri_CheckTrigger(fcinfo, "RI_FKey_restrict_del", RI_TRIGTYPE_DELETE);
817 :
818 : /* Share code with NO ACTION/UPDATE cases. */
819 8 : return ri_restrict((TriggerData *) fcinfo->context, false);
820 : }
821 :
822 : /*
823 : * RI_FKey_noaction_upd -
824 : *
825 : * Give an error and roll back the current transaction if the
826 : * update has resulted in a violation of the given referential
827 : * integrity constraint.
828 : */
829 : Datum
830 356 : RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
831 : {
832 : /* Check that this is a valid trigger call on the right time and event. */
833 356 : ri_CheckTrigger(fcinfo, "RI_FKey_noaction_upd", RI_TRIGTYPE_UPDATE);
834 :
835 : /* Share code with RESTRICT/DELETE cases. */
836 356 : return ri_restrict((TriggerData *) fcinfo->context, true);
837 : }
838 :
839 : /*
840 : * RI_FKey_restrict_upd -
841 : *
842 : * Restrict update of PK to rows unreferenced by foreign key.
843 : *
844 : * The SQL standard intends that this referential action occur exactly when
845 : * the update is performed, rather than after. This appears to be
846 : * the only difference between "NO ACTION" and "RESTRICT". In Postgres
847 : * we still implement this as an AFTER trigger, but it's non-deferrable.
848 : */
849 : Datum
850 20 : RI_FKey_restrict_upd(PG_FUNCTION_ARGS)
851 : {
852 : /* Check that this is a valid trigger call on the right time and event. */
853 20 : ri_CheckTrigger(fcinfo, "RI_FKey_restrict_upd", RI_TRIGTYPE_UPDATE);
854 :
855 : /* Share code with NO ACTION/DELETE cases. */
856 20 : return ri_restrict((TriggerData *) fcinfo->context, false);
857 : }
858 :
859 : /*
860 : * ri_restrict -
861 : *
862 : * Common code for ON DELETE RESTRICT, ON DELETE NO ACTION,
863 : * ON UPDATE RESTRICT, and ON UPDATE NO ACTION.
864 : */
865 : static Datum
866 785 : ri_restrict(TriggerData *trigdata, bool is_no_action)
867 : {
868 : const RI_ConstraintInfo *riinfo;
869 : Relation fk_rel;
870 : Relation pk_rel;
871 : TupleTableSlot *oldslot;
872 : RI_QueryKey qkey;
873 : SPIPlanPtr qplan;
874 :
875 785 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
876 : trigdata->tg_relation, true);
877 :
878 : /*
879 : * Get the relation descriptors of the FK and PK tables and the old tuple.
880 : *
881 : * fk_rel is opened in RowShareLock mode since that's what our eventual
882 : * SELECT FOR KEY SHARE will get on it.
883 : */
884 785 : fk_rel = table_open(riinfo->fk_relid, RowShareLock);
885 785 : pk_rel = trigdata->tg_relation;
886 785 : oldslot = trigdata->tg_trigslot;
887 :
888 : /*
889 : * If another PK row now exists providing the old key values, we should
890 : * not do anything. However, this check should only be made in the NO
891 : * ACTION case; in RESTRICT cases we don't wish to allow another row to be
892 : * substituted.
893 : *
894 : * If the foreign key has PERIOD, we incorporate looking for replacement
895 : * rows in the main SQL query below, so we needn't do it here.
896 : */
897 1308 : if (is_no_action && !riinfo->hasperiod &&
898 523 : ri_Check_Pk_Match(pk_rel, fk_rel, oldslot, riinfo))
899 : {
900 38 : table_close(fk_rel, RowShareLock);
901 38 : return PointerGetDatum(NULL);
902 : }
903 :
904 747 : SPI_connect();
905 :
906 : /*
907 : * Fetch or prepare a saved plan for the restrict lookup (it's the same
908 : * query for delete and update cases)
909 : */
910 747 : ri_BuildQueryKey(&qkey, riinfo, is_no_action ? RI_PLAN_NO_ACTION : RI_PLAN_RESTRICT);
911 :
912 747 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
913 : {
914 : StringInfoData querybuf;
915 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
916 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
917 : char attname[MAX_QUOTED_NAME_LEN];
918 : char periodattname[MAX_QUOTED_NAME_LEN];
919 : char paramname[16];
920 : const char *querysep;
921 : Oid queryoids[RI_MAX_NUMKEYS];
922 : const char *fk_only;
923 :
924 : /* ----------
925 : * The query string built is
926 : * SELECT 1 FROM [ONLY] <fktable> x WHERE $1 = fkatt1 [AND ...]
927 : * FOR KEY SHARE OF x
928 : * The type id's for the $ parameters are those of the
929 : * corresponding PK attributes.
930 : * ----------
931 : */
932 308 : initStringInfo(&querybuf);
933 616 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
934 308 : "" : "ONLY ";
935 308 : quoteRelationName(fkrelname, fk_rel);
936 308 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
937 : fk_only, fkrelname);
938 308 : querysep = "WHERE";
939 789 : for (int i = 0; i < riinfo->nkeys; i++)
940 : {
941 481 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
942 481 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
943 :
944 481 : quoteOneName(attname,
945 481 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
946 481 : sprintf(paramname, "$%d", i + 1);
947 481 : ri_GenerateQual(&querybuf, querysep,
948 : paramname, pk_type,
949 481 : riinfo->pf_eq_oprs[i],
950 : attname, fk_type);
951 481 : querysep = "AND";
952 481 : queryoids[i] = pk_type;
953 : }
954 :
955 : /*----------
956 : * For temporal foreign keys, a reference could still be valid if the
957 : * referenced range didn't change too much. Also if a referencing
958 : * range extends past the current PK row, we don't want to check that
959 : * part: some other PK row should fulfill it. We only want to check
960 : * the part matching the PK record we've changed. Therefore to find
961 : * invalid records we do this:
962 : *
963 : * SELECT 1 FROM [ONLY] <fktable> x WHERE $1 = x.fkatt1 [AND ...]
964 : * -- begin temporal
965 : * AND $n && x.fkperiod
966 : * AND NOT coalesce((x.fkperiod * $n) <@
967 : * (SELECT range_agg(r)
968 : * FROM (SELECT y.pkperiod r
969 : * FROM [ONLY] <pktable> y
970 : * WHERE $1 = y.pkatt1 [AND ...] AND $n && y.pkperiod
971 : * FOR KEY SHARE OF y) y2), false)
972 : * -- end temporal
973 : * FOR KEY SHARE OF x
974 : *
975 : * We need the coalesce in case the first subquery returns no rows.
976 : * We need the second subquery because FOR KEY SHARE doesn't support
977 : * aggregate queries.
978 : */
979 308 : if (riinfo->hasperiod && is_no_action)
980 : {
981 91 : Oid pk_period_type = RIAttType(pk_rel, riinfo->pk_attnums[riinfo->nkeys - 1]);
982 91 : Oid fk_period_type = RIAttType(fk_rel, riinfo->fk_attnums[riinfo->nkeys - 1]);
983 : StringInfoData intersectbuf;
984 : StringInfoData replacementsbuf;
985 182 : char *pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
986 91 : "" : "ONLY ";
987 :
988 91 : quoteOneName(attname, RIAttName(fk_rel, riinfo->fk_attnums[riinfo->nkeys - 1]));
989 91 : sprintf(paramname, "$%d", riinfo->nkeys);
990 :
991 91 : appendStringInfoString(&querybuf, " AND NOT coalesce(");
992 :
993 : /* Intersect the fk with the old pk range */
994 91 : initStringInfo(&intersectbuf);
995 91 : appendStringInfoChar(&intersectbuf, '(');
996 91 : ri_GenerateQual(&intersectbuf, "",
997 : attname, fk_period_type,
998 91 : riinfo->period_intersect_oper,
999 : paramname, pk_period_type);
1000 91 : appendStringInfoChar(&intersectbuf, ')');
1001 :
1002 : /* Find the remaining history */
1003 91 : initStringInfo(&replacementsbuf);
1004 91 : appendStringInfoString(&replacementsbuf, "(SELECT pg_catalog.range_agg(r) FROM ");
1005 :
1006 91 : quoteOneName(periodattname, RIAttName(pk_rel, riinfo->pk_attnums[riinfo->nkeys - 1]));
1007 91 : quoteRelationName(pkrelname, pk_rel);
1008 91 : appendStringInfo(&replacementsbuf, "(SELECT y.%s r FROM %s%s y",
1009 : periodattname, pk_only, pkrelname);
1010 :
1011 : /* Restrict pk rows to what matches */
1012 91 : querysep = "WHERE";
1013 273 : for (int i = 0; i < riinfo->nkeys; i++)
1014 : {
1015 182 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1016 :
1017 182 : quoteOneName(attname,
1018 182 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
1019 182 : sprintf(paramname, "$%d", i + 1);
1020 182 : ri_GenerateQual(&replacementsbuf, querysep,
1021 : paramname, pk_type,
1022 182 : riinfo->pp_eq_oprs[i],
1023 : attname, pk_type);
1024 182 : querysep = "AND";
1025 182 : queryoids[i] = pk_type;
1026 : }
1027 91 : appendStringInfoString(&replacementsbuf, " FOR KEY SHARE OF y) y2)");
1028 :
1029 91 : ri_GenerateQual(&querybuf, "",
1030 91 : intersectbuf.data, fk_period_type,
1031 91 : riinfo->agged_period_contained_by_oper,
1032 91 : replacementsbuf.data, ANYMULTIRANGEOID);
1033 : /* end of coalesce: */
1034 91 : appendStringInfoString(&querybuf, ", false)");
1035 : }
1036 :
1037 308 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
1038 :
1039 : /* Prepare and save the plan */
1040 308 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
1041 : &qkey, fk_rel, pk_rel);
1042 : }
1043 :
1044 : /*
1045 : * We have a plan now. Run it to check for existing references.
1046 : */
1047 747 : ri_PerformCheck(riinfo, &qkey, qplan,
1048 : fk_rel, pk_rel,
1049 : oldslot, NULL,
1050 : !is_no_action,
1051 : true, /* must detect new rows */
1052 747 : SPI_OK_SELECT);
1053 :
1054 417 : if (SPI_finish() != SPI_OK_FINISH)
1055 0 : elog(ERROR, "SPI_finish failed");
1056 :
1057 417 : table_close(fk_rel, RowShareLock);
1058 :
1059 417 : return PointerGetDatum(NULL);
1060 : }
1061 :
1062 :
1063 : /*
1064 : * RI_FKey_cascade_del -
1065 : *
1066 : * Cascaded delete foreign key references at delete event on PK table.
1067 : */
1068 : Datum
1069 98 : RI_FKey_cascade_del(PG_FUNCTION_ARGS)
1070 : {
1071 98 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
1072 : const RI_ConstraintInfo *riinfo;
1073 : Relation fk_rel;
1074 : Relation pk_rel;
1075 : TupleTableSlot *oldslot;
1076 : RI_QueryKey qkey;
1077 : SPIPlanPtr qplan;
1078 :
1079 : /* Check that this is a valid trigger call on the right time and event. */
1080 98 : ri_CheckTrigger(fcinfo, "RI_FKey_cascade_del", RI_TRIGTYPE_DELETE);
1081 :
1082 98 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
1083 : trigdata->tg_relation, true);
1084 :
1085 : /*
1086 : * Get the relation descriptors of the FK and PK tables and the old tuple.
1087 : *
1088 : * fk_rel is opened in RowExclusiveLock mode since that's what our
1089 : * eventual DELETE will get on it.
1090 : */
1091 98 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
1092 98 : pk_rel = trigdata->tg_relation;
1093 98 : oldslot = trigdata->tg_trigslot;
1094 :
1095 98 : SPI_connect();
1096 :
1097 : /* Fetch or prepare a saved plan for the cascaded delete */
1098 98 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_ONDELETE);
1099 :
1100 98 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
1101 : {
1102 : StringInfoData querybuf;
1103 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1104 : char attname[MAX_QUOTED_NAME_LEN];
1105 : char paramname[16];
1106 : const char *querysep;
1107 : Oid queryoids[RI_MAX_NUMKEYS];
1108 : const char *fk_only;
1109 :
1110 : /* ----------
1111 : * The query string built is
1112 : * DELETE FROM [ONLY] <fktable> WHERE $1 = fkatt1 [AND ...]
1113 : * The type id's for the $ parameters are those of the
1114 : * corresponding PK attributes.
1115 : * ----------
1116 : */
1117 58 : initStringInfo(&querybuf);
1118 116 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1119 58 : "" : "ONLY ";
1120 58 : quoteRelationName(fkrelname, fk_rel);
1121 58 : appendStringInfo(&querybuf, "DELETE FROM %s%s",
1122 : fk_only, fkrelname);
1123 58 : querysep = "WHERE";
1124 128 : for (int i = 0; i < riinfo->nkeys; i++)
1125 : {
1126 70 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1127 70 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1128 :
1129 70 : quoteOneName(attname,
1130 70 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1131 70 : sprintf(paramname, "$%d", i + 1);
1132 70 : ri_GenerateQual(&querybuf, querysep,
1133 : paramname, pk_type,
1134 70 : riinfo->pf_eq_oprs[i],
1135 : attname, fk_type);
1136 70 : querysep = "AND";
1137 70 : queryoids[i] = pk_type;
1138 : }
1139 :
1140 : /* Prepare and save the plan */
1141 58 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
1142 : &qkey, fk_rel, pk_rel);
1143 : }
1144 :
1145 : /*
1146 : * We have a plan now. Build up the arguments from the key values in the
1147 : * deleted PK tuple and delete the referencing rows
1148 : */
1149 98 : ri_PerformCheck(riinfo, &qkey, qplan,
1150 : fk_rel, pk_rel,
1151 : oldslot, NULL,
1152 : false,
1153 : true, /* must detect new rows */
1154 : SPI_OK_DELETE);
1155 :
1156 97 : if (SPI_finish() != SPI_OK_FINISH)
1157 0 : elog(ERROR, "SPI_finish failed");
1158 :
1159 97 : table_close(fk_rel, RowExclusiveLock);
1160 :
1161 97 : return PointerGetDatum(NULL);
1162 : }
1163 :
1164 :
1165 : /*
1166 : * RI_FKey_cascade_upd -
1167 : *
1168 : * Cascaded update foreign key references at update event on PK table.
1169 : */
1170 : Datum
1171 144 : RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
1172 : {
1173 144 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
1174 : const RI_ConstraintInfo *riinfo;
1175 : Relation fk_rel;
1176 : Relation pk_rel;
1177 : TupleTableSlot *newslot;
1178 : TupleTableSlot *oldslot;
1179 : RI_QueryKey qkey;
1180 : SPIPlanPtr qplan;
1181 :
1182 : /* Check that this is a valid trigger call on the right time and event. */
1183 144 : ri_CheckTrigger(fcinfo, "RI_FKey_cascade_upd", RI_TRIGTYPE_UPDATE);
1184 :
1185 144 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
1186 : trigdata->tg_relation, true);
1187 :
1188 : /*
1189 : * Get the relation descriptors of the FK and PK tables and the new and
1190 : * old tuple.
1191 : *
1192 : * fk_rel is opened in RowExclusiveLock mode since that's what our
1193 : * eventual UPDATE will get on it.
1194 : */
1195 144 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
1196 144 : pk_rel = trigdata->tg_relation;
1197 144 : newslot = trigdata->tg_newslot;
1198 144 : oldslot = trigdata->tg_trigslot;
1199 :
1200 144 : SPI_connect();
1201 :
1202 : /* Fetch or prepare a saved plan for the cascaded update */
1203 144 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_ONUPDATE);
1204 :
1205 144 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
1206 : {
1207 : StringInfoData querybuf;
1208 : StringInfoData qualbuf;
1209 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1210 : char attname[MAX_QUOTED_NAME_LEN];
1211 : char paramname[16];
1212 : const char *querysep;
1213 : const char *qualsep;
1214 : Oid queryoids[RI_MAX_NUMKEYS * 2];
1215 : const char *fk_only;
1216 :
1217 : /* ----------
1218 : * The query string built is
1219 : * UPDATE [ONLY] <fktable> SET fkatt1 = $1 [, ...]
1220 : * WHERE $n = fkatt1 [AND ...]
1221 : * The type id's for the $ parameters are those of the
1222 : * corresponding PK attributes. Note that we are assuming
1223 : * there is an assignment cast from the PK to the FK type;
1224 : * else the parser will fail.
1225 : * ----------
1226 : */
1227 85 : initStringInfo(&querybuf);
1228 85 : initStringInfo(&qualbuf);
1229 170 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1230 85 : "" : "ONLY ";
1231 85 : quoteRelationName(fkrelname, fk_rel);
1232 85 : appendStringInfo(&querybuf, "UPDATE %s%s SET",
1233 : fk_only, fkrelname);
1234 85 : querysep = "";
1235 85 : qualsep = "WHERE";
1236 188 : for (int i = 0, j = riinfo->nkeys; i < riinfo->nkeys; i++, j++)
1237 : {
1238 103 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1239 103 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1240 :
1241 103 : quoteOneName(attname,
1242 103 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1243 103 : appendStringInfo(&querybuf,
1244 : "%s %s = $%d",
1245 : querysep, attname, i + 1);
1246 103 : sprintf(paramname, "$%d", j + 1);
1247 103 : ri_GenerateQual(&qualbuf, qualsep,
1248 : paramname, pk_type,
1249 103 : riinfo->pf_eq_oprs[i],
1250 : attname, fk_type);
1251 103 : querysep = ",";
1252 103 : qualsep = "AND";
1253 103 : queryoids[i] = pk_type;
1254 103 : queryoids[j] = pk_type;
1255 : }
1256 85 : appendBinaryStringInfo(&querybuf, qualbuf.data, qualbuf.len);
1257 :
1258 : /* Prepare and save the plan */
1259 85 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys * 2, queryoids,
1260 : &qkey, fk_rel, pk_rel);
1261 : }
1262 :
1263 : /*
1264 : * We have a plan now. Run it to update the existing references.
1265 : */
1266 144 : ri_PerformCheck(riinfo, &qkey, qplan,
1267 : fk_rel, pk_rel,
1268 : oldslot, newslot,
1269 : false,
1270 : true, /* must detect new rows */
1271 : SPI_OK_UPDATE);
1272 :
1273 144 : if (SPI_finish() != SPI_OK_FINISH)
1274 0 : elog(ERROR, "SPI_finish failed");
1275 :
1276 144 : table_close(fk_rel, RowExclusiveLock);
1277 :
1278 144 : return PointerGetDatum(NULL);
1279 : }
1280 :
1281 :
1282 : /*
1283 : * RI_FKey_setnull_del -
1284 : *
1285 : * Set foreign key references to NULL values at delete event on PK table.
1286 : */
1287 : Datum
1288 65 : RI_FKey_setnull_del(PG_FUNCTION_ARGS)
1289 : {
1290 : /* Check that this is a valid trigger call on the right time and event. */
1291 65 : ri_CheckTrigger(fcinfo, "RI_FKey_setnull_del", RI_TRIGTYPE_DELETE);
1292 :
1293 : /* Share code with UPDATE case */
1294 65 : return ri_set((TriggerData *) fcinfo->context, true, RI_TRIGTYPE_DELETE);
1295 : }
1296 :
1297 : /*
1298 : * RI_FKey_setnull_upd -
1299 : *
1300 : * Set foreign key references to NULL at update event on PK table.
1301 : */
1302 : Datum
1303 20 : RI_FKey_setnull_upd(PG_FUNCTION_ARGS)
1304 : {
1305 : /* Check that this is a valid trigger call on the right time and event. */
1306 20 : ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
1307 :
1308 : /* Share code with DELETE case */
1309 20 : return ri_set((TriggerData *) fcinfo->context, true, RI_TRIGTYPE_UPDATE);
1310 : }
1311 :
1312 : /*
1313 : * RI_FKey_setdefault_del -
1314 : *
1315 : * Set foreign key references to defaults at delete event on PK table.
1316 : */
1317 : Datum
1318 56 : RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
1319 : {
1320 : /* Check that this is a valid trigger call on the right time and event. */
1321 56 : ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_del", RI_TRIGTYPE_DELETE);
1322 :
1323 : /* Share code with UPDATE case */
1324 56 : return ri_set((TriggerData *) fcinfo->context, false, RI_TRIGTYPE_DELETE);
1325 : }
1326 :
1327 : /*
1328 : * RI_FKey_setdefault_upd -
1329 : *
1330 : * Set foreign key references to defaults at update event on PK table.
1331 : */
1332 : Datum
1333 32 : RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
1334 : {
1335 : /* Check that this is a valid trigger call on the right time and event. */
1336 32 : ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
1337 :
1338 : /* Share code with DELETE case */
1339 32 : return ri_set((TriggerData *) fcinfo->context, false, RI_TRIGTYPE_UPDATE);
1340 : }
1341 :
1342 : /*
1343 : * ri_set -
1344 : *
1345 : * Common code for ON DELETE SET NULL, ON DELETE SET DEFAULT, ON UPDATE SET
1346 : * NULL, and ON UPDATE SET DEFAULT.
1347 : */
1348 : static Datum
1349 173 : ri_set(TriggerData *trigdata, bool is_set_null, int tgkind)
1350 : {
1351 : const RI_ConstraintInfo *riinfo;
1352 : Relation fk_rel;
1353 : Relation pk_rel;
1354 : TupleTableSlot *oldslot;
1355 : RI_QueryKey qkey;
1356 : SPIPlanPtr qplan;
1357 : int32 queryno;
1358 :
1359 173 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
1360 : trigdata->tg_relation, true);
1361 :
1362 : /*
1363 : * Get the relation descriptors of the FK and PK tables and the old tuple.
1364 : *
1365 : * fk_rel is opened in RowExclusiveLock mode since that's what our
1366 : * eventual UPDATE will get on it.
1367 : */
1368 173 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
1369 173 : pk_rel = trigdata->tg_relation;
1370 173 : oldslot = trigdata->tg_trigslot;
1371 :
1372 173 : SPI_connect();
1373 :
1374 : /*
1375 : * Fetch or prepare a saved plan for the trigger.
1376 : */
1377 173 : switch (tgkind)
1378 : {
1379 52 : case RI_TRIGTYPE_UPDATE:
1380 52 : queryno = is_set_null
1381 : ? RI_PLAN_SETNULL_ONUPDATE
1382 52 : : RI_PLAN_SETDEFAULT_ONUPDATE;
1383 52 : break;
1384 121 : case RI_TRIGTYPE_DELETE:
1385 121 : queryno = is_set_null
1386 : ? RI_PLAN_SETNULL_ONDELETE
1387 121 : : RI_PLAN_SETDEFAULT_ONDELETE;
1388 121 : break;
1389 0 : default:
1390 0 : elog(ERROR, "invalid tgkind passed to ri_set");
1391 : }
1392 :
1393 173 : ri_BuildQueryKey(&qkey, riinfo, queryno);
1394 :
1395 173 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
1396 : {
1397 : StringInfoData querybuf;
1398 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1399 : char attname[MAX_QUOTED_NAME_LEN];
1400 : char paramname[16];
1401 : const char *querysep;
1402 : const char *qualsep;
1403 : Oid queryoids[RI_MAX_NUMKEYS];
1404 : const char *fk_only;
1405 : int num_cols_to_set;
1406 : const int16 *set_cols;
1407 :
1408 102 : switch (tgkind)
1409 : {
1410 33 : case RI_TRIGTYPE_UPDATE:
1411 33 : num_cols_to_set = riinfo->nkeys;
1412 33 : set_cols = riinfo->fk_attnums;
1413 33 : break;
1414 69 : case RI_TRIGTYPE_DELETE:
1415 :
1416 : /*
1417 : * If confdelsetcols are present, then we only update the
1418 : * columns specified in that array, otherwise we update all
1419 : * the referencing columns.
1420 : */
1421 69 : if (riinfo->ndelsetcols != 0)
1422 : {
1423 16 : num_cols_to_set = riinfo->ndelsetcols;
1424 16 : set_cols = riinfo->confdelsetcols;
1425 : }
1426 : else
1427 : {
1428 53 : num_cols_to_set = riinfo->nkeys;
1429 53 : set_cols = riinfo->fk_attnums;
1430 : }
1431 69 : break;
1432 0 : default:
1433 0 : elog(ERROR, "invalid tgkind passed to ri_set");
1434 : }
1435 :
1436 : /* ----------
1437 : * The query string built is
1438 : * UPDATE [ONLY] <fktable> SET fkatt1 = {NULL|DEFAULT} [, ...]
1439 : * WHERE $1 = fkatt1 [AND ...]
1440 : * The type id's for the $ parameters are those of the
1441 : * corresponding PK attributes.
1442 : * ----------
1443 : */
1444 102 : initStringInfo(&querybuf);
1445 204 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1446 102 : "" : "ONLY ";
1447 102 : quoteRelationName(fkrelname, fk_rel);
1448 102 : appendStringInfo(&querybuf, "UPDATE %s%s SET",
1449 : fk_only, fkrelname);
1450 :
1451 : /*
1452 : * Add assignment clauses
1453 : */
1454 102 : querysep = "";
1455 272 : for (int i = 0; i < num_cols_to_set; i++)
1456 : {
1457 170 : quoteOneName(attname, RIAttName(fk_rel, set_cols[i]));
1458 170 : appendStringInfo(&querybuf,
1459 : "%s %s = %s",
1460 : querysep, attname,
1461 : is_set_null ? "NULL" : "DEFAULT");
1462 170 : querysep = ",";
1463 : }
1464 :
1465 : /*
1466 : * Add WHERE clause
1467 : */
1468 102 : qualsep = "WHERE";
1469 288 : for (int i = 0; i < riinfo->nkeys; i++)
1470 : {
1471 186 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1472 186 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1473 :
1474 186 : quoteOneName(attname,
1475 186 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1476 :
1477 186 : sprintf(paramname, "$%d", i + 1);
1478 186 : ri_GenerateQual(&querybuf, qualsep,
1479 : paramname, pk_type,
1480 186 : riinfo->pf_eq_oprs[i],
1481 : attname, fk_type);
1482 186 : qualsep = "AND";
1483 186 : queryoids[i] = pk_type;
1484 : }
1485 :
1486 : /* Prepare and save the plan */
1487 102 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
1488 : &qkey, fk_rel, pk_rel);
1489 : }
1490 :
1491 : /*
1492 : * We have a plan now. Run it to update the existing references.
1493 : */
1494 173 : ri_PerformCheck(riinfo, &qkey, qplan,
1495 : fk_rel, pk_rel,
1496 : oldslot, NULL,
1497 : false,
1498 : true, /* must detect new rows */
1499 : SPI_OK_UPDATE);
1500 :
1501 172 : if (SPI_finish() != SPI_OK_FINISH)
1502 0 : elog(ERROR, "SPI_finish failed");
1503 :
1504 172 : table_close(fk_rel, RowExclusiveLock);
1505 :
1506 172 : if (is_set_null)
1507 84 : return PointerGetDatum(NULL);
1508 : else
1509 : {
1510 : /*
1511 : * If we just deleted or updated the PK row whose key was equal to the
1512 : * FK columns' default values, and a referencing row exists in the FK
1513 : * table, we would have updated that row to the same values it already
1514 : * had --- and RI_FKey_fk_upd_check_required would hence believe no
1515 : * check is necessary. So we need to do another lookup now and in
1516 : * case a reference still exists, abort the operation. That is
1517 : * already implemented in the NO ACTION trigger, so just run it. (This
1518 : * recheck is only needed in the SET DEFAULT case, since CASCADE would
1519 : * remove such rows in case of a DELETE operation or would change the
1520 : * FK key values in case of an UPDATE, while SET NULL is certain to
1521 : * result in rows that satisfy the FK constraint.)
1522 : */
1523 88 : return ri_restrict(trigdata, true);
1524 : }
1525 : }
1526 :
1527 :
1528 : /*
1529 : * RI_FKey_pk_upd_check_required -
1530 : *
1531 : * Check if we really need to fire the RI trigger for an update or delete to a PK
1532 : * relation. This is called by the AFTER trigger queue manager to see if
1533 : * it can skip queuing an instance of an RI trigger. Returns true if the
1534 : * trigger must be fired, false if we can prove the constraint will still
1535 : * be satisfied.
1536 : *
1537 : * newslot will be NULL if this is called for a delete.
1538 : */
1539 : bool
1540 1533 : RI_FKey_pk_upd_check_required(Trigger *trigger, Relation pk_rel,
1541 : TupleTableSlot *oldslot, TupleTableSlot *newslot)
1542 : {
1543 : const RI_ConstraintInfo *riinfo;
1544 :
1545 1533 : riinfo = ri_FetchConstraintInfo(trigger, pk_rel, true);
1546 :
1547 : /*
1548 : * If any old key value is NULL, the row could not have been referenced by
1549 : * an FK row, so no check is needed.
1550 : */
1551 1533 : if (ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) != RI_KEYS_NONE_NULL)
1552 4 : return false;
1553 :
1554 : /* If all old and new key values are equal, no check is needed */
1555 1529 : if (newslot && ri_KeysEqual(pk_rel, oldslot, newslot, riinfo, true))
1556 288 : return false;
1557 :
1558 : /* Else we need to fire the trigger. */
1559 1241 : return true;
1560 : }
1561 :
1562 : /*
1563 : * RI_FKey_fk_upd_check_required -
1564 : *
1565 : * Check if we really need to fire the RI trigger for an update to an FK
1566 : * relation. This is called by the AFTER trigger queue manager to see if
1567 : * it can skip queuing an instance of an RI trigger. Returns true if the
1568 : * trigger must be fired, false if we can prove the constraint will still
1569 : * be satisfied.
1570 : */
1571 : bool
1572 668 : RI_FKey_fk_upd_check_required(Trigger *trigger, Relation fk_rel,
1573 : TupleTableSlot *oldslot, TupleTableSlot *newslot)
1574 : {
1575 : const RI_ConstraintInfo *riinfo;
1576 : int ri_nullcheck;
1577 :
1578 : /*
1579 : * AfterTriggerSaveEvent() handles things such that this function is never
1580 : * called for partitioned tables.
1581 : */
1582 : Assert(fk_rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE);
1583 :
1584 668 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1585 :
1586 668 : ri_nullcheck = ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false);
1587 :
1588 : /*
1589 : * If all new key values are NULL, the row satisfies the constraint, so no
1590 : * check is needed.
1591 : */
1592 668 : if (ri_nullcheck == RI_KEYS_ALL_NULL)
1593 84 : return false;
1594 :
1595 : /*
1596 : * If some new key values are NULL, the behavior depends on the match
1597 : * type.
1598 : */
1599 584 : else if (ri_nullcheck == RI_KEYS_SOME_NULL)
1600 : {
1601 20 : switch (riinfo->confmatchtype)
1602 : {
1603 16 : case FKCONSTR_MATCH_SIMPLE:
1604 :
1605 : /*
1606 : * If any new key value is NULL, the row must satisfy the
1607 : * constraint, so no check is needed.
1608 : */
1609 16 : return false;
1610 :
1611 0 : case FKCONSTR_MATCH_PARTIAL:
1612 :
1613 : /*
1614 : * Don't know, must run full check.
1615 : */
1616 0 : break;
1617 :
1618 4 : case FKCONSTR_MATCH_FULL:
1619 :
1620 : /*
1621 : * If some new key values are NULL, the row fails the
1622 : * constraint. We must not throw error here, because the row
1623 : * might get invalidated before the constraint is to be
1624 : * checked, but we should queue the event to apply the check
1625 : * later.
1626 : */
1627 4 : return true;
1628 : }
1629 : }
1630 :
1631 : /*
1632 : * Continues here for no new key values are NULL, or we couldn't decide
1633 : * yet.
1634 : */
1635 :
1636 : /*
1637 : * If the original row was inserted by our own transaction, we must fire
1638 : * the trigger whether or not the keys are equal. This is because our
1639 : * UPDATE will invalidate the INSERT so that the INSERT RI trigger will
1640 : * not do anything; so we had better do the UPDATE check. (We could skip
1641 : * this if we knew the INSERT trigger already fired, but there is no easy
1642 : * way to know that.)
1643 : */
1644 564 : if (slot_is_current_xact_tuple(oldslot))
1645 77 : return true;
1646 :
1647 : /* If all old and new key values are equal, no check is needed */
1648 487 : if (ri_KeysEqual(fk_rel, oldslot, newslot, riinfo, false))
1649 262 : return false;
1650 :
1651 : /* Else we need to fire the trigger. */
1652 225 : return true;
1653 : }
1654 :
1655 : /*
1656 : * RI_Initial_Check -
1657 : *
1658 : * Check an entire table for non-matching values using a single query.
1659 : * This is not a trigger procedure, but is called during ALTER TABLE
1660 : * ADD FOREIGN KEY to validate the initial table contents.
1661 : *
1662 : * We expect that the caller has made provision to prevent any problems
1663 : * caused by concurrent actions. This could be either by locking rel and
1664 : * pkrel at ShareRowExclusiveLock or higher, or by otherwise ensuring
1665 : * that triggers implementing the checks are already active.
1666 : * Hence, we do not need to lock individual rows for the check.
1667 : *
1668 : * If the check fails because the current user doesn't have permissions
1669 : * to read both tables, return false to let our caller know that they will
1670 : * need to do something else to check the constraint.
1671 : */
1672 : bool
1673 769 : RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
1674 : {
1675 : const RI_ConstraintInfo *riinfo;
1676 : StringInfoData querybuf;
1677 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
1678 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1679 : char pkattname[MAX_QUOTED_NAME_LEN + 3];
1680 : char fkattname[MAX_QUOTED_NAME_LEN + 3];
1681 : RangeTblEntry *rte;
1682 : RTEPermissionInfo *pk_perminfo;
1683 : RTEPermissionInfo *fk_perminfo;
1684 769 : List *rtes = NIL;
1685 769 : List *perminfos = NIL;
1686 : const char *sep;
1687 : const char *fk_only;
1688 : const char *pk_only;
1689 : int save_nestlevel;
1690 : char workmembuf[32];
1691 : int spi_result;
1692 : SPIPlanPtr qplan;
1693 :
1694 769 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1695 :
1696 : /*
1697 : * Check to make sure current user has enough permissions to do the test
1698 : * query. (If not, caller can fall back to the trigger method, which
1699 : * works because it changes user IDs on the fly.)
1700 : *
1701 : * XXX are there any other show-stopper conditions to check?
1702 : */
1703 769 : pk_perminfo = makeNode(RTEPermissionInfo);
1704 769 : pk_perminfo->relid = RelationGetRelid(pk_rel);
1705 769 : pk_perminfo->requiredPerms = ACL_SELECT;
1706 769 : perminfos = lappend(perminfos, pk_perminfo);
1707 769 : rte = makeNode(RangeTblEntry);
1708 769 : rte->rtekind = RTE_RELATION;
1709 769 : rte->relid = RelationGetRelid(pk_rel);
1710 769 : rte->relkind = pk_rel->rd_rel->relkind;
1711 769 : rte->rellockmode = AccessShareLock;
1712 769 : rte->perminfoindex = list_length(perminfos);
1713 769 : rtes = lappend(rtes, rte);
1714 :
1715 769 : fk_perminfo = makeNode(RTEPermissionInfo);
1716 769 : fk_perminfo->relid = RelationGetRelid(fk_rel);
1717 769 : fk_perminfo->requiredPerms = ACL_SELECT;
1718 769 : perminfos = lappend(perminfos, fk_perminfo);
1719 769 : rte = makeNode(RangeTblEntry);
1720 769 : rte->rtekind = RTE_RELATION;
1721 769 : rte->relid = RelationGetRelid(fk_rel);
1722 769 : rte->relkind = fk_rel->rd_rel->relkind;
1723 769 : rte->rellockmode = AccessShareLock;
1724 769 : rte->perminfoindex = list_length(perminfos);
1725 769 : rtes = lappend(rtes, rte);
1726 :
1727 1807 : for (int i = 0; i < riinfo->nkeys; i++)
1728 : {
1729 : int attno;
1730 :
1731 1038 : attno = riinfo->pk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
1732 1038 : pk_perminfo->selectedCols = bms_add_member(pk_perminfo->selectedCols, attno);
1733 :
1734 1038 : attno = riinfo->fk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
1735 1038 : fk_perminfo->selectedCols = bms_add_member(fk_perminfo->selectedCols, attno);
1736 : }
1737 :
1738 769 : if (!ExecCheckPermissions(rtes, perminfos, false))
1739 8 : return false;
1740 :
1741 : /*
1742 : * Also punt if RLS is enabled on either table unless this role has the
1743 : * bypassrls right or is the table owner of the table(s) involved which
1744 : * have RLS enabled.
1745 : */
1746 761 : if (!has_bypassrls_privilege(GetUserId()) &&
1747 0 : ((pk_rel->rd_rel->relrowsecurity &&
1748 0 : !object_ownercheck(RelationRelationId, RelationGetRelid(pk_rel),
1749 0 : GetUserId())) ||
1750 0 : (fk_rel->rd_rel->relrowsecurity &&
1751 0 : !object_ownercheck(RelationRelationId, RelationGetRelid(fk_rel),
1752 : GetUserId()))))
1753 0 : return false;
1754 :
1755 : /*----------
1756 : * The query string built is:
1757 : * SELECT fk.keycols FROM [ONLY] relname fk
1758 : * LEFT OUTER JOIN [ONLY] pkrelname pk
1759 : * ON (pk.pkkeycol1=fk.keycol1 [AND ...])
1760 : * WHERE pk.pkkeycol1 IS NULL AND
1761 : * For MATCH SIMPLE:
1762 : * (fk.keycol1 IS NOT NULL [AND ...])
1763 : * For MATCH FULL:
1764 : * (fk.keycol1 IS NOT NULL [OR ...])
1765 : *
1766 : * We attach COLLATE clauses to the operators when comparing columns
1767 : * that have different collations.
1768 : *----------
1769 : */
1770 761 : initStringInfo(&querybuf);
1771 761 : appendStringInfoString(&querybuf, "SELECT ");
1772 761 : sep = "";
1773 1783 : for (int i = 0; i < riinfo->nkeys; i++)
1774 : {
1775 1022 : quoteOneName(fkattname,
1776 1022 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1777 1022 : appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
1778 1022 : sep = ", ";
1779 : }
1780 :
1781 761 : quoteRelationName(pkrelname, pk_rel);
1782 761 : quoteRelationName(fkrelname, fk_rel);
1783 1522 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1784 761 : "" : "ONLY ";
1785 1522 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1786 761 : "" : "ONLY ";
1787 761 : appendStringInfo(&querybuf,
1788 : " FROM %s%s fk LEFT OUTER JOIN %s%s pk ON",
1789 : fk_only, fkrelname, pk_only, pkrelname);
1790 :
1791 761 : strcpy(pkattname, "pk.");
1792 761 : strcpy(fkattname, "fk.");
1793 761 : sep = "(";
1794 1783 : for (int i = 0; i < riinfo->nkeys; i++)
1795 : {
1796 1022 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1797 1022 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1798 1022 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
1799 1022 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
1800 :
1801 1022 : quoteOneName(pkattname + 3,
1802 1022 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
1803 1022 : quoteOneName(fkattname + 3,
1804 1022 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1805 1022 : ri_GenerateQual(&querybuf, sep,
1806 : pkattname, pk_type,
1807 1022 : riinfo->pf_eq_oprs[i],
1808 : fkattname, fk_type);
1809 1022 : if (pk_coll != fk_coll)
1810 8 : ri_GenerateQualCollation(&querybuf, pk_coll);
1811 1022 : sep = "AND";
1812 : }
1813 :
1814 : /*
1815 : * It's sufficient to test any one pk attribute for null to detect a join
1816 : * failure.
1817 : */
1818 761 : quoteOneName(pkattname, RIAttName(pk_rel, riinfo->pk_attnums[0]));
1819 761 : appendStringInfo(&querybuf, ") WHERE pk.%s IS NULL AND (", pkattname);
1820 :
1821 761 : sep = "";
1822 1783 : for (int i = 0; i < riinfo->nkeys; i++)
1823 : {
1824 1022 : quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
1825 1022 : appendStringInfo(&querybuf,
1826 : "%sfk.%s IS NOT NULL",
1827 : sep, fkattname);
1828 1022 : switch (riinfo->confmatchtype)
1829 : {
1830 948 : case FKCONSTR_MATCH_SIMPLE:
1831 948 : sep = " AND ";
1832 948 : break;
1833 74 : case FKCONSTR_MATCH_FULL:
1834 74 : sep = " OR ";
1835 74 : break;
1836 : }
1837 : }
1838 761 : appendStringInfoChar(&querybuf, ')');
1839 :
1840 : /*
1841 : * Temporarily increase work_mem so that the check query can be executed
1842 : * more efficiently. It seems okay to do this because the query is simple
1843 : * enough to not use a multiple of work_mem, and one typically would not
1844 : * have many large foreign-key validations happening concurrently. So
1845 : * this seems to meet the criteria for being considered a "maintenance"
1846 : * operation, and accordingly we use maintenance_work_mem. However, we
1847 : * must also set hash_mem_multiplier to 1, since it is surely not okay to
1848 : * let that get applied to the maintenance_work_mem value.
1849 : *
1850 : * We use the equivalent of a function SET option to allow the setting to
1851 : * persist for exactly the duration of the check query. guc.c also takes
1852 : * care of undoing the setting on error.
1853 : */
1854 761 : save_nestlevel = NewGUCNestLevel();
1855 :
1856 761 : snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
1857 761 : (void) set_config_option("work_mem", workmembuf,
1858 : PGC_USERSET, PGC_S_SESSION,
1859 : GUC_ACTION_SAVE, true, 0, false);
1860 761 : (void) set_config_option("hash_mem_multiplier", "1",
1861 : PGC_USERSET, PGC_S_SESSION,
1862 : GUC_ACTION_SAVE, true, 0, false);
1863 :
1864 761 : SPI_connect();
1865 :
1866 : /*
1867 : * Generate the plan. We don't need to cache it, and there are no
1868 : * arguments to the plan.
1869 : */
1870 761 : qplan = SPI_prepare(querybuf.data, 0, NULL);
1871 :
1872 761 : if (qplan == NULL)
1873 0 : elog(ERROR, "SPI_prepare returned %s for %s",
1874 : SPI_result_code_string(SPI_result), querybuf.data);
1875 :
1876 : /*
1877 : * Run the plan. For safety we force a current snapshot to be used. (In
1878 : * transaction-snapshot mode, this arguably violates transaction isolation
1879 : * rules, but we really haven't got much choice.) We don't need to
1880 : * register the snapshot, because SPI_execute_snapshot will see to it. We
1881 : * need at most one tuple returned, so pass limit = 1.
1882 : */
1883 761 : spi_result = SPI_execute_snapshot(qplan,
1884 : NULL, NULL,
1885 : GetLatestSnapshot(),
1886 : InvalidSnapshot,
1887 : true, false, 1);
1888 :
1889 : /* Check result */
1890 761 : if (spi_result != SPI_OK_SELECT)
1891 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
1892 :
1893 : /* Did we find a tuple violating the constraint? */
1894 761 : if (SPI_processed > 0)
1895 : {
1896 : TupleTableSlot *slot;
1897 59 : HeapTuple tuple = SPI_tuptable->vals[0];
1898 59 : TupleDesc tupdesc = SPI_tuptable->tupdesc;
1899 : RI_ConstraintInfo fake_riinfo;
1900 :
1901 59 : slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
1902 :
1903 59 : heap_deform_tuple(tuple, tupdesc,
1904 : slot->tts_values, slot->tts_isnull);
1905 59 : ExecStoreVirtualTuple(slot);
1906 :
1907 : /*
1908 : * The columns to look at in the result tuple are 1..N, not whatever
1909 : * they are in the fk_rel. Hack up riinfo so that the subroutines
1910 : * called here will behave properly.
1911 : *
1912 : * In addition to this, we have to pass the correct tupdesc to
1913 : * ri_ReportViolation, overriding its normal habit of using the pk_rel
1914 : * or fk_rel's tupdesc.
1915 : */
1916 59 : memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
1917 134 : for (int i = 0; i < fake_riinfo.nkeys; i++)
1918 75 : fake_riinfo.fk_attnums[i] = i + 1;
1919 :
1920 : /*
1921 : * If it's MATCH FULL, and there are any nulls in the FK keys,
1922 : * complain about that rather than the lack of a match. MATCH FULL
1923 : * disallows partially-null FK rows.
1924 : */
1925 79 : if (fake_riinfo.confmatchtype == FKCONSTR_MATCH_FULL &&
1926 20 : ri_NullCheck(tupdesc, slot, &fake_riinfo, false) != RI_KEYS_NONE_NULL)
1927 8 : ereport(ERROR,
1928 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
1929 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
1930 : RelationGetRelationName(fk_rel),
1931 : NameStr(fake_riinfo.conname)),
1932 : errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
1933 : errtableconstraint(fk_rel,
1934 : NameStr(fake_riinfo.conname))));
1935 :
1936 : /*
1937 : * We tell ri_ReportViolation we were doing the RI_PLAN_CHECK_LOOKUPPK
1938 : * query, which isn't true, but will cause it to use
1939 : * fake_riinfo.fk_attnums as we need.
1940 : */
1941 51 : ri_ReportViolation(&fake_riinfo,
1942 : pk_rel, fk_rel,
1943 : slot, tupdesc,
1944 : RI_PLAN_CHECK_LOOKUPPK, false, false);
1945 :
1946 : ExecDropSingleTupleTableSlot(slot);
1947 : }
1948 :
1949 702 : if (SPI_finish() != SPI_OK_FINISH)
1950 0 : elog(ERROR, "SPI_finish failed");
1951 :
1952 : /*
1953 : * Restore work_mem and hash_mem_multiplier.
1954 : */
1955 702 : AtEOXact_GUC(true, save_nestlevel);
1956 :
1957 702 : return true;
1958 : }
1959 :
1960 : /*
1961 : * RI_PartitionRemove_Check -
1962 : *
1963 : * Verify no referencing values exist, when a partition is detached on
1964 : * the referenced side of a foreign key constraint.
1965 : */
1966 : void
1967 65 : RI_PartitionRemove_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
1968 : {
1969 : const RI_ConstraintInfo *riinfo;
1970 : StringInfoData querybuf;
1971 : char *constraintDef;
1972 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
1973 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1974 : char pkattname[MAX_QUOTED_NAME_LEN + 3];
1975 : char fkattname[MAX_QUOTED_NAME_LEN + 3];
1976 : const char *sep;
1977 : const char *fk_only;
1978 : int save_nestlevel;
1979 : char workmembuf[32];
1980 : int spi_result;
1981 : SPIPlanPtr qplan;
1982 : int i;
1983 :
1984 65 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1985 :
1986 : /*
1987 : * We don't check permissions before displaying the error message, on the
1988 : * assumption that the user detaching the partition must have enough
1989 : * privileges to examine the table contents anyhow.
1990 : */
1991 :
1992 : /*----------
1993 : * The query string built is:
1994 : * SELECT fk.keycols FROM [ONLY] relname fk
1995 : * JOIN pkrelname pk
1996 : * ON (pk.pkkeycol1=fk.keycol1 [AND ...])
1997 : * WHERE (<partition constraint>) AND
1998 : * For MATCH SIMPLE:
1999 : * (fk.keycol1 IS NOT NULL [AND ...])
2000 : * For MATCH FULL:
2001 : * (fk.keycol1 IS NOT NULL [OR ...])
2002 : *
2003 : * We attach COLLATE clauses to the operators when comparing columns
2004 : * that have different collations.
2005 : *----------
2006 : */
2007 65 : initStringInfo(&querybuf);
2008 65 : appendStringInfoString(&querybuf, "SELECT ");
2009 65 : sep = "";
2010 130 : for (i = 0; i < riinfo->nkeys; i++)
2011 : {
2012 65 : quoteOneName(fkattname,
2013 65 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
2014 65 : appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
2015 65 : sep = ", ";
2016 : }
2017 :
2018 65 : quoteRelationName(pkrelname, pk_rel);
2019 65 : quoteRelationName(fkrelname, fk_rel);
2020 130 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
2021 65 : "" : "ONLY ";
2022 65 : appendStringInfo(&querybuf,
2023 : " FROM %s%s fk JOIN %s pk ON",
2024 : fk_only, fkrelname, pkrelname);
2025 65 : strcpy(pkattname, "pk.");
2026 65 : strcpy(fkattname, "fk.");
2027 65 : sep = "(";
2028 130 : for (i = 0; i < riinfo->nkeys; i++)
2029 : {
2030 65 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
2031 65 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
2032 65 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
2033 65 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
2034 :
2035 65 : quoteOneName(pkattname + 3,
2036 65 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
2037 65 : quoteOneName(fkattname + 3,
2038 65 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
2039 65 : ri_GenerateQual(&querybuf, sep,
2040 : pkattname, pk_type,
2041 65 : riinfo->pf_eq_oprs[i],
2042 : fkattname, fk_type);
2043 65 : if (pk_coll != fk_coll)
2044 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
2045 65 : sep = "AND";
2046 : }
2047 :
2048 : /*
2049 : * Start the WHERE clause with the partition constraint (except if this is
2050 : * the default partition and there's no other partition, because the
2051 : * partition constraint is the empty string in that case.)
2052 : */
2053 65 : constraintDef = pg_get_partconstrdef_string(RelationGetRelid(pk_rel), "pk");
2054 65 : if (constraintDef && constraintDef[0] != '\0')
2055 65 : appendStringInfo(&querybuf, ") WHERE %s AND (",
2056 : constraintDef);
2057 : else
2058 0 : appendStringInfoString(&querybuf, ") WHERE (");
2059 :
2060 65 : sep = "";
2061 130 : for (i = 0; i < riinfo->nkeys; i++)
2062 : {
2063 65 : quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
2064 65 : appendStringInfo(&querybuf,
2065 : "%sfk.%s IS NOT NULL",
2066 : sep, fkattname);
2067 65 : switch (riinfo->confmatchtype)
2068 : {
2069 65 : case FKCONSTR_MATCH_SIMPLE:
2070 65 : sep = " AND ";
2071 65 : break;
2072 0 : case FKCONSTR_MATCH_FULL:
2073 0 : sep = " OR ";
2074 0 : break;
2075 : }
2076 : }
2077 65 : appendStringInfoChar(&querybuf, ')');
2078 :
2079 : /*
2080 : * Temporarily increase work_mem so that the check query can be executed
2081 : * more efficiently. It seems okay to do this because the query is simple
2082 : * enough to not use a multiple of work_mem, and one typically would not
2083 : * have many large foreign-key validations happening concurrently. So
2084 : * this seems to meet the criteria for being considered a "maintenance"
2085 : * operation, and accordingly we use maintenance_work_mem. However, we
2086 : * must also set hash_mem_multiplier to 1, since it is surely not okay to
2087 : * let that get applied to the maintenance_work_mem value.
2088 : *
2089 : * We use the equivalent of a function SET option to allow the setting to
2090 : * persist for exactly the duration of the check query. guc.c also takes
2091 : * care of undoing the setting on error.
2092 : */
2093 65 : save_nestlevel = NewGUCNestLevel();
2094 :
2095 65 : snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
2096 65 : (void) set_config_option("work_mem", workmembuf,
2097 : PGC_USERSET, PGC_S_SESSION,
2098 : GUC_ACTION_SAVE, true, 0, false);
2099 65 : (void) set_config_option("hash_mem_multiplier", "1",
2100 : PGC_USERSET, PGC_S_SESSION,
2101 : GUC_ACTION_SAVE, true, 0, false);
2102 :
2103 65 : SPI_connect();
2104 :
2105 : /*
2106 : * Generate the plan. We don't need to cache it, and there are no
2107 : * arguments to the plan.
2108 : */
2109 65 : qplan = SPI_prepare(querybuf.data, 0, NULL);
2110 :
2111 65 : if (qplan == NULL)
2112 0 : elog(ERROR, "SPI_prepare returned %s for %s",
2113 : SPI_result_code_string(SPI_result), querybuf.data);
2114 :
2115 : /*
2116 : * Run the plan. For safety we force a current snapshot to be used. (In
2117 : * transaction-snapshot mode, this arguably violates transaction isolation
2118 : * rules, but we really haven't got much choice.) We don't need to
2119 : * register the snapshot, because SPI_execute_snapshot will see to it. We
2120 : * need at most one tuple returned, so pass limit = 1.
2121 : */
2122 65 : spi_result = SPI_execute_snapshot(qplan,
2123 : NULL, NULL,
2124 : GetLatestSnapshot(),
2125 : InvalidSnapshot,
2126 : true, false, 1);
2127 :
2128 : /* Check result */
2129 65 : if (spi_result != SPI_OK_SELECT)
2130 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
2131 :
2132 : /* Did we find a tuple that would violate the constraint? */
2133 65 : if (SPI_processed > 0)
2134 : {
2135 : TupleTableSlot *slot;
2136 22 : HeapTuple tuple = SPI_tuptable->vals[0];
2137 22 : TupleDesc tupdesc = SPI_tuptable->tupdesc;
2138 : RI_ConstraintInfo fake_riinfo;
2139 :
2140 22 : slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
2141 :
2142 22 : heap_deform_tuple(tuple, tupdesc,
2143 : slot->tts_values, slot->tts_isnull);
2144 22 : ExecStoreVirtualTuple(slot);
2145 :
2146 : /*
2147 : * The columns to look at in the result tuple are 1..N, not whatever
2148 : * they are in the fk_rel. Hack up riinfo so that ri_ReportViolation
2149 : * will behave properly.
2150 : *
2151 : * In addition to this, we have to pass the correct tupdesc to
2152 : * ri_ReportViolation, overriding its normal habit of using the pk_rel
2153 : * or fk_rel's tupdesc.
2154 : */
2155 22 : memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
2156 44 : for (i = 0; i < fake_riinfo.nkeys; i++)
2157 22 : fake_riinfo.pk_attnums[i] = i + 1;
2158 :
2159 22 : ri_ReportViolation(&fake_riinfo, pk_rel, fk_rel,
2160 : slot, tupdesc, 0, false, true);
2161 : }
2162 :
2163 43 : if (SPI_finish() != SPI_OK_FINISH)
2164 0 : elog(ERROR, "SPI_finish failed");
2165 :
2166 : /*
2167 : * Restore work_mem and hash_mem_multiplier.
2168 : */
2169 43 : AtEOXact_GUC(true, save_nestlevel);
2170 43 : }
2171 :
2172 :
2173 : /* ----------
2174 : * Local functions below
2175 : * ----------
2176 : */
2177 :
2178 :
2179 : /*
2180 : * quoteOneName --- safely quote a single SQL name
2181 : *
2182 : * buffer must be MAX_QUOTED_NAME_LEN long (includes room for \0)
2183 : */
2184 : static void
2185 13152 : quoteOneName(char *buffer, const char *name)
2186 : {
2187 : /* Rather than trying to be smart, just always quote it. */
2188 13152 : *buffer++ = '"';
2189 81295 : while (*name)
2190 : {
2191 68143 : if (*name == '"')
2192 0 : *buffer++ = '"';
2193 68143 : *buffer++ = *name++;
2194 : }
2195 13152 : *buffer++ = '"';
2196 13152 : *buffer = '\0';
2197 13152 : }
2198 :
2199 : /*
2200 : * quoteRelationName --- safely quote a fully qualified relation name
2201 : *
2202 : * buffer must be MAX_QUOTED_REL_NAME_LEN long (includes room for \0)
2203 : */
2204 : static void
2205 2905 : quoteRelationName(char *buffer, Relation rel)
2206 : {
2207 2905 : quoteOneName(buffer, get_namespace_name(RelationGetNamespace(rel)));
2208 2905 : buffer += strlen(buffer);
2209 2905 : *buffer++ = '.';
2210 2905 : quoteOneName(buffer, RelationGetRelationName(rel));
2211 2905 : }
2212 :
2213 : /*
2214 : * ri_GenerateQual --- generate a WHERE clause equating two variables
2215 : *
2216 : * This basically appends " sep leftop op rightop" to buf, adding casts
2217 : * and schema qualification as needed to ensure that the parser will select
2218 : * the operator we specify. leftop and rightop should be parenthesized
2219 : * if they aren't variables or parameters.
2220 : */
2221 : static void
2222 3134 : ri_GenerateQual(StringInfo buf,
2223 : const char *sep,
2224 : const char *leftop, Oid leftoptype,
2225 : Oid opoid,
2226 : const char *rightop, Oid rightoptype)
2227 : {
2228 3134 : appendStringInfo(buf, " %s ", sep);
2229 3134 : generate_operator_clause(buf, leftop, leftoptype, opoid,
2230 : rightop, rightoptype);
2231 3134 : }
2232 :
2233 : /*
2234 : * ri_GenerateQualCollation --- add a COLLATE spec to a WHERE clause
2235 : *
2236 : * We only have to use this function when directly comparing the referencing
2237 : * and referenced columns, if they are of different collations; else the
2238 : * parser will fail to resolve the collation to use. We don't need to use
2239 : * this function for RI queries that compare a variable to a $n parameter.
2240 : * Since parameter symbols always have default collation, the effect will be
2241 : * to use the variable's collation.
2242 : *
2243 : * Note that we require that the collations of the referencing and the
2244 : * referenced column have the same notion of equality: Either they have to
2245 : * both be deterministic or else they both have to be the same. (See also
2246 : * ATAddForeignKeyConstraint().)
2247 : */
2248 : static void
2249 8 : ri_GenerateQualCollation(StringInfo buf, Oid collation)
2250 : {
2251 : HeapTuple tp;
2252 : Form_pg_collation colltup;
2253 : char *collname;
2254 : char onename[MAX_QUOTED_NAME_LEN];
2255 :
2256 : /* Nothing to do if it's a noncollatable data type */
2257 8 : if (!OidIsValid(collation))
2258 0 : return;
2259 :
2260 8 : tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
2261 8 : if (!HeapTupleIsValid(tp))
2262 0 : elog(ERROR, "cache lookup failed for collation %u", collation);
2263 8 : colltup = (Form_pg_collation) GETSTRUCT(tp);
2264 8 : collname = NameStr(colltup->collname);
2265 :
2266 : /*
2267 : * We qualify the name always, for simplicity and to ensure the query is
2268 : * not search-path-dependent.
2269 : */
2270 8 : quoteOneName(onename, get_namespace_name(colltup->collnamespace));
2271 8 : appendStringInfo(buf, " COLLATE %s", onename);
2272 8 : quoteOneName(onename, collname);
2273 8 : appendStringInfo(buf, ".%s", onename);
2274 :
2275 8 : ReleaseSysCache(tp);
2276 : }
2277 :
2278 : /* ----------
2279 : * ri_BuildQueryKey -
2280 : *
2281 : * Construct a hashtable key for a prepared SPI plan of an FK constraint.
2282 : *
2283 : * key: output argument, *key is filled in based on the other arguments
2284 : * riinfo: info derived from pg_constraint entry
2285 : * constr_queryno: an internal number identifying the query type
2286 : * (see RI_PLAN_XXX constants at head of file)
2287 : * ----------
2288 : */
2289 : static void
2290 2475 : ri_BuildQueryKey(RI_QueryKey *key, const RI_ConstraintInfo *riinfo,
2291 : int32 constr_queryno)
2292 : {
2293 : /*
2294 : * Inherited constraints with a common ancestor can share ri_query_cache
2295 : * entries for all query types except RI_PLAN_CHECK_LOOKUPPK_FROM_PK.
2296 : * Except in that case, the query processes the other table involved in
2297 : * the FK constraint (i.e., not the table on which the trigger has been
2298 : * fired), and so it will be the same for all members of the inheritance
2299 : * tree. So we may use the root constraint's OID in the hash key, rather
2300 : * than the constraint's own OID. This avoids creating duplicate SPI
2301 : * plans, saving lots of work and memory when there are many partitions
2302 : * with similar FK constraints.
2303 : *
2304 : * (Note that we must still have a separate RI_ConstraintInfo for each
2305 : * constraint, because partitions can have different column orders,
2306 : * resulting in different pk_attnums[] or fk_attnums[] array contents.)
2307 : *
2308 : * We assume struct RI_QueryKey contains no padding bytes, else we'd need
2309 : * to use memset to clear them.
2310 : */
2311 2475 : if (constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK)
2312 1952 : key->constr_id = riinfo->constraint_root_id;
2313 : else
2314 523 : key->constr_id = riinfo->constraint_id;
2315 2475 : key->constr_queryno = constr_queryno;
2316 2475 : }
2317 :
2318 : /*
2319 : * Check that RI trigger function was called in expected context
2320 : */
2321 : static void
2322 607555 : ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname, int tgkind)
2323 : {
2324 607555 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
2325 :
2326 607555 : if (!CALLED_AS_TRIGGER(fcinfo))
2327 0 : ereport(ERROR,
2328 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2329 : errmsg("function \"%s\" was not called by trigger manager", funcname)));
2330 :
2331 : /*
2332 : * Check proper event
2333 : */
2334 607555 : if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
2335 607555 : !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
2336 0 : ereport(ERROR,
2337 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2338 : errmsg("function \"%s\" must be fired AFTER ROW", funcname)));
2339 :
2340 607555 : switch (tgkind)
2341 : {
2342 606149 : case RI_TRIGTYPE_INSERT:
2343 606149 : if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
2344 0 : ereport(ERROR,
2345 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2346 : errmsg("function \"%s\" must be fired for INSERT", funcname)));
2347 606149 : break;
2348 866 : case RI_TRIGTYPE_UPDATE:
2349 866 : if (!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
2350 0 : ereport(ERROR,
2351 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2352 : errmsg("function \"%s\" must be fired for UPDATE", funcname)));
2353 866 : break;
2354 540 : case RI_TRIGTYPE_DELETE:
2355 540 : if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
2356 0 : ereport(ERROR,
2357 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
2358 : errmsg("function \"%s\" must be fired for DELETE", funcname)));
2359 540 : break;
2360 : }
2361 607555 : }
2362 :
2363 :
2364 : /*
2365 : * Fetch the RI_ConstraintInfo struct for the trigger's FK constraint.
2366 : */
2367 : static RI_ConstraintInfo *
2368 610678 : ri_FetchConstraintInfo(Trigger *trigger, Relation trig_rel, bool rel_is_pk)
2369 : {
2370 610678 : Oid constraintOid = trigger->tgconstraint;
2371 : RI_ConstraintInfo *riinfo;
2372 :
2373 : /*
2374 : * Check that the FK constraint's OID is available; it might not be if
2375 : * we've been invoked via an ordinary trigger or an old-style "constraint
2376 : * trigger".
2377 : */
2378 610678 : if (!OidIsValid(constraintOid))
2379 0 : ereport(ERROR,
2380 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
2381 : errmsg("no pg_constraint entry for trigger \"%s\" on table \"%s\"",
2382 : trigger->tgname, RelationGetRelationName(trig_rel)),
2383 : errhint("Remove this referential integrity trigger and its mates, then do ALTER TABLE ADD CONSTRAINT.")));
2384 :
2385 : /* Find or create a hashtable entry for the constraint */
2386 610678 : riinfo = ri_LoadConstraintInfo(constraintOid);
2387 :
2388 : /* Do some easy cross-checks against the trigger call data */
2389 610678 : if (rel_is_pk)
2390 : {
2391 2733 : if (riinfo->fk_relid != trigger->tgconstrrelid ||
2392 2733 : riinfo->pk_relid != RelationGetRelid(trig_rel))
2393 0 : elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
2394 : trigger->tgname, RelationGetRelationName(trig_rel));
2395 : }
2396 : else
2397 : {
2398 607945 : if (riinfo->fk_relid != RelationGetRelid(trig_rel) ||
2399 607945 : riinfo->pk_relid != trigger->tgconstrrelid)
2400 0 : elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
2401 : trigger->tgname, RelationGetRelationName(trig_rel));
2402 : }
2403 :
2404 610678 : if (riinfo->confmatchtype != FKCONSTR_MATCH_FULL &&
2405 610365 : riinfo->confmatchtype != FKCONSTR_MATCH_PARTIAL &&
2406 610365 : riinfo->confmatchtype != FKCONSTR_MATCH_SIMPLE)
2407 0 : elog(ERROR, "unrecognized confmatchtype: %d",
2408 : riinfo->confmatchtype);
2409 :
2410 610678 : if (riinfo->confmatchtype == FKCONSTR_MATCH_PARTIAL)
2411 0 : ereport(ERROR,
2412 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2413 : errmsg("MATCH PARTIAL not yet implemented")));
2414 :
2415 610678 : return riinfo;
2416 : }
2417 :
2418 : /*
2419 : * Fetch or create the RI_ConstraintInfo struct for an FK constraint.
2420 : */
2421 : static RI_ConstraintInfo *
2422 613364 : ri_LoadConstraintInfo(Oid constraintOid)
2423 : {
2424 : RI_ConstraintInfo *riinfo;
2425 : bool found;
2426 : HeapTuple tup;
2427 : Form_pg_constraint conForm;
2428 :
2429 : /*
2430 : * On the first call initialize the hashtable
2431 : */
2432 613364 : if (!ri_constraint_cache)
2433 264 : ri_InitHashTables();
2434 :
2435 : /*
2436 : * Find or create a hash entry. If we find a valid one, just return it.
2437 : */
2438 613364 : riinfo = (RI_ConstraintInfo *) hash_search(ri_constraint_cache,
2439 : &constraintOid,
2440 : HASH_ENTER, &found);
2441 613364 : if (!found)
2442 2498 : riinfo->valid = false;
2443 610866 : else if (riinfo->valid)
2444 610598 : return riinfo;
2445 :
2446 : /*
2447 : * Fetch the pg_constraint row so we can fill in the entry.
2448 : */
2449 2766 : tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
2450 2766 : if (!HeapTupleIsValid(tup)) /* should not happen */
2451 0 : elog(ERROR, "cache lookup failed for constraint %u", constraintOid);
2452 2766 : conForm = (Form_pg_constraint) GETSTRUCT(tup);
2453 :
2454 2766 : if (conForm->contype != CONSTRAINT_FOREIGN) /* should not happen */
2455 0 : elog(ERROR, "constraint %u is not a foreign key constraint",
2456 : constraintOid);
2457 :
2458 : /* And extract data */
2459 : Assert(riinfo->constraint_id == constraintOid);
2460 2766 : if (OidIsValid(conForm->conparentid))
2461 964 : riinfo->constraint_root_id =
2462 964 : get_ri_constraint_root(conForm->conparentid);
2463 : else
2464 1802 : riinfo->constraint_root_id = constraintOid;
2465 2766 : riinfo->oidHashValue = GetSysCacheHashValue1(CONSTROID,
2466 : ObjectIdGetDatum(constraintOid));
2467 2766 : riinfo->rootHashValue = GetSysCacheHashValue1(CONSTROID,
2468 : ObjectIdGetDatum(riinfo->constraint_root_id));
2469 2766 : memcpy(&riinfo->conname, &conForm->conname, sizeof(NameData));
2470 2766 : riinfo->pk_relid = conForm->confrelid;
2471 2766 : riinfo->fk_relid = conForm->conrelid;
2472 2766 : riinfo->confupdtype = conForm->confupdtype;
2473 2766 : riinfo->confdeltype = conForm->confdeltype;
2474 2766 : riinfo->confmatchtype = conForm->confmatchtype;
2475 2766 : riinfo->hasperiod = conForm->conperiod;
2476 :
2477 2766 : DeconstructFkConstraintRow(tup,
2478 : &riinfo->nkeys,
2479 2766 : riinfo->fk_attnums,
2480 2766 : riinfo->pk_attnums,
2481 2766 : riinfo->pf_eq_oprs,
2482 2766 : riinfo->pp_eq_oprs,
2483 2766 : riinfo->ff_eq_oprs,
2484 : &riinfo->ndelsetcols,
2485 2766 : riinfo->confdelsetcols);
2486 :
2487 : /*
2488 : * For temporal FKs, get the operators and functions we need. We ask the
2489 : * opclass of the PK element for these. This all gets cached (as does the
2490 : * generated plan), so there's no performance issue.
2491 : */
2492 2766 : if (riinfo->hasperiod)
2493 : {
2494 141 : Oid opclass = get_index_column_opclass(conForm->conindid, riinfo->nkeys);
2495 :
2496 141 : FindFKPeriodOpers(opclass,
2497 : &riinfo->period_contained_by_oper,
2498 : &riinfo->agged_period_contained_by_oper,
2499 : &riinfo->period_intersect_oper);
2500 : }
2501 :
2502 : /* Metadata used by fast path. */
2503 2766 : riinfo->conindid = conForm->conindid;
2504 2766 : riinfo->pk_is_partitioned =
2505 2766 : (get_rel_relkind(riinfo->pk_relid) == RELKIND_PARTITIONED_TABLE);
2506 :
2507 2766 : ReleaseSysCache(tup);
2508 :
2509 : /*
2510 : * For efficient processing of invalidation messages below, we keep a
2511 : * doubly-linked count list of all currently valid entries.
2512 : */
2513 2766 : dclist_push_tail(&ri_constraint_cache_valid_list, &riinfo->valid_link);
2514 :
2515 2766 : riinfo->valid = true;
2516 :
2517 2766 : riinfo->fpmeta = NULL;
2518 :
2519 2766 : return riinfo;
2520 : }
2521 :
2522 : /*
2523 : * get_ri_constraint_root
2524 : * Returns the OID of the constraint's root parent
2525 : */
2526 : static Oid
2527 964 : get_ri_constraint_root(Oid constrOid)
2528 : {
2529 : for (;;)
2530 232 : {
2531 : HeapTuple tuple;
2532 : Oid constrParentOid;
2533 :
2534 1196 : tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid));
2535 1196 : if (!HeapTupleIsValid(tuple))
2536 0 : elog(ERROR, "cache lookup failed for constraint %u", constrOid);
2537 1196 : constrParentOid = ((Form_pg_constraint) GETSTRUCT(tuple))->conparentid;
2538 1196 : ReleaseSysCache(tuple);
2539 1196 : if (!OidIsValid(constrParentOid))
2540 964 : break; /* we reached the root constraint */
2541 232 : constrOid = constrParentOid;
2542 : }
2543 964 : return constrOid;
2544 : }
2545 :
2546 : /*
2547 : * Callback for pg_constraint inval events
2548 : *
2549 : * While most syscache callbacks just flush all their entries, pg_constraint
2550 : * gets enough update traffic that it's probably worth being smarter.
2551 : * Invalidate any ri_constraint_cache entry associated with the syscache
2552 : * entry with the specified hash value, or all entries if hashvalue == 0.
2553 : *
2554 : * Note: at the time a cache invalidation message is processed there may be
2555 : * active references to the cache. Because of this we never remove entries
2556 : * from the cache, but only mark them invalid, which is harmless to active
2557 : * uses. (Any query using an entry should hold a lock sufficient to keep that
2558 : * data from changing under it --- but we may get cache flushes anyway.)
2559 : */
2560 : static void
2561 57809 : InvalidateConstraintCacheCallBack(Datum arg, SysCacheIdentifier cacheid,
2562 : uint32 hashvalue)
2563 : {
2564 : dlist_mutable_iter iter;
2565 :
2566 : Assert(ri_constraint_cache != NULL);
2567 :
2568 : /*
2569 : * If the list of currently valid entries gets excessively large, we mark
2570 : * them all invalid so we can empty the list. This arrangement avoids
2571 : * O(N^2) behavior in situations where a session touches many foreign keys
2572 : * and also does many ALTER TABLEs, such as a restore from pg_dump.
2573 : */
2574 57809 : if (dclist_count(&ri_constraint_cache_valid_list) > 1000)
2575 0 : hashvalue = 0; /* pretend it's a cache reset */
2576 :
2577 248191 : dclist_foreach_modify(iter, &ri_constraint_cache_valid_list)
2578 : {
2579 190382 : RI_ConstraintInfo *riinfo = dclist_container(RI_ConstraintInfo,
2580 : valid_link, iter.cur);
2581 :
2582 : /*
2583 : * We must invalidate not only entries directly matching the given
2584 : * hash value, but also child entries, in case the invalidation
2585 : * affects a root constraint.
2586 : */
2587 190382 : if (hashvalue == 0 ||
2588 190339 : riinfo->oidHashValue == hashvalue ||
2589 188589 : riinfo->rootHashValue == hashvalue)
2590 : {
2591 2009 : riinfo->valid = false;
2592 2009 : if (riinfo->fpmeta)
2593 : {
2594 664 : pfree(riinfo->fpmeta);
2595 664 : riinfo->fpmeta = NULL;
2596 : }
2597 : /* Remove invalidated entries from the list, too */
2598 2009 : dclist_delete_from(&ri_constraint_cache_valid_list, iter.cur);
2599 : }
2600 : }
2601 57809 : }
2602 :
2603 :
2604 : /*
2605 : * Prepare execution plan for a query to enforce an RI restriction
2606 : */
2607 : static SPIPlanPtr
2608 1162 : ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
2609 : RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel)
2610 : {
2611 : SPIPlanPtr qplan;
2612 : Relation query_rel;
2613 : Oid save_userid;
2614 : int save_sec_context;
2615 :
2616 : /*
2617 : * Use the query type code to determine whether the query is run against
2618 : * the PK or FK table; we'll do the check as that table's owner
2619 : */
2620 1162 : if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
2621 609 : query_rel = pk_rel;
2622 : else
2623 553 : query_rel = fk_rel;
2624 :
2625 : /* Switch to proper UID to perform check as */
2626 1162 : GetUserIdAndSecContext(&save_userid, &save_sec_context);
2627 1162 : SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
2628 : save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
2629 : SECURITY_NOFORCE_RLS);
2630 :
2631 : /* Create the plan */
2632 1162 : qplan = SPI_prepare(querystr, nargs, argtypes);
2633 :
2634 1162 : if (qplan == NULL)
2635 0 : elog(ERROR, "SPI_prepare returned %s for %s", SPI_result_code_string(SPI_result), querystr);
2636 :
2637 : /* Restore UID and security context */
2638 1162 : SetUserIdAndSecContext(save_userid, save_sec_context);
2639 :
2640 : /* Save the plan */
2641 1162 : SPI_keepplan(qplan);
2642 1162 : ri_HashPreparedPlan(qkey, qplan);
2643 :
2644 1162 : return qplan;
2645 : }
2646 :
2647 : /*
2648 : * Perform a query to enforce an RI restriction
2649 : */
2650 : static bool
2651 2475 : ri_PerformCheck(const RI_ConstraintInfo *riinfo,
2652 : RI_QueryKey *qkey, SPIPlanPtr qplan,
2653 : Relation fk_rel, Relation pk_rel,
2654 : TupleTableSlot *oldslot, TupleTableSlot *newslot,
2655 : bool is_restrict,
2656 : bool detectNewRows, int expect_OK)
2657 : {
2658 : Relation query_rel,
2659 : source_rel;
2660 : bool source_is_pk;
2661 : Snapshot test_snapshot;
2662 : Snapshot crosscheck_snapshot;
2663 : int limit;
2664 : int spi_result;
2665 : Oid save_userid;
2666 : int save_sec_context;
2667 : Datum vals[RI_MAX_NUMKEYS * 2];
2668 : char nulls[RI_MAX_NUMKEYS * 2];
2669 :
2670 : /*
2671 : * Use the query type code to determine whether the query is run against
2672 : * the PK or FK table; we'll do the check as that table's owner
2673 : */
2674 2475 : if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
2675 1313 : query_rel = pk_rel;
2676 : else
2677 1162 : query_rel = fk_rel;
2678 :
2679 : /*
2680 : * The values for the query are taken from the table on which the trigger
2681 : * is called - it is normally the other one with respect to query_rel. An
2682 : * exception is ri_Check_Pk_Match(), which uses the PK table for both (and
2683 : * sets queryno to RI_PLAN_CHECK_LOOKUPPK_FROM_PK). We might eventually
2684 : * need some less klugy way to determine this.
2685 : */
2686 2475 : if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK)
2687 : {
2688 790 : source_rel = fk_rel;
2689 790 : source_is_pk = false;
2690 : }
2691 : else
2692 : {
2693 1685 : source_rel = pk_rel;
2694 1685 : source_is_pk = true;
2695 : }
2696 :
2697 : /* Extract the parameters to be passed into the query */
2698 2475 : if (newslot)
2699 : {
2700 934 : ri_ExtractValues(source_rel, newslot, riinfo, source_is_pk,
2701 : vals, nulls);
2702 934 : if (oldslot)
2703 144 : ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
2704 144 : vals + riinfo->nkeys, nulls + riinfo->nkeys);
2705 : }
2706 : else
2707 : {
2708 1541 : ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
2709 : vals, nulls);
2710 : }
2711 :
2712 : /*
2713 : * In READ COMMITTED mode, we just need to use an up-to-date regular
2714 : * snapshot, and we will see all rows that could be interesting. But in
2715 : * transaction-snapshot mode, we can't change the transaction snapshot. If
2716 : * the caller passes detectNewRows == false then it's okay to do the query
2717 : * with the transaction snapshot; otherwise we use a current snapshot, and
2718 : * tell the executor to error out if it finds any rows under the current
2719 : * snapshot that wouldn't be visible per the transaction snapshot. Note
2720 : * that SPI_execute_snapshot will register the snapshots, so we don't need
2721 : * to bother here.
2722 : */
2723 2475 : if (IsolationUsesXactSnapshot() && detectNewRows)
2724 : {
2725 36 : CommandCounterIncrement(); /* be sure all my own work is visible */
2726 36 : test_snapshot = GetLatestSnapshot();
2727 36 : crosscheck_snapshot = GetTransactionSnapshot();
2728 : }
2729 : else
2730 : {
2731 : /* the default SPI behavior is okay */
2732 2439 : test_snapshot = InvalidSnapshot;
2733 2439 : crosscheck_snapshot = InvalidSnapshot;
2734 : }
2735 :
2736 : /*
2737 : * If this is a select query (e.g., for a 'no action' or 'restrict'
2738 : * trigger), we only need to see if there is a single row in the table,
2739 : * matching the key. Otherwise, limit = 0 - because we want the query to
2740 : * affect ALL the matching rows.
2741 : */
2742 2475 : limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
2743 :
2744 : /* Switch to proper UID to perform check as */
2745 2475 : GetUserIdAndSecContext(&save_userid, &save_sec_context);
2746 2475 : SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
2747 : save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
2748 : SECURITY_NOFORCE_RLS);
2749 :
2750 : /*
2751 : * Finally we can run the query.
2752 : *
2753 : * Set fire_triggers to false to ensure that AFTER triggers are queued in
2754 : * the outer query's after-trigger context and fire after all RI updates
2755 : * on the same row are complete, rather than immediately.
2756 : */
2757 2475 : spi_result = SPI_execute_snapshot(qplan,
2758 : vals, nulls,
2759 : test_snapshot, crosscheck_snapshot,
2760 : false, false, limit);
2761 :
2762 : /* Restore UID and security context */
2763 2465 : SetUserIdAndSecContext(save_userid, save_sec_context);
2764 :
2765 : /* Check result */
2766 2465 : if (spi_result < 0)
2767 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
2768 :
2769 2465 : if (expect_OK >= 0 && spi_result != expect_OK)
2770 0 : ereport(ERROR,
2771 : (errcode(ERRCODE_INTERNAL_ERROR),
2772 : errmsg("referential integrity query on \"%s\" from constraint \"%s\" on \"%s\" gave unexpected result",
2773 : RelationGetRelationName(pk_rel),
2774 : NameStr(riinfo->conname),
2775 : RelationGetRelationName(fk_rel)),
2776 : errhint("This is most likely due to a rule having rewritten the query.")));
2777 :
2778 : /* XXX wouldn't it be clearer to do this part at the caller? */
2779 2465 : if (qkey->constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK &&
2780 1529 : expect_OK == SPI_OK_SELECT &&
2781 1529 : (SPI_processed == 0) == (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK))
2782 462 : ri_ReportViolation(riinfo,
2783 : pk_rel, fk_rel,
2784 : newslot ? newslot : oldslot,
2785 : NULL,
2786 : qkey->constr_queryno, is_restrict, false);
2787 :
2788 2003 : return SPI_processed != 0;
2789 : }
2790 :
2791 : /*
2792 : * ri_FastPathCheck
2793 : * Perform per row FK existence check via direct index probe,
2794 : * bypassing SPI.
2795 : *
2796 : * If no matching PK row exists, report the violation via ri_ReportViolation(),
2797 : * otherwise, the function returns normally.
2798 : *
2799 : * Note: This is only used by the ALTER TABLE validation path. Other paths use
2800 : * ri_FastPathBatchAdd().
2801 : */
2802 : static void
2803 440 : ri_FastPathCheck(RI_ConstraintInfo *riinfo,
2804 : Relation fk_rel, TupleTableSlot *newslot)
2805 : {
2806 : Relation pk_rel;
2807 : Relation idx_rel;
2808 : IndexScanDesc scandesc;
2809 : TupleTableSlot *slot;
2810 : Datum pk_vals[INDEX_MAX_KEYS];
2811 : char pk_nulls[INDEX_MAX_KEYS];
2812 : ScanKeyData skey[INDEX_MAX_KEYS];
2813 440 : bool found = false;
2814 : Oid saved_userid;
2815 : int saved_sec_context;
2816 : Snapshot snapshot;
2817 :
2818 : /*
2819 : * Advance the command counter so the snapshot sees the effects of prior
2820 : * triggers in this statement. Mirrors what the SPI path does in
2821 : * ri_PerformCheck().
2822 : */
2823 440 : CommandCounterIncrement();
2824 440 : snapshot = RegisterSnapshot(GetTransactionSnapshot());
2825 :
2826 440 : pk_rel = table_open(riinfo->pk_relid, RowShareLock);
2827 440 : idx_rel = index_open(riinfo->conindid, AccessShareLock);
2828 :
2829 440 : slot = table_slot_create(pk_rel, NULL);
2830 440 : scandesc = index_beginscan(pk_rel, idx_rel,
2831 : snapshot, NULL,
2832 : riinfo->nkeys, 0,
2833 : SO_NONE);
2834 :
2835 440 : GetUserIdAndSecContext(&saved_userid, &saved_sec_context);
2836 440 : SetUserIdAndSecContext(RelationGetForm(pk_rel)->relowner,
2837 : saved_sec_context |
2838 : SECURITY_LOCAL_USERID_CHANGE |
2839 : SECURITY_NOFORCE_RLS);
2840 440 : ri_CheckPermissions(pk_rel);
2841 :
2842 440 : if (riinfo->fpmeta == NULL)
2843 : {
2844 : /* Reload to ensure it's valid. */
2845 12 : riinfo = ri_LoadConstraintInfo(riinfo->constraint_id);
2846 12 : ri_populate_fastpath_metadata(riinfo, fk_rel, idx_rel);
2847 : }
2848 : Assert(riinfo->fpmeta);
2849 440 : ri_ExtractValues(fk_rel, newslot, riinfo, false, pk_vals, pk_nulls);
2850 440 : build_index_scankeys(riinfo, idx_rel, pk_vals, pk_nulls, skey);
2851 440 : found = ri_FastPathProbeOne(pk_rel, idx_rel, scandesc, slot,
2852 : snapshot, riinfo, skey, riinfo->nkeys);
2853 440 : SetUserIdAndSecContext(saved_userid, saved_sec_context);
2854 440 : index_endscan(scandesc);
2855 440 : ExecDropSingleTupleTableSlot(slot);
2856 440 : UnregisterSnapshot(snapshot);
2857 :
2858 440 : if (!found)
2859 11 : ri_ReportViolation(riinfo, pk_rel, fk_rel,
2860 : newslot, NULL,
2861 : RI_PLAN_CHECK_LOOKUPPK, false, false);
2862 :
2863 429 : index_close(idx_rel, NoLock);
2864 429 : table_close(pk_rel, NoLock);
2865 429 : }
2866 :
2867 : /*
2868 : * ri_FastPathBatchAdd
2869 : * Buffer a FK row for batched probing.
2870 : *
2871 : * Adds the row to the batch buffer. When the buffer is full, flushes all
2872 : * buffered rows by probing the PK index. Any violation is reported
2873 : * immediately during the flush via ri_ReportViolation (which does not return).
2874 : *
2875 : * Uses the per-batch cache (RI_FastPathEntry) to avoid per-row relation
2876 : * open/close, slot creation, etc.
2877 : *
2878 : * The batch is also flushed at end of trigger-firing cycle via
2879 : * ri_FastPathEndBatch().
2880 : */
2881 : static void
2882 605223 : ri_FastPathBatchAdd(RI_ConstraintInfo *riinfo,
2883 : Relation fk_rel, TupleTableSlot *newslot)
2884 : {
2885 605223 : RI_FastPathEntry *fpentry = ri_FastPathGetEntry(riinfo, fk_rel);
2886 :
2887 : /*
2888 : * If this entry is already being flushed, a cast function or an operator
2889 : * invoked during the flush has re-entered with DML on the same FK. Fall
2890 : * back to the per-row path rather than touching the batch array, which is
2891 : * mid-flush.
2892 : */
2893 605223 : if (unlikely(fpentry->flushing))
2894 : {
2895 256 : ri_FastPathCheck(riinfo, fk_rel, newslot);
2896 256 : return;
2897 : }
2898 :
2899 : /*
2900 : * Buffer the row. A full batch is flushed below and re-entry is handled
2901 : * above, so there is always room here; the bounds check just guards the
2902 : * array write.
2903 : */
2904 604967 : if (fpentry->batch_count < RI_FASTPATH_BATCH_SIZE)
2905 : {
2906 604967 : MemoryContext oldcxt = MemoryContextSwitchTo(fpentry->flush_cxt);
2907 :
2908 1209934 : fpentry->batch[fpentry->batch_count] =
2909 604967 : ExecCopySlotHeapTuple(newslot);
2910 604967 : fpentry->batch_count++;
2911 604967 : MemoryContextSwitchTo(oldcxt);
2912 : }
2913 : else
2914 0 : elog(ERROR, "RI fast-path batch unexpectedly full");
2915 :
2916 : /* Flush as soon as the batch is full. */
2917 604967 : if (fpentry->batch_count == RI_FASTPATH_BATCH_SIZE)
2918 9412 : ri_FastPathBatchFlush(fpentry, fk_rel, riinfo);
2919 : }
2920 :
2921 : /*
2922 : * ri_FastPathBatchFlush
2923 : * Flush all buffered FK rows by probing the PK index.
2924 : *
2925 : * Dispatches to ri_FastPathFlushArray() for single-column FKs
2926 : * (using SK_SEARCHARRAY) or ri_FastPathFlushLoop() for multi-column
2927 : * FKs (per-row probing). Violations are reported immediately via
2928 : * ri_ReportViolation(), which does not return.
2929 : */
2930 : static void
2931 11131 : ri_FastPathBatchFlush(RI_FastPathEntry *fpentry, Relation fk_rel,
2932 : RI_ConstraintInfo *riinfo)
2933 : {
2934 11131 : Relation pk_rel = fpentry->pk_rel;
2935 11131 : Relation idx_rel = fpentry->idx_rel;
2936 11131 : TupleTableSlot *fk_slot = fpentry->fk_slot;
2937 : Snapshot snapshot;
2938 : IndexScanDesc scandesc;
2939 : Oid saved_userid;
2940 : int saved_sec_context;
2941 : MemoryContext oldcxt;
2942 : int violation_index;
2943 :
2944 11131 : if (fpentry->batch_count == 0)
2945 0 : return;
2946 :
2947 : /*
2948 : * CCI and security context switch are done once for the entire batch.
2949 : * Per-row CCI is unnecessary because by the time a flush runs, all AFTER
2950 : * triggers for the buffered rows have already fired (trigger invocations
2951 : * strictly alternate per row), so a single CCI advances past all their
2952 : * effects. Per-row security context switch is unnecessary because each
2953 : * row's probe runs entirely as the PK table owner, same as the SPI path
2954 : * -- the only difference is that the SPI path sets and restores the
2955 : * context per row whereas we do it once around the whole batch.
2956 : */
2957 11131 : CommandCounterIncrement();
2958 11131 : snapshot = RegisterSnapshot(GetTransactionSnapshot());
2959 :
2960 : /*
2961 : * build_index_scankeys() may palloc cast results for cross-type FKs. Use
2962 : * the entry's short-lived flush context so these don't accumulate across
2963 : * batches.
2964 : */
2965 11131 : oldcxt = MemoryContextSwitchTo(fpentry->flush_cxt);
2966 :
2967 11131 : scandesc = index_beginscan(pk_rel, idx_rel, snapshot, NULL,
2968 : riinfo->nkeys, 0, SO_NONE);
2969 :
2970 11131 : GetUserIdAndSecContext(&saved_userid, &saved_sec_context);
2971 11131 : SetUserIdAndSecContext(RelationGetForm(pk_rel)->relowner,
2972 : saved_sec_context |
2973 : SECURITY_LOCAL_USERID_CHANGE |
2974 : SECURITY_NOFORCE_RLS);
2975 :
2976 : /*
2977 : * Check that the current user has permission to access pk_rel. Done here
2978 : * rather than at entry creation so that permission changes between
2979 : * flushes are respected, matching the per-row behavior of the SPI path,
2980 : * albeit checked once per flush rather than once per row, like in
2981 : * ri_FastPathCheck().
2982 : */
2983 11131 : ri_CheckPermissions(pk_rel);
2984 :
2985 11127 : if (riinfo->fpmeta == NULL)
2986 : {
2987 : /* Reload to ensure it's valid. */
2988 955 : riinfo = ri_LoadConstraintInfo(riinfo->constraint_id);
2989 955 : ri_populate_fastpath_metadata(riinfo, fk_rel, idx_rel);
2990 : }
2991 : Assert(riinfo->fpmeta);
2992 :
2993 : /*
2994 : * The probe runs user-defined cast and equality functions. Set the
2995 : * flushing flag around it so a re-entrant ri_FastPathBatchAdd on this
2996 : * entry takes the per-row path, and clear it even on error so the entry
2997 : * is reusable if the error is caught by a savepoint.
2998 : */
2999 : Assert(!fpentry->flushing);
3000 11127 : fpentry->flushing = true;
3001 11127 : PG_TRY();
3002 : {
3003 : /* Skip array overhead for single-row batches. */
3004 11127 : if (riinfo->nkeys == 1 && fpentry->batch_count > 1)
3005 9561 : violation_index = ri_FastPathFlushArray(fpentry, fk_slot, riinfo,
3006 : fk_rel, snapshot, scandesc);
3007 : else
3008 1566 : violation_index = ri_FastPathFlushLoop(fpentry, fk_slot, riinfo,
3009 : fk_rel, snapshot, scandesc);
3010 : }
3011 7 : PG_FINALLY();
3012 : {
3013 11127 : fpentry->flushing = false;
3014 11127 : fpentry->batch_count = 0;
3015 : }
3016 11127 : PG_END_TRY();
3017 :
3018 11120 : SetUserIdAndSecContext(saved_userid, saved_sec_context);
3019 11120 : UnregisterSnapshot(snapshot);
3020 11120 : index_endscan(scandesc);
3021 :
3022 11120 : if (violation_index >= 0)
3023 : {
3024 287 : ExecStoreHeapTuple(fpentry->batch[violation_index], fk_slot, false);
3025 287 : ri_ReportViolation(riinfo, pk_rel, fk_rel,
3026 : fk_slot, NULL,
3027 : RI_PLAN_CHECK_LOOKUPPK, false, false);
3028 : }
3029 :
3030 10833 : MemoryContextReset(fpentry->flush_cxt);
3031 10833 : MemoryContextSwitchTo(oldcxt);
3032 : }
3033 :
3034 : /*
3035 : * ri_FastPathFlushLoop
3036 : * Multi-column fallback: probe the index once per buffered row.
3037 : *
3038 : * Used for composite foreign keys where SK_SEARCHARRAY does not
3039 : * apply, and also for single-row batches of single-column FKs where
3040 : * the array overhead is not worth it.
3041 : *
3042 : * Returns the index of the first violating row in the batch array, or -1 if
3043 : * all rows are valid.
3044 : */
3045 : static int
3046 1566 : ri_FastPathFlushLoop(RI_FastPathEntry *fpentry, TupleTableSlot *fk_slot,
3047 : const RI_ConstraintInfo *riinfo, Relation fk_rel,
3048 : Snapshot snapshot, IndexScanDesc scandesc)
3049 : {
3050 1566 : Relation pk_rel = fpentry->pk_rel;
3051 1566 : Relation idx_rel = fpentry->idx_rel;
3052 1566 : TupleTableSlot *pk_slot = fpentry->pk_slot;
3053 : Datum pk_vals[INDEX_MAX_KEYS];
3054 : char pk_nulls[INDEX_MAX_KEYS];
3055 : ScanKeyData skey[INDEX_MAX_KEYS];
3056 1566 : bool found = true;
3057 :
3058 3238 : for (int i = 0; i < fpentry->batch_count; i++)
3059 : {
3060 1958 : ExecStoreHeapTuple(fpentry->batch[i], fk_slot, false);
3061 1958 : ri_ExtractValues(fk_rel, fk_slot, riinfo, false, pk_vals, pk_nulls);
3062 1958 : build_index_scankeys(riinfo, idx_rel, pk_vals, pk_nulls, skey);
3063 :
3064 1958 : found = ri_FastPathProbeOne(pk_rel, idx_rel, scandesc, pk_slot,
3065 1958 : snapshot, riinfo, skey, riinfo->nkeys);
3066 :
3067 : /* Report first unmatched row */
3068 1951 : if (!found)
3069 279 : return i;
3070 : }
3071 :
3072 : /* All pass. */
3073 1280 : return -1;
3074 : }
3075 :
3076 : /*
3077 : * ri_FastPathFlushArray
3078 : * Single-column fast path using SK_SEARCHARRAY.
3079 : *
3080 : * Builds an array of FK values and does one index scan with
3081 : * SK_SEARCHARRAY. The index AM sorts and deduplicates the array
3082 : * internally, then walks matching leaf pages in order. Each
3083 : * matched PK tuple is locked and rechecked as before; a matched[]
3084 : * bitmap tracks which batch items were satisfied.
3085 : *
3086 : * Returns the index of the first violating row in the batch array, or -1 if
3087 : * all rows are valid.
3088 : */
3089 : static int
3090 9561 : ri_FastPathFlushArray(RI_FastPathEntry *fpentry, TupleTableSlot *fk_slot,
3091 : const RI_ConstraintInfo *riinfo, Relation fk_rel,
3092 : Snapshot snapshot, IndexScanDesc scandesc)
3093 : {
3094 9561 : FastPathMeta *fpmeta = riinfo->fpmeta;
3095 9561 : Relation pk_rel = fpentry->pk_rel;
3096 9561 : Relation idx_rel = fpentry->idx_rel;
3097 9561 : TupleTableSlot *pk_slot = fpentry->pk_slot;
3098 : Datum search_vals[RI_FASTPATH_BATCH_SIZE];
3099 : bool matched[RI_FASTPATH_BATCH_SIZE];
3100 9561 : int nvals = fpentry->batch_count;
3101 : Datum pk_vals[INDEX_MAX_KEYS];
3102 : char pk_nulls[INDEX_MAX_KEYS];
3103 : ScanKeyData skey[1];
3104 : FmgrInfo *cast_func_finfo;
3105 : FmgrInfo *eq_opr_finfo;
3106 : Oid elem_type;
3107 : int16 elem_len;
3108 : bool elem_byval;
3109 : char elem_align;
3110 : ArrayType *arr;
3111 :
3112 : Assert(fpmeta);
3113 :
3114 9561 : memset(matched, 0, nvals * sizeof(bool));
3115 :
3116 : /*
3117 : * Extract FK values, casting to the operator's expected input type if
3118 : * needed (e.g. int8 FK -> int4 for int48eq).
3119 : */
3120 9561 : cast_func_finfo = &fpmeta->cast_func_finfo[0];
3121 9561 : eq_opr_finfo = &fpmeta->eq_opr_finfo[0];
3122 612554 : for (int i = 0; i < nvals; i++)
3123 : {
3124 602993 : ExecStoreHeapTuple(fpentry->batch[i], fk_slot, false);
3125 602993 : ri_ExtractValues(fk_rel, fk_slot, riinfo, false, pk_vals, pk_nulls);
3126 :
3127 : /* Cast if needed (e.g. int8 FK -> numeric PK) */
3128 602993 : if (OidIsValid(cast_func_finfo->fn_oid))
3129 256 : search_vals[i] = FunctionCall3(cast_func_finfo,
3130 : pk_vals[0],
3131 : Int32GetDatum(-1),
3132 : BoolGetDatum(false));
3133 : else
3134 602737 : search_vals[i] = pk_vals[0];
3135 : }
3136 :
3137 : /*
3138 : * Array element type must match the operator's right-hand input type,
3139 : * which is what the index comparison expects on the search side.
3140 : * ri_populate_fastpath_metadata() stores exactly this via
3141 : * get_op_opfamily_properties(), which returns the operator's right-hand
3142 : * type as the subtype for cross-type operators (e.g. int8 for int48eq)
3143 : * and the common type for same-type operators.
3144 : */
3145 9561 : elem_type = fpmeta->subtypes[0];
3146 : Assert(OidIsValid(elem_type));
3147 9561 : get_typlenbyvalalign(elem_type, &elem_len, &elem_byval, &elem_align);
3148 :
3149 9561 : arr = construct_array(search_vals, nvals,
3150 : elem_type, elem_len, elem_byval, elem_align);
3151 :
3152 : /*
3153 : * Build scan key with SK_SEARCHARRAY. The index AM code will internally
3154 : * sort and deduplicate, then walk leaf pages in order.
3155 : *
3156 : * PK indexes are always btree, which supports SK_SEARCHARRAY.
3157 : *
3158 : * This path handles single-column FKs only, so index_attnos[0] == 1.
3159 : */
3160 : Assert(idx_rel->rd_indam->amsearcharray);
3161 : Assert(fpmeta->index_attnos[0] == 1);
3162 9561 : ScanKeyEntryInitialize(&skey[0],
3163 : SK_SEARCHARRAY,
3164 9561 : fpmeta->index_attnos[0],
3165 9561 : fpmeta->strats[0],
3166 : fpmeta->subtypes[0],
3167 9561 : idx_rel->rd_indcollation[fpmeta->index_attnos[0] - 1],
3168 : fpmeta->regops[0],
3169 : PointerGetDatum(arr));
3170 :
3171 9561 : index_rescan(scandesc, skey, 1, NULL, 0);
3172 :
3173 : /*
3174 : * Walk all matches. The index AM returns them in index order. For each
3175 : * match, find which batch item(s) it satisfies.
3176 : */
3177 420880 : while (index_getnext_slot(scandesc, ForwardScanDirection, pk_slot))
3178 : {
3179 : Datum found_val;
3180 : bool found_null;
3181 : bool concurrently_updated;
3182 : ScanKeyData recheck_skey[1];
3183 :
3184 411319 : if (!ri_LockPKTuple(pk_rel, pk_slot, snapshot, &concurrently_updated))
3185 0 : continue;
3186 :
3187 : /* Extract the PK value from the matched and locked tuple */
3188 411319 : found_val = slot_getattr(pk_slot, riinfo->pk_attnums[0], &found_null);
3189 : Assert(!found_null);
3190 :
3191 411319 : if (concurrently_updated)
3192 : {
3193 : /*
3194 : * Build a single-key scankey for recheck. We need the actual PK
3195 : * value that was found, not the FK search value.
3196 : */
3197 0 : ScanKeyEntryInitialize(&recheck_skey[0], 0, 1,
3198 0 : fpmeta->strats[0],
3199 : fpmeta->subtypes[0],
3200 0 : idx_rel->rd_indcollation[0],
3201 : fpmeta->regops[0],
3202 : found_val);
3203 0 : if (!recheck_matched_pk_tuple(idx_rel, recheck_skey, 1, pk_slot))
3204 0 : continue;
3205 : }
3206 :
3207 : /*
3208 : * Linear scan to mark all batch items matching this PK value.
3209 : * O(batch_size) per match, O(batch_size^2) worst case -- fine for the
3210 : * current batch size of 64.
3211 : */
3212 26708584 : for (int i = 0; i < nvals; i++)
3213 : {
3214 39747360 : if (!matched[i] &&
3215 13450095 : DatumGetBool(FunctionCall2Coll(eq_opr_finfo,
3216 13450095 : idx_rel->rd_indcollation[0],
3217 : found_val,
3218 : search_vals[i])))
3219 602981 : matched[i] = true;
3220 : }
3221 : }
3222 :
3223 : /* Report first unmatched row */
3224 612538 : for (int i = 0; i < nvals; i++)
3225 602985 : if (!matched[i])
3226 8 : return i;
3227 :
3228 : /* All pass. */
3229 9553 : return -1;
3230 : }
3231 :
3232 : /*
3233 : * ri_FastPathProbeOne
3234 : * Probe the PK index for one set of scan keys, lock the matching
3235 : * tuple
3236 : *
3237 : * Returns true if a matching PK row was found, locked, and (if
3238 : * applicable) visible to the transaction snapshot.
3239 : */
3240 : static bool
3241 2398 : ri_FastPathProbeOne(Relation pk_rel, Relation idx_rel,
3242 : IndexScanDesc scandesc, TupleTableSlot *slot,
3243 : Snapshot snapshot, const RI_ConstraintInfo *riinfo,
3244 : ScanKeyData *skey, int nkeys)
3245 : {
3246 2398 : bool found = false;
3247 :
3248 2398 : index_rescan(scandesc, skey, nkeys, NULL, 0);
3249 :
3250 2398 : if (index_getnext_slot(scandesc, ForwardScanDirection, slot))
3251 : {
3252 : bool concurrently_updated;
3253 :
3254 2110 : if (ri_LockPKTuple(pk_rel, slot, snapshot,
3255 : &concurrently_updated))
3256 : {
3257 2102 : if (concurrently_updated)
3258 2 : found = recheck_matched_pk_tuple(idx_rel, skey, nkeys, slot);
3259 : else
3260 2100 : found = true;
3261 : }
3262 : }
3263 :
3264 2391 : return found;
3265 : }
3266 :
3267 : /*
3268 : * ri_LockPKTuple
3269 : * Lock a PK tuple found by the fast-path index scan.
3270 : *
3271 : * Calls table_tuple_lock() directly with handling specific to RI checks.
3272 : * Returns true if the tuple was successfully locked.
3273 : *
3274 : * Sets *concurrently_updated to true if the locked tuple was reached
3275 : * by following an update chain (tmfd.traversed), indicating the caller
3276 : * should recheck the key.
3277 : */
3278 : static bool
3279 413429 : ri_LockPKTuple(Relation pk_rel, TupleTableSlot *slot, Snapshot snap,
3280 : bool *concurrently_updated)
3281 : {
3282 : TM_FailureData tmfd;
3283 : TM_Result result;
3284 413429 : int lockflags = TUPLE_LOCK_FLAG_LOCK_UPDATE_IN_PROGRESS;
3285 :
3286 413429 : *concurrently_updated = false;
3287 :
3288 413429 : if (!IsolationUsesXactSnapshot())
3289 413407 : lockflags |= TUPLE_LOCK_FLAG_FIND_LAST_VERSION;
3290 :
3291 413429 : result = table_tuple_lock(pk_rel, &slot->tts_tid, snap,
3292 : slot, GetCurrentCommandId(false),
3293 : LockTupleKeyShare, LockWaitBlock,
3294 : lockflags, &tmfd);
3295 :
3296 413426 : switch (result)
3297 : {
3298 413421 : case TM_Ok:
3299 413421 : if (tmfd.traversed)
3300 2 : *concurrently_updated = true;
3301 413421 : return true;
3302 :
3303 4 : case TM_Deleted:
3304 4 : if (IsolationUsesXactSnapshot())
3305 3 : ereport(ERROR,
3306 : (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
3307 : errmsg("could not serialize access due to concurrent delete")));
3308 1 : return false;
3309 :
3310 1 : case TM_Updated:
3311 1 : if (IsolationUsesXactSnapshot())
3312 1 : ereport(ERROR,
3313 : (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
3314 : errmsg("could not serialize access due to concurrent update")));
3315 :
3316 : /*
3317 : * In READ COMMITTED, FIND_LAST_VERSION should have chased the
3318 : * chain and returned TM_Ok. Getting here means something
3319 : * unexpected -- fall through to error.
3320 : */
3321 0 : elog(ERROR, "unexpected table_tuple_lock status: %u", result);
3322 : break;
3323 :
3324 0 : case TM_SelfModified:
3325 :
3326 : /*
3327 : * The current command or a later command in this transaction
3328 : * modified the PK row. This shouldn't normally happen during an
3329 : * FK check (we're not modifying pk_rel), but handle it safely by
3330 : * treating the tuple as not found.
3331 : */
3332 0 : return false;
3333 :
3334 0 : case TM_Invisible:
3335 0 : elog(ERROR, "attempted to lock invisible tuple");
3336 : break;
3337 :
3338 0 : default:
3339 0 : elog(ERROR, "unrecognized table_tuple_lock status: %u", result);
3340 : break;
3341 : }
3342 :
3343 : return false; /* keep compiler quiet */
3344 : }
3345 :
3346 : static bool
3347 606197 : ri_fastpath_is_applicable(const RI_ConstraintInfo *riinfo)
3348 : {
3349 : /*
3350 : * Partitioned referenced tables are skipped for simplicity, since they
3351 : * require routing the probe through the correct partition using
3352 : * PartitionDirectory.
3353 : */
3354 606197 : if (riinfo->pk_is_partitioned)
3355 639 : return false;
3356 :
3357 : /*
3358 : * Temporal foreign keys use range overlap and containment semantics (&&,
3359 : * <@, range_agg()) that inherently involve aggregation and multiple-row
3360 : * reasoning, so they stay on the SPI path.
3361 : */
3362 605558 : if (riinfo->hasperiod)
3363 151 : return false;
3364 :
3365 605407 : return true;
3366 : }
3367 :
3368 : /*
3369 : * ri_CheckPermissions
3370 : * Check that the current user has permissions to look into the schema of
3371 : * and SELECT from 'query_rel'
3372 : */
3373 : static void
3374 11571 : ri_CheckPermissions(Relation query_rel)
3375 : {
3376 : AclResult aclresult;
3377 :
3378 : /* USAGE on schema. */
3379 11571 : aclresult = object_aclcheck(NamespaceRelationId,
3380 11571 : RelationGetNamespace(query_rel),
3381 : GetUserId(), ACL_USAGE);
3382 11571 : if (aclresult != ACLCHECK_OK)
3383 0 : aclcheck_error(aclresult, OBJECT_SCHEMA,
3384 0 : get_namespace_name(RelationGetNamespace(query_rel)));
3385 :
3386 : /* SELECT on relation. */
3387 11571 : aclresult = pg_class_aclcheck(RelationGetRelid(query_rel), GetUserId(),
3388 : ACL_SELECT);
3389 11571 : if (aclresult != ACLCHECK_OK)
3390 4 : aclcheck_error(aclresult, OBJECT_TABLE,
3391 4 : RelationGetRelationName(query_rel));
3392 11567 : }
3393 :
3394 : /*
3395 : * recheck_matched_pk_tuple
3396 : * After following an update chain (tmfd.traversed), verify that
3397 : * the locked PK tuple still matches the original search keys.
3398 : *
3399 : * A non-key update (e.g. changing a non-PK column) creates a new tuple version
3400 : * that we've now locked, but the key is unchanged -- that's fine. A key
3401 : * update means the value we were looking for is gone, so we should treat it as
3402 : * not found.
3403 : */
3404 : static bool
3405 2 : recheck_matched_pk_tuple(Relation idxrel, ScanKeyData *skeys, int nkeys,
3406 : TupleTableSlot *new_slot)
3407 : {
3408 : /*
3409 : * TODO: BuildIndexInfo does a syscache lookup + palloc on every call.
3410 : * This only fires on the concurrent-update path (tmfd.traversed), which
3411 : * should be rare, so the cost is acceptable for now. If profiling shows
3412 : * otherwise, cache the IndexInfo in FastPathMeta.
3413 : */
3414 2 : IndexInfo *indexInfo = BuildIndexInfo(idxrel);
3415 : Datum values[INDEX_MAX_KEYS];
3416 : bool isnull[INDEX_MAX_KEYS];
3417 2 : bool matched = true;
3418 :
3419 : /* PK indexes never have these. */
3420 : Assert(indexInfo->ii_Expressions == NIL &&
3421 : indexInfo->ii_ExclusionOps == NULL);
3422 :
3423 : /* Form the index values and isnull flags given the table tuple. */
3424 : Assert(nkeys == indexInfo->ii_NumIndexKeyAttrs);
3425 2 : FormIndexDatum(indexInfo, new_slot, NULL, values, isnull);
3426 3 : for (int i = 0; i < nkeys; i++)
3427 : {
3428 2 : ScanKeyData *skey = &skeys[i];
3429 :
3430 : /* A PK column can never be set to NULL. */
3431 : Assert(!isnull[i]);
3432 2 : if (!DatumGetBool(FunctionCall2Coll(&skey->sk_func,
3433 : skey->sk_collation,
3434 : values[i],
3435 : skey->sk_argument)))
3436 : {
3437 1 : matched = false;
3438 1 : break;
3439 : }
3440 : }
3441 :
3442 2 : return matched;
3443 : }
3444 :
3445 : /*
3446 : * build_index_scankeys
3447 : * Build ScanKeys for a direct index probe of the PK's unique index.
3448 : *
3449 : * Uses cached compare entries, operator procedures, and strategy numbers
3450 : * from ri_populate_fastpath_metadata() rather than looking them up on
3451 : * each invocation. Casts FK values to the operator's expected input
3452 : * type if needed.
3453 : */
3454 : static void
3455 2398 : build_index_scankeys(const RI_ConstraintInfo *riinfo,
3456 : Relation idx_rel, Datum *pk_vals,
3457 : char *pk_nulls, ScanKey skeys)
3458 : {
3459 2398 : FastPathMeta *fpmeta = riinfo->fpmeta;
3460 :
3461 : Assert(fpmeta);
3462 :
3463 : /*
3464 : * May need to cast each of the individual values of the foreign key to
3465 : * the corresponding PK column's type if the equality operator demands it.
3466 : */
3467 5682 : for (int i = 0; i < riinfo->nkeys; i++)
3468 : {
3469 3284 : if (pk_nulls[i] != 'n' &&
3470 3284 : OidIsValid(fpmeta->cast_func_finfo[i].fn_oid))
3471 276 : pk_vals[i] = FunctionCall3(&fpmeta->cast_func_finfo[i],
3472 : pk_vals[i],
3473 : Int32GetDatum(-1), /* typmod */
3474 : BoolGetDatum(false)); /* implicit coercion */
3475 : }
3476 :
3477 : /*
3478 : * Set up ScanKeys for the index scan. This is essentially how
3479 : * ExecIndexBuildScanKeys() sets them up. Use the cached index_attnos and
3480 : * the corresponding collation since FK columns may be in a different
3481 : * order than PK index columns. Place each scan key at the array position
3482 : * corresponding to its index column, since btree requires keys to be
3483 : * ordered by attribute number.
3484 : */
3485 5682 : for (int i = 0; i < riinfo->nkeys; i++)
3486 : {
3487 3284 : AttrNumber pkattrno = fpmeta->index_attnos[i];
3488 3284 : int skey_pos = pkattrno - 1; /* 0-based array position */
3489 :
3490 3284 : ScanKeyEntryInitialize(&skeys[skey_pos], 0, pkattrno,
3491 3284 : fpmeta->strats[i], fpmeta->subtypes[i],
3492 3284 : idx_rel->rd_indcollation[skey_pos], fpmeta->regops[i],
3493 3284 : pk_vals[i]);
3494 : }
3495 2398 : }
3496 :
3497 : /*
3498 : * ri_populate_fastpath_metadata
3499 : * Cache per-key metadata needed by build_index_scankeys().
3500 : *
3501 : * Looks up the compare hash entry, operator procedure OID, and index
3502 : * strategy/subtype for each key column. Called lazily on first use
3503 : * and persists for the lifetime of the RI_ConstraintInfo entry.
3504 : */
3505 : static void
3506 967 : ri_populate_fastpath_metadata(RI_ConstraintInfo *riinfo,
3507 : Relation fk_rel, Relation idx_rel)
3508 : {
3509 : FastPathMeta *fpmeta;
3510 967 : MemoryContext oldcxt = MemoryContextSwitchTo(TopMemoryContext);
3511 :
3512 : Assert(riinfo != NULL && riinfo->valid);
3513 :
3514 967 : fpmeta = palloc_object(FastPathMeta);
3515 2082 : for (int i = 0; i < riinfo->nkeys; i++)
3516 : {
3517 1115 : Oid eq_opr = riinfo->pf_eq_oprs[i];
3518 1115 : Oid typeid = RIAttType(fk_rel, riinfo->fk_attnums[i]);
3519 : Oid lefttype;
3520 1115 : RI_CompareHashEntry *entry = ri_HashCompareOp(eq_opr, typeid);
3521 : int idx_col;
3522 :
3523 : /*
3524 : * Find the index column position for this constraint key. The FK
3525 : * constraint may reference columns in a different order than they
3526 : * appear in the PK index, so we must map pk_attnums[i] to the
3527 : * corresponding index column position.
3528 : */
3529 1287 : for (idx_col = 0; idx_col < riinfo->nkeys; idx_col++)
3530 : {
3531 1287 : if (idx_rel->rd_index->indkey.values[idx_col] == riinfo->pk_attnums[i])
3532 1115 : break;
3533 : }
3534 : Assert(idx_col < riinfo->nkeys);
3535 :
3536 : /* 1-based attribute number */
3537 1115 : fpmeta->index_attnos[i] = idx_col + 1;
3538 :
3539 1115 : fmgr_info_copy(&fpmeta->cast_func_finfo[i], &entry->cast_func_finfo,
3540 : CurrentMemoryContext);
3541 1115 : fmgr_info_copy(&fpmeta->eq_opr_finfo[i], &entry->eq_opr_finfo,
3542 : CurrentMemoryContext);
3543 1115 : fpmeta->regops[i] = get_opcode(eq_opr);
3544 :
3545 1115 : get_op_opfamily_properties(eq_opr,
3546 1115 : idx_rel->rd_opfamily[idx_col],
3547 : false,
3548 : &fpmeta->strats[i],
3549 : &lefttype,
3550 : &fpmeta->subtypes[i]);
3551 : }
3552 :
3553 967 : riinfo->fpmeta = fpmeta;
3554 967 : MemoryContextSwitchTo(oldcxt);
3555 967 : }
3556 :
3557 : /*
3558 : * Extract fields from a tuple into Datum/nulls arrays
3559 : */
3560 : static void
3561 608010 : ri_ExtractValues(Relation rel, TupleTableSlot *slot,
3562 : const RI_ConstraintInfo *riinfo, bool rel_is_pk,
3563 : Datum *vals, char *nulls)
3564 : {
3565 : const int16 *attnums;
3566 : bool isnull;
3567 :
3568 608010 : if (rel_is_pk)
3569 1829 : attnums = riinfo->pk_attnums;
3570 : else
3571 606181 : attnums = riinfo->fk_attnums;
3572 :
3573 1218039 : for (int i = 0; i < riinfo->nkeys; i++)
3574 : {
3575 610029 : vals[i] = slot_getattr(slot, attnums[i], &isnull);
3576 610029 : nulls[i] = isnull ? 'n' : ' ';
3577 : }
3578 608010 : }
3579 :
3580 : /*
3581 : * Produce an error report
3582 : *
3583 : * If the failed constraint was on insert/update to the FK table,
3584 : * we want the key names and values extracted from there, and the error
3585 : * message to look like 'key blah is not present in PK'.
3586 : * Otherwise, the attr names and values come from the PK table and the
3587 : * message looks like 'key blah is still referenced from FK'.
3588 : */
3589 : static void
3590 833 : ri_ReportViolation(const RI_ConstraintInfo *riinfo,
3591 : Relation pk_rel, Relation fk_rel,
3592 : TupleTableSlot *violatorslot, TupleDesc tupdesc,
3593 : int queryno, bool is_restrict, bool partgone)
3594 : {
3595 : StringInfoData key_names;
3596 : StringInfoData key_values;
3597 : bool onfk;
3598 : const int16 *attnums;
3599 : Oid rel_oid;
3600 : AclResult aclresult;
3601 833 : bool has_perm = true;
3602 :
3603 : /*
3604 : * Determine which relation to complain about. If tupdesc wasn't passed
3605 : * by caller, assume the violator tuple came from there.
3606 : */
3607 833 : onfk = (queryno == RI_PLAN_CHECK_LOOKUPPK);
3608 833 : if (onfk)
3609 : {
3610 481 : attnums = riinfo->fk_attnums;
3611 481 : rel_oid = fk_rel->rd_id;
3612 481 : if (tupdesc == NULL)
3613 430 : tupdesc = fk_rel->rd_att;
3614 : }
3615 : else
3616 : {
3617 352 : attnums = riinfo->pk_attnums;
3618 352 : rel_oid = pk_rel->rd_id;
3619 352 : if (tupdesc == NULL)
3620 330 : tupdesc = pk_rel->rd_att;
3621 : }
3622 :
3623 : /*
3624 : * Check permissions- if the user does not have access to view the data in
3625 : * any of the key columns then we don't include the errdetail() below.
3626 : *
3627 : * Check if RLS is enabled on the relation first. If so, we don't return
3628 : * any specifics to avoid leaking data.
3629 : *
3630 : * Check table-level permissions next and, failing that, column-level
3631 : * privileges.
3632 : *
3633 : * When a partition at the referenced side is being detached/dropped, we
3634 : * needn't check, since the user must be the table owner anyway.
3635 : */
3636 833 : if (partgone)
3637 22 : has_perm = true;
3638 811 : else if (check_enable_rls(rel_oid, InvalidOid, true) != RLS_ENABLED)
3639 : {
3640 807 : aclresult = pg_class_aclcheck(rel_oid, GetUserId(), ACL_SELECT);
3641 807 : if (aclresult != ACLCHECK_OK)
3642 : {
3643 : /* Try for column-level permissions */
3644 0 : for (int idx = 0; idx < riinfo->nkeys; idx++)
3645 : {
3646 0 : aclresult = pg_attribute_aclcheck(rel_oid, attnums[idx],
3647 : GetUserId(),
3648 : ACL_SELECT);
3649 :
3650 : /* No access to the key */
3651 0 : if (aclresult != ACLCHECK_OK)
3652 : {
3653 0 : has_perm = false;
3654 0 : break;
3655 : }
3656 : }
3657 : }
3658 : }
3659 : else
3660 4 : has_perm = false;
3661 :
3662 833 : if (has_perm)
3663 : {
3664 : /* Get printable versions of the keys involved */
3665 829 : initStringInfo(&key_names);
3666 829 : initStringInfo(&key_values);
3667 2045 : for (int idx = 0; idx < riinfo->nkeys; idx++)
3668 : {
3669 1216 : int fnum = attnums[idx];
3670 1216 : Form_pg_attribute att = TupleDescAttr(tupdesc, fnum - 1);
3671 : char *name,
3672 : *val;
3673 : Datum datum;
3674 : bool isnull;
3675 :
3676 1216 : name = NameStr(att->attname);
3677 :
3678 1216 : datum = slot_getattr(violatorslot, fnum, &isnull);
3679 1216 : if (!isnull)
3680 : {
3681 : Oid foutoid;
3682 : bool typisvarlena;
3683 :
3684 1216 : getTypeOutputInfo(att->atttypid, &foutoid, &typisvarlena);
3685 1216 : val = OidOutputFunctionCall(foutoid, datum);
3686 : }
3687 : else
3688 0 : val = "null";
3689 :
3690 1216 : if (idx > 0)
3691 : {
3692 387 : appendStringInfoString(&key_names, ", ");
3693 387 : appendStringInfoString(&key_values, ", ");
3694 : }
3695 1216 : appendStringInfoString(&key_names, name);
3696 1216 : appendStringInfoString(&key_values, val);
3697 : }
3698 : }
3699 :
3700 833 : if (partgone)
3701 22 : ereport(ERROR,
3702 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
3703 : errmsg("removing partition \"%s\" violates foreign key constraint \"%s\"",
3704 : RelationGetRelationName(pk_rel),
3705 : NameStr(riinfo->conname)),
3706 : errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
3707 : key_names.data, key_values.data,
3708 : RelationGetRelationName(fk_rel)),
3709 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
3710 811 : else if (onfk)
3711 481 : ereport(ERROR,
3712 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
3713 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
3714 : RelationGetRelationName(fk_rel),
3715 : NameStr(riinfo->conname)),
3716 : has_perm ?
3717 : errdetail("Key (%s)=(%s) is not present in table \"%s\".",
3718 : key_names.data, key_values.data,
3719 : RelationGetRelationName(pk_rel)) :
3720 : errdetail("Key is not present in table \"%s\".",
3721 : RelationGetRelationName(pk_rel)),
3722 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
3723 330 : else if (is_restrict)
3724 20 : ereport(ERROR,
3725 : (errcode(ERRCODE_RESTRICT_VIOLATION),
3726 : errmsg("update or delete on table \"%s\" violates RESTRICT setting of foreign key constraint \"%s\" on table \"%s\"",
3727 : RelationGetRelationName(pk_rel),
3728 : NameStr(riinfo->conname),
3729 : RelationGetRelationName(fk_rel)),
3730 : has_perm ?
3731 : errdetail("Key (%s)=(%s) is referenced from table \"%s\".",
3732 : key_names.data, key_values.data,
3733 : RelationGetRelationName(fk_rel)) :
3734 : errdetail("Key is referenced from table \"%s\".",
3735 : RelationGetRelationName(fk_rel)),
3736 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
3737 : else
3738 310 : ereport(ERROR,
3739 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
3740 : errmsg("update or delete on table \"%s\" violates foreign key constraint \"%s\" on table \"%s\"",
3741 : RelationGetRelationName(pk_rel),
3742 : NameStr(riinfo->conname),
3743 : RelationGetRelationName(fk_rel)),
3744 : has_perm ?
3745 : errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
3746 : key_names.data, key_values.data,
3747 : RelationGetRelationName(fk_rel)) :
3748 : errdetail("Key is still referenced from table \"%s\".",
3749 : RelationGetRelationName(fk_rel)),
3750 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
3751 : }
3752 :
3753 :
3754 : /*
3755 : * ri_NullCheck -
3756 : *
3757 : * Determine the NULL state of all key values in a tuple
3758 : *
3759 : * Returns one of RI_KEYS_ALL_NULL, RI_KEYS_NONE_NULL or RI_KEYS_SOME_NULL.
3760 : */
3761 : static int
3762 608624 : ri_NullCheck(TupleDesc tupDesc,
3763 : TupleTableSlot *slot,
3764 : const RI_ConstraintInfo *riinfo, bool rel_is_pk)
3765 : {
3766 : const int16 *attnums;
3767 608624 : bool allnull = true;
3768 608624 : bool nonenull = true;
3769 :
3770 608624 : if (rel_is_pk)
3771 1533 : attnums = riinfo->pk_attnums;
3772 : else
3773 607091 : attnums = riinfo->fk_attnums;
3774 :
3775 1219369 : for (int i = 0; i < riinfo->nkeys; i++)
3776 : {
3777 610745 : if (slot_attisnull(slot, attnums[i]))
3778 370 : nonenull = false;
3779 : else
3780 610375 : allnull = false;
3781 : }
3782 :
3783 608624 : if (allnull)
3784 186 : return RI_KEYS_ALL_NULL;
3785 :
3786 608438 : if (nonenull)
3787 608302 : return RI_KEYS_NONE_NULL;
3788 :
3789 136 : return RI_KEYS_SOME_NULL;
3790 : }
3791 :
3792 :
3793 : /*
3794 : * ri_InitHashTables -
3795 : *
3796 : * Initialize our internal hash tables.
3797 : */
3798 : static void
3799 264 : ri_InitHashTables(void)
3800 : {
3801 : HASHCTL ctl;
3802 :
3803 264 : ctl.keysize = sizeof(Oid);
3804 264 : ctl.entrysize = sizeof(RI_ConstraintInfo);
3805 264 : ri_constraint_cache = hash_create("RI constraint cache",
3806 : RI_INIT_CONSTRAINTHASHSIZE,
3807 : &ctl, HASH_ELEM | HASH_BLOBS);
3808 :
3809 : /* Arrange to flush cache on pg_constraint changes */
3810 264 : CacheRegisterSyscacheCallback(CONSTROID,
3811 : InvalidateConstraintCacheCallBack,
3812 : (Datum) 0);
3813 :
3814 264 : ctl.keysize = sizeof(RI_QueryKey);
3815 264 : ctl.entrysize = sizeof(RI_QueryHashEntry);
3816 264 : ri_query_cache = hash_create("RI query cache",
3817 : RI_INIT_QUERYHASHSIZE,
3818 : &ctl, HASH_ELEM | HASH_BLOBS);
3819 :
3820 264 : ctl.keysize = sizeof(RI_CompareKey);
3821 264 : ctl.entrysize = sizeof(RI_CompareHashEntry);
3822 264 : ri_compare_cache = hash_create("RI compare cache",
3823 : RI_INIT_QUERYHASHSIZE,
3824 : &ctl, HASH_ELEM | HASH_BLOBS);
3825 264 : }
3826 :
3827 :
3828 : /*
3829 : * ri_FetchPreparedPlan -
3830 : *
3831 : * Lookup for a query key in our private hash table of prepared
3832 : * and saved SPI execution plans. Return the plan if found or NULL.
3833 : */
3834 : static SPIPlanPtr
3835 2475 : ri_FetchPreparedPlan(RI_QueryKey *key)
3836 : {
3837 : RI_QueryHashEntry *entry;
3838 : SPIPlanPtr plan;
3839 :
3840 : /*
3841 : * On the first call initialize the hashtable
3842 : */
3843 2475 : if (!ri_query_cache)
3844 0 : ri_InitHashTables();
3845 :
3846 : /*
3847 : * Lookup for the key
3848 : */
3849 2475 : entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
3850 : key,
3851 : HASH_FIND, NULL);
3852 2475 : if (entry == NULL)
3853 1020 : return NULL;
3854 :
3855 : /*
3856 : * Check whether the plan is still valid. If it isn't, we don't want to
3857 : * simply rely on plancache.c to regenerate it; rather we should start
3858 : * from scratch and rebuild the query text too. This is to cover cases
3859 : * such as table/column renames. We depend on the plancache machinery to
3860 : * detect possible invalidations, though.
3861 : *
3862 : * CAUTION: this check is only trustworthy if the caller has already
3863 : * locked both FK and PK rels.
3864 : */
3865 1455 : plan = entry->plan;
3866 1455 : if (plan && SPI_plan_is_valid(plan))
3867 1313 : return plan;
3868 :
3869 : /*
3870 : * Otherwise we might as well flush the cached plan now, to free a little
3871 : * memory space before we make a new one.
3872 : */
3873 142 : entry->plan = NULL;
3874 142 : if (plan)
3875 142 : SPI_freeplan(plan);
3876 :
3877 142 : return NULL;
3878 : }
3879 :
3880 :
3881 : /*
3882 : * ri_HashPreparedPlan -
3883 : *
3884 : * Add another plan to our private SPI query plan hashtable.
3885 : */
3886 : static void
3887 1162 : ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan)
3888 : {
3889 : RI_QueryHashEntry *entry;
3890 : bool found;
3891 :
3892 : /*
3893 : * On the first call initialize the hashtable
3894 : */
3895 1162 : if (!ri_query_cache)
3896 0 : ri_InitHashTables();
3897 :
3898 : /*
3899 : * Add the new plan. We might be overwriting an entry previously found
3900 : * invalid by ri_FetchPreparedPlan.
3901 : */
3902 1162 : entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
3903 : key,
3904 : HASH_ENTER, &found);
3905 : Assert(!found || entry->plan == NULL);
3906 1162 : entry->plan = plan;
3907 1162 : }
3908 :
3909 :
3910 : /*
3911 : * ri_KeysEqual -
3912 : *
3913 : * Check if all key values in OLD and NEW are "equivalent":
3914 : * For normal FKs we check for equality.
3915 : * For temporal FKs we check that the PK side is a superset of its old value,
3916 : * or the FK side is a subset of its old value.
3917 : *
3918 : * Note: at some point we might wish to redefine this as checking for
3919 : * "IS NOT DISTINCT" rather than "=", that is, allow two nulls to be
3920 : * considered equal. Currently there is no need since all callers have
3921 : * previously found at least one of the rows to contain no nulls.
3922 : */
3923 : static bool
3924 1423 : ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
3925 : const RI_ConstraintInfo *riinfo, bool rel_is_pk)
3926 : {
3927 : const int16 *attnums;
3928 :
3929 1423 : if (rel_is_pk)
3930 936 : attnums = riinfo->pk_attnums;
3931 : else
3932 487 : attnums = riinfo->fk_attnums;
3933 :
3934 : /* XXX: could be worthwhile to fetch all necessary attrs at once */
3935 2193 : for (int i = 0; i < riinfo->nkeys; i++)
3936 : {
3937 : Datum oldvalue;
3938 : Datum newvalue;
3939 : bool isnull;
3940 :
3941 : /*
3942 : * Get one attribute's oldvalue. If it is NULL - they're not equal.
3943 : */
3944 1643 : oldvalue = slot_getattr(oldslot, attnums[i], &isnull);
3945 1643 : if (isnull)
3946 873 : return false;
3947 :
3948 : /*
3949 : * Get one attribute's newvalue. If it is NULL - they're not equal.
3950 : */
3951 1625 : newvalue = slot_getattr(newslot, attnums[i], &isnull);
3952 1625 : if (isnull)
3953 0 : return false;
3954 :
3955 1625 : if (rel_is_pk)
3956 : {
3957 : /*
3958 : * If we are looking at the PK table, then do a bytewise
3959 : * comparison. We must propagate PK changes if the value is
3960 : * changed to one that "looks" different but would compare as
3961 : * equal using the equality operator. This only makes a
3962 : * difference for ON UPDATE CASCADE, but for consistency we treat
3963 : * all changes to the PK the same.
3964 : */
3965 1100 : CompactAttribute *att = TupleDescCompactAttr(oldslot->tts_tupleDescriptor, attnums[i] - 1);
3966 :
3967 1100 : if (!datum_image_eq(oldvalue, newvalue, att->attbyval, att->attlen))
3968 648 : return false;
3969 : }
3970 : else
3971 : {
3972 : Oid eq_opr;
3973 :
3974 : /*
3975 : * When comparing the PERIOD columns we can skip the check
3976 : * whenever the referencing column stayed equal or shrank, so test
3977 : * with the contained-by operator instead.
3978 : */
3979 525 : if (riinfo->hasperiod && i == riinfo->nkeys - 1)
3980 32 : eq_opr = riinfo->period_contained_by_oper;
3981 : else
3982 493 : eq_opr = riinfo->ff_eq_oprs[i];
3983 :
3984 : /*
3985 : * For the FK table, compare with the appropriate equality
3986 : * operator. Changes that compare equal will still satisfy the
3987 : * constraint after the update.
3988 : */
3989 525 : if (!ri_CompareWithCast(eq_opr, RIAttType(rel, attnums[i]), RIAttCollation(rel, attnums[i]),
3990 : newvalue, oldvalue))
3991 207 : return false;
3992 : }
3993 : }
3994 :
3995 550 : return true;
3996 : }
3997 :
3998 :
3999 : /*
4000 : * ri_CompareWithCast -
4001 : *
4002 : * Call the appropriate comparison operator for two values.
4003 : * Normally this is equality, but for the PERIOD part of foreign keys
4004 : * it is ContainedBy, so the order of lhs vs rhs is significant.
4005 : * See below for how the collation is applied.
4006 : *
4007 : * NB: we have already checked that neither value is null.
4008 : */
4009 : static bool
4010 525 : ri_CompareWithCast(Oid eq_opr, Oid typeid, Oid collid,
4011 : Datum lhs, Datum rhs)
4012 : {
4013 525 : RI_CompareHashEntry *entry = ri_HashCompareOp(eq_opr, typeid);
4014 :
4015 : /* Do we need to cast the values? */
4016 525 : if (OidIsValid(entry->cast_func_finfo.fn_oid))
4017 : {
4018 8 : lhs = FunctionCall3(&entry->cast_func_finfo,
4019 : lhs,
4020 : Int32GetDatum(-1), /* typmod */
4021 : BoolGetDatum(false)); /* implicit coercion */
4022 8 : rhs = FunctionCall3(&entry->cast_func_finfo,
4023 : rhs,
4024 : Int32GetDatum(-1), /* typmod */
4025 : BoolGetDatum(false)); /* implicit coercion */
4026 : }
4027 :
4028 : /*
4029 : * Apply the comparison operator.
4030 : *
4031 : * Note: This function is part of a call stack that determines whether an
4032 : * update to a row is significant enough that it needs checking or action
4033 : * on the other side of a foreign-key constraint. Therefore, the
4034 : * comparison here would need to be done with the collation of the *other*
4035 : * table. For simplicity (e.g., we might not even have the other table
4036 : * open), we'll use our own collation. This is fine because we require
4037 : * that both collations have the same notion of equality (either they are
4038 : * both deterministic or else they are both the same).
4039 : *
4040 : * With range/multirangetypes, the collation of the base type is stored as
4041 : * part of the rangetype (pg_range.rngcollation), and always used, so
4042 : * there is no danger of inconsistency even using a non-equals operator.
4043 : * But if we support arbitrary types with PERIOD, we should perhaps just
4044 : * always force a re-check.
4045 : */
4046 525 : return DatumGetBool(FunctionCall2Coll(&entry->eq_opr_finfo, collid, lhs, rhs));
4047 : }
4048 :
4049 : /*
4050 : * ri_HashCompareOp -
4051 : *
4052 : * Look up or create a cache entry for the given equality operator and
4053 : * the caller's value type (typeid). The entry holds the operator's
4054 : * FmgrInfo and, if typeid doesn't match what the operator expects as
4055 : * its right-hand input, a cast function to coerce the value before
4056 : * comparison.
4057 : */
4058 : static RI_CompareHashEntry *
4059 1640 : ri_HashCompareOp(Oid eq_opr, Oid typeid)
4060 : {
4061 : RI_CompareKey key;
4062 : RI_CompareHashEntry *entry;
4063 : bool found;
4064 :
4065 : /*
4066 : * On the first call initialize the hashtable
4067 : */
4068 1640 : if (!ri_compare_cache)
4069 0 : ri_InitHashTables();
4070 :
4071 : /*
4072 : * Find or create a hash entry. Note we're assuming RI_CompareKey
4073 : * contains no struct padding.
4074 : */
4075 1640 : key.eq_opr = eq_opr;
4076 1640 : key.typeid = typeid;
4077 1640 : entry = (RI_CompareHashEntry *) hash_search(ri_compare_cache,
4078 : &key,
4079 : HASH_ENTER, &found);
4080 1640 : if (!found)
4081 264 : entry->valid = false;
4082 :
4083 : /*
4084 : * If not already initialized, do so. Since we'll keep this hash entry
4085 : * for the life of the backend, put any subsidiary info for the function
4086 : * cache structs into TopMemoryContext.
4087 : */
4088 1640 : if (!entry->valid)
4089 : {
4090 : Oid lefttype,
4091 : righttype,
4092 : castfunc;
4093 : CoercionPathType pathtype;
4094 :
4095 : /* We always need to know how to call the equality operator */
4096 264 : fmgr_info_cxt(get_opcode(eq_opr), &entry->eq_opr_finfo,
4097 : TopMemoryContext);
4098 :
4099 : /*
4100 : * If we chose to use a cast from FK to PK type, we may have to apply
4101 : * the cast function to get to the operator's input type.
4102 : *
4103 : * XXX eventually it would be good to support array-coercion cases
4104 : * here and in ri_CompareWithCast(). At the moment there is no point
4105 : * because cases involving nonidentical array types will be rejected
4106 : * at constraint creation time.
4107 : *
4108 : * XXX perhaps also consider supporting CoerceViaIO? No need at the
4109 : * moment since that will never be generated for implicit coercions.
4110 : */
4111 264 : op_input_types(eq_opr, &lefttype, &righttype);
4112 :
4113 : /*
4114 : * pf_eq_oprs (used by the fast path) can be cross-type when the FK
4115 : * and PK columns differ in type, e.g. int48eq for int4 PK / int8 FK.
4116 : * If the FK column's type, or the base type of a domain over it,
4117 : * already matches what the operator expects as its right-hand input,
4118 : * no cast is needed.
4119 : */
4120 264 : if (getBaseType(typeid) == righttype)
4121 236 : castfunc = InvalidOid; /* simplest case */
4122 : else
4123 : {
4124 28 : pathtype = find_coercion_pathway(lefttype, typeid,
4125 : COERCION_IMPLICIT,
4126 : &castfunc);
4127 28 : if (pathtype != COERCION_PATH_FUNC &&
4128 : pathtype != COERCION_PATH_RELABELTYPE)
4129 : {
4130 : /*
4131 : * The declared input type of the eq_opr might be a
4132 : * polymorphic type such as ANYARRAY or ANYENUM, or other
4133 : * special cases such as RECORD; find_coercion_pathway
4134 : * currently doesn't subsume these special cases.
4135 : */
4136 16 : if (!IsBinaryCoercible(typeid, lefttype))
4137 0 : elog(ERROR, "no conversion function from %s to %s",
4138 : format_type_be(typeid),
4139 : format_type_be(lefttype));
4140 : }
4141 : }
4142 264 : if (OidIsValid(castfunc))
4143 12 : fmgr_info_cxt(castfunc, &entry->cast_func_finfo,
4144 : TopMemoryContext);
4145 : else
4146 252 : entry->cast_func_finfo.fn_oid = InvalidOid;
4147 264 : entry->valid = true;
4148 : }
4149 :
4150 1640 : return entry;
4151 : }
4152 :
4153 :
4154 : /*
4155 : * Given a trigger function OID, determine whether it is an RI trigger,
4156 : * and if so whether it is attached to PK or FK relation.
4157 : */
4158 : int
4159 5788 : RI_FKey_trigger_type(Oid tgfoid)
4160 : {
4161 5788 : switch (tgfoid)
4162 : {
4163 2033 : case F_RI_FKEY_CASCADE_DEL:
4164 : case F_RI_FKEY_CASCADE_UPD:
4165 : case F_RI_FKEY_RESTRICT_DEL:
4166 : case F_RI_FKEY_RESTRICT_UPD:
4167 : case F_RI_FKEY_SETNULL_DEL:
4168 : case F_RI_FKEY_SETNULL_UPD:
4169 : case F_RI_FKEY_SETDEFAULT_DEL:
4170 : case F_RI_FKEY_SETDEFAULT_UPD:
4171 : case F_RI_FKEY_NOACTION_DEL:
4172 : case F_RI_FKEY_NOACTION_UPD:
4173 2033 : return RI_TRIGGER_PK;
4174 :
4175 1850 : case F_RI_FKEY_CHECK_INS:
4176 : case F_RI_FKEY_CHECK_UPD:
4177 1850 : return RI_TRIGGER_FK;
4178 : }
4179 :
4180 1905 : return RI_TRIGGER_NONE;
4181 : }
4182 :
4183 : /*
4184 : * ri_FastPathEndBatch
4185 : * Flush remaining rows and tear down cached state.
4186 : *
4187 : * Registered as an AfterTriggerBatchCallback. Note: the flush can
4188 : * do real work (CCI, security context switch, index probes) and can
4189 : * throw ERROR on a constraint violation. If that happens,
4190 : * ri_FastPathTeardown never runs; ResourceOwner + XactCallback
4191 : * handle resource cleanup on the abort path.
4192 : */
4193 : static void
4194 1505 : ri_FastPathEndBatch(void *arg)
4195 : {
4196 : HASH_SEQ_STATUS status;
4197 : RI_FastPathEntry *entry;
4198 :
4199 1505 : if (ri_fastpath_cache == NULL)
4200 0 : return;
4201 :
4202 : /*
4203 : * Set a flag for the duration of the scan so that any FK check triggered
4204 : * by user cast or operator code during a flush takes the per-row path
4205 : * instead of adding a new entry to the cache we are iterating. A new
4206 : * entry could land in an already-scanned bucket and then be torn down
4207 : * unflushed below.
4208 : *
4209 : * The flush can throw ERROR (a reported constraint violation, or an error
4210 : * from the user code it runs). In that case ri_FastPathTeardown below is
4211 : * skipped; the ResourceOwner and the transaction-end callback handle
4212 : * resource cleanup on the abort path. The PG_FINALLY only resets the
4213 : * flag and deliberately does not attempt teardown.
4214 : */
4215 : Assert(!ri_fastpath_flushing);
4216 1505 : ri_fastpath_flushing = true;
4217 1505 : PG_TRY();
4218 : {
4219 1505 : hash_seq_init(&status, ri_fastpath_cache);
4220 4439 : while ((entry = hash_seq_search(&status)) != NULL)
4221 : {
4222 1727 : if (entry->batch_count > 0)
4223 : {
4224 1719 : Relation fk_rel = table_open(entry->fk_relid, AccessShareLock);
4225 1719 : RI_ConstraintInfo *riinfo = ri_LoadConstraintInfo(entry->conoid);
4226 :
4227 1719 : ri_FastPathBatchFlush(entry, fk_rel, riinfo);
4228 1421 : table_close(fk_rel, NoLock);
4229 : }
4230 : }
4231 : }
4232 298 : PG_FINALLY();
4233 : {
4234 1505 : ri_fastpath_flushing = false;
4235 : }
4236 1505 : PG_END_TRY();
4237 :
4238 1207 : ri_FastPathTeardown();
4239 : }
4240 :
4241 : /*
4242 : * ri_FastPathTeardown
4243 : * Tear down all cached fast-path state.
4244 : *
4245 : * Called from ri_FastPathEndBatch() after flushing any remaining rows.
4246 : */
4247 : static void
4248 1207 : ri_FastPathTeardown(void)
4249 : {
4250 : HASH_SEQ_STATUS status;
4251 : RI_FastPathEntry *entry;
4252 :
4253 1207 : if (ri_fastpath_cache == NULL)
4254 0 : return;
4255 :
4256 1207 : hash_seq_init(&status, ri_fastpath_cache);
4257 3827 : while ((entry = hash_seq_search(&status)) != NULL)
4258 : {
4259 1413 : if (entry->idx_rel)
4260 1413 : index_close(entry->idx_rel, NoLock);
4261 1413 : if (entry->pk_rel)
4262 1413 : table_close(entry->pk_rel, NoLock);
4263 1413 : if (entry->pk_slot)
4264 1413 : ExecDropSingleTupleTableSlot(entry->pk_slot);
4265 1413 : if (entry->fk_slot)
4266 1413 : ExecDropSingleTupleTableSlot(entry->fk_slot);
4267 1413 : if (entry->flush_cxt)
4268 1413 : MemoryContextDelete(entry->flush_cxt);
4269 : }
4270 :
4271 1207 : hash_destroy(ri_fastpath_cache);
4272 1207 : ri_fastpath_cache = NULL;
4273 1207 : ri_fastpath_callback_registered = false;
4274 : }
4275 :
4276 : static bool ri_fastpath_xact_callback_registered = false;
4277 :
4278 : static void
4279 74261 : ri_FastPathXactCallback(XactEvent event, void *arg)
4280 : {
4281 : /*
4282 : * On abort, ResourceOwner already released relations; on commit,
4283 : * ri_FastPathTeardown already ran. Either way, just NULL the static
4284 : * pointers so they don't dangle into the next transaction.
4285 : */
4286 74261 : ri_fastpath_cache = NULL;
4287 74261 : ri_fastpath_callback_registered = false;
4288 :
4289 : /*
4290 : * Also clear the in-flush flag. ri_FastPathEndBatch() already clears it
4291 : * via PG_FINALLY, so this is just defensive: it keeps a stale flag from
4292 : * surviving into the next transaction should any future path leave it
4293 : * set.
4294 : */
4295 74261 : ri_fastpath_flushing = false;
4296 74261 : }
4297 :
4298 : /*
4299 : * ri_FastPathGetEntry
4300 : * Look up or create a per-batch cache entry for the given constraint.
4301 : *
4302 : * On first call for a constraint within a batch: opens pk_rel and the index,
4303 : * allocates slots for both FK row and the looked up PK row, and registers the
4304 : * cleanup callback.
4305 : *
4306 : * On subsequent calls: returns the existing entry.
4307 : */
4308 : static RI_FastPathEntry *
4309 605223 : ri_FastPathGetEntry(const RI_ConstraintInfo *riinfo, Relation fk_rel)
4310 : {
4311 : RI_FastPathEntry *entry;
4312 : bool found;
4313 :
4314 : /* Create hash table on first use in this batch */
4315 605223 : if (ri_fastpath_cache == NULL)
4316 : {
4317 : HASHCTL ctl;
4318 :
4319 1505 : if (!ri_fastpath_xact_callback_registered)
4320 : {
4321 213 : RegisterXactCallback(ri_FastPathXactCallback, NULL);
4322 213 : ri_fastpath_xact_callback_registered = true;
4323 : }
4324 :
4325 1505 : ctl.keysize = sizeof(Oid);
4326 1505 : ctl.entrysize = sizeof(RI_FastPathEntry);
4327 1505 : ctl.hcxt = TopTransactionContext;
4328 1505 : ri_fastpath_cache = hash_create("RI fast-path cache",
4329 : 16,
4330 : &ctl,
4331 : HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
4332 : }
4333 :
4334 605223 : entry = hash_search(ri_fastpath_cache, &riinfo->constraint_id,
4335 : HASH_ENTER, &found);
4336 :
4337 605223 : if (!found)
4338 : {
4339 : MemoryContext oldcxt;
4340 :
4341 : /*
4342 : * Zero out non-key fields so ri_FastPathTeardown is safe if we error
4343 : * out during partial initialization below.
4344 : */
4345 1739 : memset(((char *) entry) + offsetof(RI_FastPathEntry, pk_rel), 0,
4346 : sizeof(RI_FastPathEntry) - offsetof(RI_FastPathEntry, pk_rel));
4347 :
4348 1739 : oldcxt = MemoryContextSwitchTo(TopTransactionContext);
4349 :
4350 1739 : entry->fk_relid = RelationGetRelid(fk_rel);
4351 :
4352 : /*
4353 : * Open PK table and its unique index.
4354 : *
4355 : * RowShareLock on pk_rel matches what the SPI path's SELECT ... FOR
4356 : * KEY SHARE would acquire as a relation-level lock. AccessShareLock
4357 : * on the index is standard for index scans.
4358 : *
4359 : * We don't release these locks until end of transaction, matching SPI
4360 : * behavior.
4361 : */
4362 1739 : entry->pk_rel = table_open(riinfo->pk_relid, RowShareLock);
4363 1739 : entry->idx_rel = index_open(riinfo->conindid, AccessShareLock);
4364 1739 : entry->pk_slot = table_slot_create(entry->pk_rel, NULL);
4365 :
4366 : /*
4367 : * Must be TTSOpsHeapTuple because ExecStoreHeapTuple() is used to
4368 : * load entries from batch[] into this slot for value extraction.
4369 : */
4370 1739 : entry->fk_slot = MakeSingleTupleTableSlot(RelationGetDescr(fk_rel),
4371 : &TTSOpsHeapTuple);
4372 :
4373 1739 : entry->flush_cxt = AllocSetContextCreate(TopTransactionContext,
4374 : "RI fast path flush temporary context",
4375 : ALLOCSET_SMALL_SIZES);
4376 1739 : MemoryContextSwitchTo(oldcxt);
4377 :
4378 : /* Ensure cleanup at end of this trigger-firing batch */
4379 1739 : if (!ri_fastpath_callback_registered)
4380 : {
4381 1505 : RegisterAfterTriggerBatchCallback(ri_FastPathEndBatch, NULL);
4382 1505 : ri_fastpath_callback_registered = true;
4383 : }
4384 :
4385 1739 : entry->flushing = false;
4386 1739 : entry->batch_count = 0;
4387 : }
4388 :
4389 605223 : return entry;
4390 : }
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