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) 1996-2019, 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/htup_details.h"
27 : #include "access/sysattr.h"
28 : #include "access/table.h"
29 : #include "access/tableam.h"
30 : #include "access/xact.h"
31 : #include "catalog/pg_collation.h"
32 : #include "catalog/pg_constraint.h"
33 : #include "catalog/pg_operator.h"
34 : #include "catalog/pg_type.h"
35 : #include "commands/trigger.h"
36 : #include "executor/executor.h"
37 : #include "executor/spi.h"
38 : #include "lib/ilist.h"
39 : #include "parser/parse_coerce.h"
40 : #include "parser/parse_relation.h"
41 : #include "miscadmin.h"
42 : #include "storage/bufmgr.h"
43 : #include "utils/acl.h"
44 : #include "utils/builtins.h"
45 : #include "utils/datum.h"
46 : #include "utils/fmgroids.h"
47 : #include "utils/guc.h"
48 : #include "utils/inval.h"
49 : #include "utils/lsyscache.h"
50 : #include "utils/memutils.h"
51 : #include "utils/rel.h"
52 : #include "utils/rls.h"
53 : #include "utils/ruleutils.h"
54 : #include "utils/snapmgr.h"
55 : #include "utils/syscache.h"
56 :
57 :
58 : /*
59 : * Local definitions
60 : */
61 :
62 : #define RI_MAX_NUMKEYS INDEX_MAX_KEYS
63 :
64 : #define RI_INIT_CONSTRAINTHASHSIZE 64
65 : #define RI_INIT_QUERYHASHSIZE (RI_INIT_CONSTRAINTHASHSIZE * 4)
66 :
67 : #define RI_KEYS_ALL_NULL 0
68 : #define RI_KEYS_SOME_NULL 1
69 : #define RI_KEYS_NONE_NULL 2
70 :
71 : /* RI query type codes */
72 : /* these queries are executed against the PK (referenced) table: */
73 : #define RI_PLAN_CHECK_LOOKUPPK 1
74 : #define RI_PLAN_CHECK_LOOKUPPK_FROM_PK 2
75 : #define RI_PLAN_LAST_ON_PK RI_PLAN_CHECK_LOOKUPPK_FROM_PK
76 : /* these queries are executed against the FK (referencing) table: */
77 : #define RI_PLAN_CASCADE_DEL_DODELETE 3
78 : #define RI_PLAN_CASCADE_UPD_DOUPDATE 4
79 : #define RI_PLAN_RESTRICT_CHECKREF 5
80 : #define RI_PLAN_SETNULL_DOUPDATE 6
81 : #define RI_PLAN_SETDEFAULT_DOUPDATE 7
82 :
83 : #define MAX_QUOTED_NAME_LEN (NAMEDATALEN*2+3)
84 : #define MAX_QUOTED_REL_NAME_LEN (MAX_QUOTED_NAME_LEN*2)
85 :
86 : #define RIAttName(rel, attnum) NameStr(*attnumAttName(rel, attnum))
87 : #define RIAttType(rel, attnum) attnumTypeId(rel, attnum)
88 : #define RIAttCollation(rel, attnum) attnumCollationId(rel, attnum)
89 :
90 : #define RI_TRIGTYPE_INSERT 1
91 : #define RI_TRIGTYPE_UPDATE 2
92 : #define RI_TRIGTYPE_DELETE 3
93 :
94 :
95 : /*
96 : * RI_ConstraintInfo
97 : *
98 : * Information extracted from an FK pg_constraint entry. This is cached in
99 : * ri_constraint_cache.
100 : */
101 : typedef struct RI_ConstraintInfo
102 : {
103 : Oid constraint_id; /* OID of pg_constraint entry (hash key) */
104 : bool valid; /* successfully initialized? */
105 : uint32 oidHashValue; /* hash value of pg_constraint OID */
106 : NameData conname; /* name of the FK constraint */
107 : Oid pk_relid; /* referenced relation */
108 : Oid fk_relid; /* referencing relation */
109 : char confupdtype; /* foreign key's ON UPDATE action */
110 : char confdeltype; /* foreign key's ON DELETE action */
111 : char confmatchtype; /* foreign key's match type */
112 : int nkeys; /* number of key columns */
113 : int16 pk_attnums[RI_MAX_NUMKEYS]; /* attnums of referenced cols */
114 : int16 fk_attnums[RI_MAX_NUMKEYS]; /* attnums of referencing cols */
115 : Oid pf_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = FK) */
116 : Oid pp_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK = PK) */
117 : Oid ff_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (FK = FK) */
118 : dlist_node valid_link; /* Link in list of valid entries */
119 : } RI_ConstraintInfo;
120 :
121 : /*
122 : * RI_QueryKey
123 : *
124 : * The key identifying a prepared SPI plan in our query hashtable
125 : */
126 : typedef struct RI_QueryKey
127 : {
128 : Oid constr_id; /* OID of pg_constraint entry */
129 : int32 constr_queryno; /* query type ID, see RI_PLAN_XXX above */
130 : } RI_QueryKey;
131 :
132 : /*
133 : * RI_QueryHashEntry
134 : */
135 : typedef struct RI_QueryHashEntry
136 : {
137 : RI_QueryKey key;
138 : SPIPlanPtr plan;
139 : } RI_QueryHashEntry;
140 :
141 : /*
142 : * RI_CompareKey
143 : *
144 : * The key identifying an entry showing how to compare two values
145 : */
146 : typedef struct RI_CompareKey
147 : {
148 : Oid eq_opr; /* the equality operator to apply */
149 : Oid typeid; /* the data type to apply it to */
150 : } RI_CompareKey;
151 :
152 : /*
153 : * RI_CompareHashEntry
154 : */
155 : typedef struct RI_CompareHashEntry
156 : {
157 : RI_CompareKey key;
158 : bool valid; /* successfully initialized? */
159 : FmgrInfo eq_opr_finfo; /* call info for equality fn */
160 : FmgrInfo cast_func_finfo; /* in case we must coerce input */
161 : } RI_CompareHashEntry;
162 :
163 :
164 : /*
165 : * Local data
166 : */
167 : static HTAB *ri_constraint_cache = NULL;
168 : static HTAB *ri_query_cache = NULL;
169 : static HTAB *ri_compare_cache = NULL;
170 : static dlist_head ri_constraint_cache_valid_list;
171 : static int ri_constraint_cache_valid_count = 0;
172 :
173 :
174 : /*
175 : * Local function prototypes
176 : */
177 : static bool ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
178 : TupleTableSlot *oldslot,
179 : const RI_ConstraintInfo *riinfo);
180 : static Datum ri_restrict(TriggerData *trigdata, bool is_no_action);
181 : static Datum ri_set(TriggerData *trigdata, bool is_set_null);
182 : static void quoteOneName(char *buffer, const char *name);
183 : static void quoteRelationName(char *buffer, Relation rel);
184 : static void ri_GenerateQual(StringInfo buf,
185 : const char *sep,
186 : const char *leftop, Oid leftoptype,
187 : Oid opoid,
188 : const char *rightop, Oid rightoptype);
189 : static void ri_GenerateQualCollation(StringInfo buf, Oid collation);
190 : static int ri_NullCheck(TupleDesc tupdesc, TupleTableSlot *slot,
191 : const RI_ConstraintInfo *riinfo, bool rel_is_pk);
192 : static void ri_BuildQueryKey(RI_QueryKey *key,
193 : const RI_ConstraintInfo *riinfo,
194 : int32 constr_queryno);
195 : static bool ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
196 : const RI_ConstraintInfo *riinfo, bool rel_is_pk);
197 : static bool ri_AttributesEqual(Oid eq_opr, Oid typeid,
198 : Datum oldvalue, Datum newvalue);
199 :
200 : static void ri_InitHashTables(void);
201 : static void InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue);
202 : static SPIPlanPtr ri_FetchPreparedPlan(RI_QueryKey *key);
203 : static void ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan);
204 : static RI_CompareHashEntry *ri_HashCompareOp(Oid eq_opr, Oid typeid);
205 :
206 : static void ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname,
207 : int tgkind);
208 : static const RI_ConstraintInfo *ri_FetchConstraintInfo(Trigger *trigger,
209 : Relation trig_rel, bool rel_is_pk);
210 : static const RI_ConstraintInfo *ri_LoadConstraintInfo(Oid constraintOid);
211 : static SPIPlanPtr ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
212 : RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel,
213 : bool cache_plan);
214 : static bool ri_PerformCheck(const RI_ConstraintInfo *riinfo,
215 : RI_QueryKey *qkey, SPIPlanPtr qplan,
216 : Relation fk_rel, Relation pk_rel,
217 : TupleTableSlot *oldslot, TupleTableSlot *newslot,
218 : bool detectNewRows, int expect_OK);
219 : static void ri_ExtractValues(Relation rel, TupleTableSlot *slot,
220 : const RI_ConstraintInfo *riinfo, bool rel_is_pk,
221 : Datum *vals, char *nulls);
222 : static void ri_ReportViolation(const RI_ConstraintInfo *riinfo,
223 : Relation pk_rel, Relation fk_rel,
224 : TupleTableSlot *violatorslot, TupleDesc tupdesc,
225 : int queryno, bool partgone) pg_attribute_noreturn();
226 :
227 :
228 : /*
229 : * RI_FKey_check -
230 : *
231 : * Check foreign key existence (combined for INSERT and UPDATE).
232 : */
233 : static Datum
234 2738 : RI_FKey_check(TriggerData *trigdata)
235 : {
236 : const RI_ConstraintInfo *riinfo;
237 : Relation fk_rel;
238 : Relation pk_rel;
239 : TupleTableSlot *newslot;
240 : RI_QueryKey qkey;
241 : SPIPlanPtr qplan;
242 :
243 2738 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
244 : trigdata->tg_relation, false);
245 :
246 2738 : if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
247 214 : newslot = trigdata->tg_newslot;
248 : else
249 2524 : newslot = trigdata->tg_trigslot;
250 :
251 : /*
252 : * We should not even consider checking the row if it is no longer valid,
253 : * since it was either deleted (so the deferred check should be skipped)
254 : * or updated (in which case only the latest version of the row should be
255 : * checked). Test its liveness according to SnapshotSelf. We need pin
256 : * and lock on the buffer to call HeapTupleSatisfiesVisibility. Caller
257 : * should be holding pin, but not lock.
258 : */
259 2738 : if (!table_tuple_satisfies_snapshot(trigdata->tg_relation, newslot, SnapshotSelf))
260 40 : return PointerGetDatum(NULL);
261 :
262 : /*
263 : * Get the relation descriptors of the FK and PK tables.
264 : *
265 : * pk_rel is opened in RowShareLock mode since that's what our eventual
266 : * SELECT FOR KEY SHARE will get on it.
267 : */
268 2698 : fk_rel = trigdata->tg_relation;
269 2698 : pk_rel = table_open(riinfo->pk_relid, RowShareLock);
270 :
271 2698 : switch (ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false))
272 : {
273 : case RI_KEYS_ALL_NULL:
274 :
275 : /*
276 : * No further check needed - an all-NULL key passes every type of
277 : * foreign key constraint.
278 : */
279 92 : table_close(pk_rel, RowShareLock);
280 92 : return PointerGetDatum(NULL);
281 :
282 : case RI_KEYS_SOME_NULL:
283 :
284 : /*
285 : * This is the only case that differs between the three kinds of
286 : * MATCH.
287 : */
288 92 : switch (riinfo->confmatchtype)
289 : {
290 : case FKCONSTR_MATCH_FULL:
291 :
292 : /*
293 : * Not allowed - MATCH FULL says either all or none of the
294 : * attributes can be NULLs
295 : */
296 24 : ereport(ERROR,
297 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
298 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
299 : RelationGetRelationName(fk_rel),
300 : NameStr(riinfo->conname)),
301 : errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
302 : errtableconstraint(fk_rel,
303 : NameStr(riinfo->conname))));
304 : table_close(pk_rel, RowShareLock);
305 : return PointerGetDatum(NULL);
306 :
307 : case FKCONSTR_MATCH_SIMPLE:
308 :
309 : /*
310 : * MATCH SIMPLE - if ANY column is null, the key passes
311 : * the constraint.
312 : */
313 68 : table_close(pk_rel, RowShareLock);
314 68 : return PointerGetDatum(NULL);
315 :
316 : #ifdef NOT_USED
317 : case FKCONSTR_MATCH_PARTIAL:
318 :
319 : /*
320 : * MATCH PARTIAL - all non-null columns must match. (not
321 : * implemented, can be done by modifying the query below
322 : * to only include non-null columns, or by writing a
323 : * special version here)
324 : */
325 : break;
326 : #endif
327 : }
328 :
329 : case RI_KEYS_NONE_NULL:
330 :
331 : /*
332 : * Have a full qualified key - continue below for all three kinds
333 : * of MATCH.
334 : */
335 2514 : break;
336 : }
337 :
338 2514 : if (SPI_connect() != SPI_OK_CONNECT)
339 0 : elog(ERROR, "SPI_connect failed");
340 :
341 : /* Fetch or prepare a saved plan for the real check */
342 2514 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK);
343 :
344 2514 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
345 : {
346 : StringInfoData querybuf;
347 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
348 : char attname[MAX_QUOTED_NAME_LEN];
349 : char paramname[16];
350 : const char *querysep;
351 : Oid queryoids[RI_MAX_NUMKEYS];
352 : const char *pk_only;
353 :
354 : /* ----------
355 : * The query string built is
356 : * SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
357 : * FOR KEY SHARE OF x
358 : * The type id's for the $ parameters are those of the
359 : * corresponding FK attributes.
360 : * ----------
361 : */
362 1590 : initStringInfo(&querybuf);
363 3180 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
364 1590 : "" : "ONLY ";
365 1590 : quoteRelationName(pkrelname, pk_rel);
366 1590 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
367 : pk_only, pkrelname);
368 1590 : querysep = "WHERE";
369 3308 : for (int i = 0; i < riinfo->nkeys; i++)
370 : {
371 1718 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
372 1718 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
373 :
374 1718 : quoteOneName(attname,
375 1718 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
376 1718 : sprintf(paramname, "$%d", i + 1);
377 1718 : ri_GenerateQual(&querybuf, querysep,
378 : attname, pk_type,
379 : riinfo->pf_eq_oprs[i],
380 : paramname, fk_type);
381 1718 : querysep = "AND";
382 1718 : queryoids[i] = fk_type;
383 : }
384 1590 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
385 :
386 : /* Prepare and save the plan */
387 1590 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
388 : &qkey, fk_rel, pk_rel, true);
389 : }
390 :
391 : /*
392 : * Now check that foreign key exists in PK table
393 : */
394 2514 : ri_PerformCheck(riinfo, &qkey, qplan,
395 : fk_rel, pk_rel,
396 : NULL, newslot,
397 : false,
398 : SPI_OK_SELECT);
399 :
400 2242 : if (SPI_finish() != SPI_OK_FINISH)
401 0 : elog(ERROR, "SPI_finish failed");
402 :
403 2242 : table_close(pk_rel, RowShareLock);
404 :
405 2242 : return PointerGetDatum(NULL);
406 : }
407 :
408 :
409 : /*
410 : * RI_FKey_check_ins -
411 : *
412 : * Check foreign key existence at insert event on FK table.
413 : */
414 : Datum
415 2524 : RI_FKey_check_ins(PG_FUNCTION_ARGS)
416 : {
417 : /* Check that this is a valid trigger call on the right time and event. */
418 2524 : ri_CheckTrigger(fcinfo, "RI_FKey_check_ins", RI_TRIGTYPE_INSERT);
419 :
420 : /* Share code with UPDATE case. */
421 2524 : return RI_FKey_check((TriggerData *) fcinfo->context);
422 : }
423 :
424 :
425 : /*
426 : * RI_FKey_check_upd -
427 : *
428 : * Check foreign key existence at update event on FK table.
429 : */
430 : Datum
431 214 : RI_FKey_check_upd(PG_FUNCTION_ARGS)
432 : {
433 : /* Check that this is a valid trigger call on the right time and event. */
434 214 : ri_CheckTrigger(fcinfo, "RI_FKey_check_upd", RI_TRIGTYPE_UPDATE);
435 :
436 : /* Share code with INSERT case. */
437 214 : return RI_FKey_check((TriggerData *) fcinfo->context);
438 : }
439 :
440 :
441 : /*
442 : * ri_Check_Pk_Match
443 : *
444 : * Check to see if another PK row has been created that provides the same
445 : * key values as the "oldslot" that's been modified or deleted in our trigger
446 : * event. Returns true if a match is found in the PK table.
447 : *
448 : * We assume the caller checked that the oldslot contains no NULL key values,
449 : * since otherwise a match is impossible.
450 : */
451 : static bool
452 432 : ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
453 : TupleTableSlot *oldslot,
454 : const RI_ConstraintInfo *riinfo)
455 : {
456 : SPIPlanPtr qplan;
457 : RI_QueryKey qkey;
458 : bool result;
459 :
460 : /* Only called for non-null rows */
461 : Assert(ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) == RI_KEYS_NONE_NULL);
462 :
463 432 : if (SPI_connect() != SPI_OK_CONNECT)
464 0 : elog(ERROR, "SPI_connect failed");
465 :
466 : /*
467 : * Fetch or prepare a saved plan for checking PK table with values coming
468 : * from a PK row
469 : */
470 432 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK_FROM_PK);
471 :
472 432 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
473 : {
474 : StringInfoData querybuf;
475 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
476 : char attname[MAX_QUOTED_NAME_LEN];
477 : char paramname[16];
478 : const char *querysep;
479 : const char *pk_only;
480 : Oid queryoids[RI_MAX_NUMKEYS];
481 :
482 : /* ----------
483 : * The query string built is
484 : * SELECT 1 FROM [ONLY] <pktable> x WHERE pkatt1 = $1 [AND ...]
485 : * FOR KEY SHARE OF x
486 : * The type id's for the $ parameters are those of the
487 : * PK attributes themselves.
488 : * ----------
489 : */
490 200 : initStringInfo(&querybuf);
491 400 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
492 200 : "" : "ONLY ";
493 200 : quoteRelationName(pkrelname, pk_rel);
494 200 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
495 : pk_only, pkrelname);
496 200 : querysep = "WHERE";
497 466 : for (int i = 0; i < riinfo->nkeys; i++)
498 : {
499 266 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
500 :
501 266 : quoteOneName(attname,
502 266 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
503 266 : sprintf(paramname, "$%d", i + 1);
504 266 : ri_GenerateQual(&querybuf, querysep,
505 : attname, pk_type,
506 : riinfo->pp_eq_oprs[i],
507 : paramname, pk_type);
508 266 : querysep = "AND";
509 266 : queryoids[i] = pk_type;
510 : }
511 200 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
512 :
513 : /* Prepare and save the plan */
514 200 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
515 : &qkey, fk_rel, pk_rel, true);
516 : }
517 :
518 : /*
519 : * We have a plan now. Run it.
520 : */
521 432 : result = ri_PerformCheck(riinfo, &qkey, qplan,
522 : fk_rel, pk_rel,
523 : oldslot, NULL,
524 : true, /* treat like update */
525 : SPI_OK_SELECT);
526 :
527 432 : if (SPI_finish() != SPI_OK_FINISH)
528 0 : elog(ERROR, "SPI_finish failed");
529 :
530 432 : return result;
531 : }
532 :
533 :
534 : /*
535 : * RI_FKey_noaction_del -
536 : *
537 : * Give an error and roll back the current transaction if the
538 : * delete has resulted in a violation of the given referential
539 : * integrity constraint.
540 : */
541 : Datum
542 212 : RI_FKey_noaction_del(PG_FUNCTION_ARGS)
543 : {
544 : /* Check that this is a valid trigger call on the right time and event. */
545 212 : ri_CheckTrigger(fcinfo, "RI_FKey_noaction_del", RI_TRIGTYPE_DELETE);
546 :
547 : /* Share code with RESTRICT/UPDATE cases. */
548 212 : return ri_restrict((TriggerData *) fcinfo->context, true);
549 : }
550 :
551 : /*
552 : * RI_FKey_restrict_del -
553 : *
554 : * Restrict delete from PK table to rows unreferenced by foreign key.
555 : *
556 : * The SQL standard intends that this referential action occur exactly when
557 : * the delete is performed, rather than after. This appears to be
558 : * the only difference between "NO ACTION" and "RESTRICT". In Postgres
559 : * we still implement this as an AFTER trigger, but it's non-deferrable.
560 : */
561 : Datum
562 12 : RI_FKey_restrict_del(PG_FUNCTION_ARGS)
563 : {
564 : /* Check that this is a valid trigger call on the right time and event. */
565 12 : ri_CheckTrigger(fcinfo, "RI_FKey_restrict_del", RI_TRIGTYPE_DELETE);
566 :
567 : /* Share code with NO ACTION/UPDATE cases. */
568 12 : return ri_restrict((TriggerData *) fcinfo->context, false);
569 : }
570 :
571 : /*
572 : * RI_FKey_noaction_upd -
573 : *
574 : * Give an error and roll back the current transaction if the
575 : * update has resulted in a violation of the given referential
576 : * integrity constraint.
577 : */
578 : Datum
579 152 : RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
580 : {
581 : /* Check that this is a valid trigger call on the right time and event. */
582 152 : ri_CheckTrigger(fcinfo, "RI_FKey_noaction_upd", RI_TRIGTYPE_UPDATE);
583 :
584 : /* Share code with RESTRICT/DELETE cases. */
585 152 : return ri_restrict((TriggerData *) fcinfo->context, true);
586 : }
587 :
588 : /*
589 : * RI_FKey_restrict_upd -
590 : *
591 : * Restrict update of PK to rows unreferenced by foreign key.
592 : *
593 : * The SQL standard intends that this referential action occur exactly when
594 : * the update is performed, rather than after. This appears to be
595 : * the only difference between "NO ACTION" and "RESTRICT". In Postgres
596 : * we still implement this as an AFTER trigger, but it's non-deferrable.
597 : */
598 : Datum
599 12 : RI_FKey_restrict_upd(PG_FUNCTION_ARGS)
600 : {
601 : /* Check that this is a valid trigger call on the right time and event. */
602 12 : ri_CheckTrigger(fcinfo, "RI_FKey_restrict_upd", RI_TRIGTYPE_UPDATE);
603 :
604 : /* Share code with NO ACTION/DELETE cases. */
605 12 : return ri_restrict((TriggerData *) fcinfo->context, false);
606 : }
607 :
608 : /*
609 : * ri_restrict -
610 : *
611 : * Common code for ON DELETE RESTRICT, ON DELETE NO ACTION,
612 : * ON UPDATE RESTRICT, and ON UPDATE NO ACTION.
613 : */
614 : static Datum
615 456 : ri_restrict(TriggerData *trigdata, bool is_no_action)
616 : {
617 : const RI_ConstraintInfo *riinfo;
618 : Relation fk_rel;
619 : Relation pk_rel;
620 : TupleTableSlot *oldslot;
621 : RI_QueryKey qkey;
622 : SPIPlanPtr qplan;
623 :
624 456 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
625 : trigdata->tg_relation, true);
626 :
627 : /*
628 : * Get the relation descriptors of the FK and PK tables and the old tuple.
629 : *
630 : * fk_rel is opened in RowShareLock mode since that's what our eventual
631 : * SELECT FOR KEY SHARE will get on it.
632 : */
633 456 : fk_rel = table_open(riinfo->fk_relid, RowShareLock);
634 456 : pk_rel = trigdata->tg_relation;
635 456 : oldslot = trigdata->tg_trigslot;
636 :
637 : /*
638 : * If another PK row now exists providing the old key values, we should
639 : * not do anything. However, this check should only be made in the NO
640 : * ACTION case; in RESTRICT cases we don't wish to allow another row to be
641 : * substituted.
642 : */
643 888 : if (is_no_action &&
644 432 : ri_Check_Pk_Match(pk_rel, fk_rel, oldslot, riinfo))
645 : {
646 12 : table_close(fk_rel, RowShareLock);
647 12 : return PointerGetDatum(NULL);
648 : }
649 :
650 444 : if (SPI_connect() != SPI_OK_CONNECT)
651 0 : elog(ERROR, "SPI_connect failed");
652 :
653 : /*
654 : * Fetch or prepare a saved plan for the restrict lookup (it's the same
655 : * query for delete and update cases)
656 : */
657 444 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_RESTRICT_CHECKREF);
658 :
659 444 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
660 : {
661 : StringInfoData querybuf;
662 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
663 : char attname[MAX_QUOTED_NAME_LEN];
664 : char paramname[16];
665 : const char *querysep;
666 : Oid queryoids[RI_MAX_NUMKEYS];
667 : const char *fk_only;
668 :
669 : /* ----------
670 : * The query string built is
671 : * SELECT 1 FROM [ONLY] <fktable> x WHERE $1 = fkatt1 [AND ...]
672 : * FOR KEY SHARE OF x
673 : * The type id's for the $ parameters are those of the
674 : * corresponding PK attributes.
675 : * ----------
676 : */
677 210 : initStringInfo(&querybuf);
678 420 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
679 210 : "" : "ONLY ";
680 210 : quoteRelationName(fkrelname, fk_rel);
681 210 : appendStringInfo(&querybuf, "SELECT 1 FROM %s%s x",
682 : fk_only, fkrelname);
683 210 : querysep = "WHERE";
684 484 : for (int i = 0; i < riinfo->nkeys; i++)
685 : {
686 274 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
687 274 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
688 274 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
689 274 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
690 :
691 274 : quoteOneName(attname,
692 274 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
693 274 : sprintf(paramname, "$%d", i + 1);
694 274 : ri_GenerateQual(&querybuf, querysep,
695 : paramname, pk_type,
696 : riinfo->pf_eq_oprs[i],
697 : attname, fk_type);
698 274 : if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
699 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
700 274 : querysep = "AND";
701 274 : queryoids[i] = pk_type;
702 : }
703 210 : appendStringInfoString(&querybuf, " FOR KEY SHARE OF x");
704 :
705 : /* Prepare and save the plan */
706 210 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
707 : &qkey, fk_rel, pk_rel, true);
708 : }
709 :
710 : /*
711 : * We have a plan now. Run it to check for existing references.
712 : */
713 444 : ri_PerformCheck(riinfo, &qkey, qplan,
714 : fk_rel, pk_rel,
715 : oldslot, NULL,
716 : true, /* must detect new rows */
717 : SPI_OK_SELECT);
718 :
719 242 : if (SPI_finish() != SPI_OK_FINISH)
720 0 : elog(ERROR, "SPI_finish failed");
721 :
722 242 : table_close(fk_rel, RowShareLock);
723 :
724 242 : return PointerGetDatum(NULL);
725 : }
726 :
727 :
728 : /*
729 : * RI_FKey_cascade_del -
730 : *
731 : * Cascaded delete foreign key references at delete event on PK table.
732 : */
733 : Datum
734 80 : RI_FKey_cascade_del(PG_FUNCTION_ARGS)
735 : {
736 80 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
737 : const RI_ConstraintInfo *riinfo;
738 : Relation fk_rel;
739 : Relation pk_rel;
740 : TupleTableSlot *oldslot;
741 : RI_QueryKey qkey;
742 : SPIPlanPtr qplan;
743 :
744 : /* Check that this is a valid trigger call on the right time and event. */
745 80 : ri_CheckTrigger(fcinfo, "RI_FKey_cascade_del", RI_TRIGTYPE_DELETE);
746 :
747 80 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
748 : trigdata->tg_relation, true);
749 :
750 : /*
751 : * Get the relation descriptors of the FK and PK tables and the old tuple.
752 : *
753 : * fk_rel is opened in RowExclusiveLock mode since that's what our
754 : * eventual DELETE will get on it.
755 : */
756 80 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
757 80 : pk_rel = trigdata->tg_relation;
758 80 : oldslot = trigdata->tg_trigslot;
759 :
760 80 : if (SPI_connect() != SPI_OK_CONNECT)
761 0 : elog(ERROR, "SPI_connect failed");
762 :
763 : /* Fetch or prepare a saved plan for the cascaded delete */
764 80 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_DEL_DODELETE);
765 :
766 80 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
767 : {
768 : StringInfoData querybuf;
769 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
770 : char attname[MAX_QUOTED_NAME_LEN];
771 : char paramname[16];
772 : const char *querysep;
773 : Oid queryoids[RI_MAX_NUMKEYS];
774 : const char *fk_only;
775 :
776 : /* ----------
777 : * The query string built is
778 : * DELETE FROM [ONLY] <fktable> WHERE $1 = fkatt1 [AND ...]
779 : * The type id's for the $ parameters are those of the
780 : * corresponding PK attributes.
781 : * ----------
782 : */
783 44 : initStringInfo(&querybuf);
784 88 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
785 44 : "" : "ONLY ";
786 44 : quoteRelationName(fkrelname, fk_rel);
787 44 : appendStringInfo(&querybuf, "DELETE FROM %s%s",
788 : fk_only, fkrelname);
789 44 : querysep = "WHERE";
790 100 : for (int i = 0; i < riinfo->nkeys; i++)
791 : {
792 56 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
793 56 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
794 56 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
795 56 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
796 :
797 56 : quoteOneName(attname,
798 56 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
799 56 : sprintf(paramname, "$%d", i + 1);
800 56 : ri_GenerateQual(&querybuf, querysep,
801 : paramname, pk_type,
802 : riinfo->pf_eq_oprs[i],
803 : attname, fk_type);
804 56 : if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
805 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
806 56 : querysep = "AND";
807 56 : queryoids[i] = pk_type;
808 : }
809 :
810 : /* Prepare and save the plan */
811 44 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
812 : &qkey, fk_rel, pk_rel, true);
813 : }
814 :
815 : /*
816 : * We have a plan now. Build up the arguments from the key values in the
817 : * deleted PK tuple and delete the referencing rows
818 : */
819 80 : ri_PerformCheck(riinfo, &qkey, qplan,
820 : fk_rel, pk_rel,
821 : oldslot, NULL,
822 : true, /* must detect new rows */
823 : SPI_OK_DELETE);
824 :
825 80 : if (SPI_finish() != SPI_OK_FINISH)
826 0 : elog(ERROR, "SPI_finish failed");
827 :
828 80 : table_close(fk_rel, RowExclusiveLock);
829 :
830 80 : return PointerGetDatum(NULL);
831 : }
832 :
833 :
834 : /*
835 : * RI_FKey_cascade_upd -
836 : *
837 : * Cascaded update foreign key references at update event on PK table.
838 : */
839 : Datum
840 56 : RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
841 : {
842 56 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
843 : const RI_ConstraintInfo *riinfo;
844 : Relation fk_rel;
845 : Relation pk_rel;
846 : TupleTableSlot *newslot;
847 : TupleTableSlot *oldslot;
848 : RI_QueryKey qkey;
849 : SPIPlanPtr qplan;
850 :
851 : /* Check that this is a valid trigger call on the right time and event. */
852 56 : ri_CheckTrigger(fcinfo, "RI_FKey_cascade_upd", RI_TRIGTYPE_UPDATE);
853 :
854 56 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
855 : trigdata->tg_relation, true);
856 :
857 : /*
858 : * Get the relation descriptors of the FK and PK tables and the new and
859 : * old tuple.
860 : *
861 : * fk_rel is opened in RowExclusiveLock mode since that's what our
862 : * eventual UPDATE will get on it.
863 : */
864 56 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
865 56 : pk_rel = trigdata->tg_relation;
866 56 : newslot = trigdata->tg_newslot;
867 56 : oldslot = trigdata->tg_trigslot;
868 :
869 56 : if (SPI_connect() != SPI_OK_CONNECT)
870 0 : elog(ERROR, "SPI_connect failed");
871 :
872 : /* Fetch or prepare a saved plan for the cascaded update */
873 56 : ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CASCADE_UPD_DOUPDATE);
874 :
875 56 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
876 : {
877 : StringInfoData querybuf;
878 : StringInfoData qualbuf;
879 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
880 : char attname[MAX_QUOTED_NAME_LEN];
881 : char paramname[16];
882 : const char *querysep;
883 : const char *qualsep;
884 : Oid queryoids[RI_MAX_NUMKEYS * 2];
885 : const char *fk_only;
886 :
887 : /* ----------
888 : * The query string built is
889 : * UPDATE [ONLY] <fktable> SET fkatt1 = $1 [, ...]
890 : * WHERE $n = fkatt1 [AND ...]
891 : * The type id's for the $ parameters are those of the
892 : * corresponding PK attributes. Note that we are assuming
893 : * there is an assignment cast from the PK to the FK type;
894 : * else the parser will fail.
895 : * ----------
896 : */
897 44 : initStringInfo(&querybuf);
898 44 : initStringInfo(&qualbuf);
899 88 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
900 44 : "" : "ONLY ";
901 44 : quoteRelationName(fkrelname, fk_rel);
902 44 : appendStringInfo(&querybuf, "UPDATE %s%s SET",
903 : fk_only, fkrelname);
904 44 : querysep = "";
905 44 : qualsep = "WHERE";
906 104 : for (int i = 0, j = riinfo->nkeys; i < riinfo->nkeys; i++, j++)
907 : {
908 60 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
909 60 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
910 60 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
911 60 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
912 :
913 60 : quoteOneName(attname,
914 60 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
915 60 : appendStringInfo(&querybuf,
916 : "%s %s = $%d",
917 : querysep, attname, i + 1);
918 60 : sprintf(paramname, "$%d", j + 1);
919 60 : ri_GenerateQual(&qualbuf, qualsep,
920 : paramname, pk_type,
921 : riinfo->pf_eq_oprs[i],
922 : attname, fk_type);
923 60 : if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
924 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
925 60 : querysep = ",";
926 60 : qualsep = "AND";
927 60 : queryoids[i] = pk_type;
928 60 : queryoids[j] = pk_type;
929 : }
930 44 : appendStringInfoString(&querybuf, qualbuf.data);
931 :
932 : /* Prepare and save the plan */
933 44 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys * 2, queryoids,
934 : &qkey, fk_rel, pk_rel, true);
935 : }
936 :
937 : /*
938 : * We have a plan now. Run it to update the existing references.
939 : */
940 56 : ri_PerformCheck(riinfo, &qkey, qplan,
941 : fk_rel, pk_rel,
942 : oldslot, newslot,
943 : true, /* must detect new rows */
944 : SPI_OK_UPDATE);
945 :
946 56 : if (SPI_finish() != SPI_OK_FINISH)
947 0 : elog(ERROR, "SPI_finish failed");
948 :
949 56 : table_close(fk_rel, RowExclusiveLock);
950 :
951 56 : return PointerGetDatum(NULL);
952 : }
953 :
954 :
955 : /*
956 : * RI_FKey_setnull_del -
957 : *
958 : * Set foreign key references to NULL values at delete event on PK table.
959 : */
960 : Datum
961 52 : RI_FKey_setnull_del(PG_FUNCTION_ARGS)
962 : {
963 : /* Check that this is a valid trigger call on the right time and event. */
964 52 : ri_CheckTrigger(fcinfo, "RI_FKey_setnull_del", RI_TRIGTYPE_DELETE);
965 :
966 : /* Share code with UPDATE case */
967 52 : return ri_set((TriggerData *) fcinfo->context, true);
968 : }
969 :
970 : /*
971 : * RI_FKey_setnull_upd -
972 : *
973 : * Set foreign key references to NULL at update event on PK table.
974 : */
975 : Datum
976 20 : RI_FKey_setnull_upd(PG_FUNCTION_ARGS)
977 : {
978 : /* Check that this is a valid trigger call on the right time and event. */
979 20 : ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
980 :
981 : /* Share code with DELETE case */
982 20 : return ri_set((TriggerData *) fcinfo->context, true);
983 : }
984 :
985 : /*
986 : * RI_FKey_setdefault_del -
987 : *
988 : * Set foreign key references to defaults at delete event on PK table.
989 : */
990 : Datum
991 40 : RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
992 : {
993 : /* Check that this is a valid trigger call on the right time and event. */
994 40 : ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_del", RI_TRIGTYPE_DELETE);
995 :
996 : /* Share code with UPDATE case */
997 40 : return ri_set((TriggerData *) fcinfo->context, false);
998 : }
999 :
1000 : /*
1001 : * RI_FKey_setdefault_upd -
1002 : *
1003 : * Set foreign key references to defaults at update event on PK table.
1004 : */
1005 : Datum
1006 28 : RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
1007 : {
1008 : /* Check that this is a valid trigger call on the right time and event. */
1009 28 : ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
1010 :
1011 : /* Share code with DELETE case */
1012 28 : return ri_set((TriggerData *) fcinfo->context, false);
1013 : }
1014 :
1015 : /*
1016 : * ri_set -
1017 : *
1018 : * Common code for ON DELETE SET NULL, ON DELETE SET DEFAULT, ON UPDATE SET
1019 : * NULL, and ON UPDATE SET DEFAULT.
1020 : */
1021 : static Datum
1022 140 : ri_set(TriggerData *trigdata, bool is_set_null)
1023 : {
1024 : const RI_ConstraintInfo *riinfo;
1025 : Relation fk_rel;
1026 : Relation pk_rel;
1027 : TupleTableSlot *oldslot;
1028 : RI_QueryKey qkey;
1029 : SPIPlanPtr qplan;
1030 :
1031 140 : riinfo = ri_FetchConstraintInfo(trigdata->tg_trigger,
1032 : trigdata->tg_relation, true);
1033 :
1034 : /*
1035 : * Get the relation descriptors of the FK and PK tables and the old tuple.
1036 : *
1037 : * fk_rel is opened in RowExclusiveLock mode since that's what our
1038 : * eventual UPDATE will get on it.
1039 : */
1040 140 : fk_rel = table_open(riinfo->fk_relid, RowExclusiveLock);
1041 140 : pk_rel = trigdata->tg_relation;
1042 140 : oldslot = trigdata->tg_trigslot;
1043 :
1044 140 : if (SPI_connect() != SPI_OK_CONNECT)
1045 0 : elog(ERROR, "SPI_connect failed");
1046 :
1047 : /*
1048 : * Fetch or prepare a saved plan for the set null/default operation (it's
1049 : * the same query for delete and update cases)
1050 : */
1051 140 : ri_BuildQueryKey(&qkey, riinfo,
1052 : (is_set_null
1053 : ? RI_PLAN_SETNULL_DOUPDATE
1054 : : RI_PLAN_SETDEFAULT_DOUPDATE));
1055 :
1056 140 : if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
1057 : {
1058 : StringInfoData querybuf;
1059 : StringInfoData qualbuf;
1060 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1061 : char attname[MAX_QUOTED_NAME_LEN];
1062 : char paramname[16];
1063 : const char *querysep;
1064 : const char *qualsep;
1065 : Oid queryoids[RI_MAX_NUMKEYS];
1066 : const char *fk_only;
1067 :
1068 : /* ----------
1069 : * The query string built is
1070 : * UPDATE [ONLY] <fktable> SET fkatt1 = {NULL|DEFAULT} [, ...]
1071 : * WHERE $1 = fkatt1 [AND ...]
1072 : * The type id's for the $ parameters are those of the
1073 : * corresponding PK attributes.
1074 : * ----------
1075 : */
1076 64 : initStringInfo(&querybuf);
1077 64 : initStringInfo(&qualbuf);
1078 128 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1079 64 : "" : "ONLY ";
1080 64 : quoteRelationName(fkrelname, fk_rel);
1081 64 : appendStringInfo(&querybuf, "UPDATE %s%s SET",
1082 : fk_only, fkrelname);
1083 64 : querysep = "";
1084 64 : qualsep = "WHERE";
1085 176 : for (int i = 0; i < riinfo->nkeys; i++)
1086 : {
1087 112 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1088 112 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1089 112 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
1090 112 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
1091 :
1092 112 : quoteOneName(attname,
1093 112 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1094 112 : appendStringInfo(&querybuf,
1095 : "%s %s = %s",
1096 : querysep, attname,
1097 : is_set_null ? "NULL" : "DEFAULT");
1098 112 : sprintf(paramname, "$%d", i + 1);
1099 112 : ri_GenerateQual(&qualbuf, qualsep,
1100 : paramname, pk_type,
1101 : riinfo->pf_eq_oprs[i],
1102 : attname, fk_type);
1103 112 : if (pk_coll != fk_coll && !get_collation_isdeterministic(pk_coll))
1104 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
1105 112 : querysep = ",";
1106 112 : qualsep = "AND";
1107 112 : queryoids[i] = pk_type;
1108 : }
1109 64 : appendStringInfoString(&querybuf, qualbuf.data);
1110 :
1111 : /* Prepare and save the plan */
1112 64 : qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
1113 : &qkey, fk_rel, pk_rel, true);
1114 : }
1115 :
1116 : /*
1117 : * We have a plan now. Run it to update the existing references.
1118 : */
1119 140 : ri_PerformCheck(riinfo, &qkey, qplan,
1120 : fk_rel, pk_rel,
1121 : oldslot, NULL,
1122 : true, /* must detect new rows */
1123 : SPI_OK_UPDATE);
1124 :
1125 140 : if (SPI_finish() != SPI_OK_FINISH)
1126 0 : elog(ERROR, "SPI_finish failed");
1127 :
1128 140 : table_close(fk_rel, RowExclusiveLock);
1129 :
1130 140 : if (is_set_null)
1131 72 : return PointerGetDatum(NULL);
1132 : else
1133 : {
1134 : /*
1135 : * If we just deleted or updated the PK row whose key was equal to the
1136 : * FK columns' default values, and a referencing row exists in the FK
1137 : * table, we would have updated that row to the same values it already
1138 : * had --- and RI_FKey_fk_upd_check_required would hence believe no
1139 : * check is necessary. So we need to do another lookup now and in
1140 : * case a reference still exists, abort the operation. That is
1141 : * already implemented in the NO ACTION trigger, so just run it. (This
1142 : * recheck is only needed in the SET DEFAULT case, since CASCADE would
1143 : * remove such rows in case of a DELETE operation or would change the
1144 : * FK key values in case of an UPDATE, while SET NULL is certain to
1145 : * result in rows that satisfy the FK constraint.)
1146 : */
1147 68 : return ri_restrict(trigdata, true);
1148 : }
1149 : }
1150 :
1151 :
1152 : /*
1153 : * RI_FKey_pk_upd_check_required -
1154 : *
1155 : * Check if we really need to fire the RI trigger for an update or delete to a PK
1156 : * relation. This is called by the AFTER trigger queue manager to see if
1157 : * it can skip queuing an instance of an RI trigger. Returns true if the
1158 : * trigger must be fired, false if we can prove the constraint will still
1159 : * be satisfied.
1160 : *
1161 : * newslot will be NULL if this is called for a delete.
1162 : */
1163 : bool
1164 1172 : RI_FKey_pk_upd_check_required(Trigger *trigger, Relation pk_rel,
1165 : TupleTableSlot *oldslot, TupleTableSlot *newslot)
1166 : {
1167 : const RI_ConstraintInfo *riinfo;
1168 :
1169 1172 : riinfo = ri_FetchConstraintInfo(trigger, pk_rel, true);
1170 :
1171 : /*
1172 : * If any old key value is NULL, the row could not have been referenced by
1173 : * an FK row, so no check is needed.
1174 : */
1175 1172 : if (ri_NullCheck(RelationGetDescr(pk_rel), oldslot, riinfo, true) != RI_KEYS_NONE_NULL)
1176 4 : return false;
1177 :
1178 : /* If all old and new key values are equal, no check is needed */
1179 1168 : if (newslot && ri_KeysEqual(pk_rel, oldslot, newslot, riinfo, true))
1180 472 : return false;
1181 :
1182 : /* Else we need to fire the trigger. */
1183 696 : return true;
1184 : }
1185 :
1186 : /*
1187 : * RI_FKey_fk_upd_check_required -
1188 : *
1189 : * Check if we really need to fire the RI trigger for an update to an FK
1190 : * relation. This is called by the AFTER trigger queue manager to see if
1191 : * it can skip queuing an instance of an RI trigger. Returns true if the
1192 : * trigger must be fired, false if we can prove the constraint will still
1193 : * be satisfied.
1194 : */
1195 : bool
1196 678 : RI_FKey_fk_upd_check_required(Trigger *trigger, Relation fk_rel,
1197 : TupleTableSlot *oldslot, TupleTableSlot *newslot)
1198 : {
1199 : const RI_ConstraintInfo *riinfo;
1200 : int ri_nullcheck;
1201 : Datum xminDatum;
1202 : TransactionId xmin;
1203 : bool isnull;
1204 :
1205 678 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1206 :
1207 678 : ri_nullcheck = ri_NullCheck(RelationGetDescr(fk_rel), newslot, riinfo, false);
1208 :
1209 : /*
1210 : * If all new key values are NULL, the row satisfies the constraint, so no
1211 : * check is needed.
1212 : */
1213 678 : if (ri_nullcheck == RI_KEYS_ALL_NULL)
1214 84 : return false;
1215 :
1216 : /*
1217 : * If some new key values are NULL, the behavior depends on the match
1218 : * type.
1219 : */
1220 594 : else if (ri_nullcheck == RI_KEYS_SOME_NULL)
1221 : {
1222 8 : switch (riinfo->confmatchtype)
1223 : {
1224 : case FKCONSTR_MATCH_SIMPLE:
1225 :
1226 : /*
1227 : * If any new key value is NULL, the row must satisfy the
1228 : * constraint, so no check is needed.
1229 : */
1230 4 : return false;
1231 :
1232 : case FKCONSTR_MATCH_PARTIAL:
1233 :
1234 : /*
1235 : * Don't know, must run full check.
1236 : */
1237 0 : break;
1238 :
1239 : case FKCONSTR_MATCH_FULL:
1240 :
1241 : /*
1242 : * If some new key values are NULL, the row fails the
1243 : * constraint. We must not throw error here, because the row
1244 : * might get invalidated before the constraint is to be
1245 : * checked, but we should queue the event to apply the check
1246 : * later.
1247 : */
1248 4 : return true;
1249 : }
1250 : }
1251 :
1252 : /*
1253 : * Continues here for no new key values are NULL, or we couldn't decide
1254 : * yet.
1255 : */
1256 :
1257 : /*
1258 : * If the original row was inserted by our own transaction, we must fire
1259 : * the trigger whether or not the keys are equal. This is because our
1260 : * UPDATE will invalidate the INSERT so that the INSERT RI trigger will
1261 : * not do anything; so we had better do the UPDATE check. (We could skip
1262 : * this if we knew the INSERT trigger already fired, but there is no easy
1263 : * way to know that.)
1264 : */
1265 586 : xminDatum = slot_getsysattr(oldslot, MinTransactionIdAttributeNumber, &isnull);
1266 : Assert(!isnull);
1267 586 : xmin = DatumGetTransactionId(xminDatum);
1268 586 : if (TransactionIdIsCurrentTransactionId(xmin))
1269 94 : return true;
1270 :
1271 : /* If all old and new key values are equal, no check is needed */
1272 492 : if (ri_KeysEqual(fk_rel, oldslot, newslot, riinfo, false))
1273 372 : return false;
1274 :
1275 : /* Else we need to fire the trigger. */
1276 120 : return true;
1277 : }
1278 :
1279 : /*
1280 : * RI_Initial_Check -
1281 : *
1282 : * Check an entire table for non-matching values using a single query.
1283 : * This is not a trigger procedure, but is called during ALTER TABLE
1284 : * ADD FOREIGN KEY to validate the initial table contents.
1285 : *
1286 : * We expect that the caller has made provision to prevent any problems
1287 : * caused by concurrent actions. This could be either by locking rel and
1288 : * pkrel at ShareRowExclusiveLock or higher, or by otherwise ensuring
1289 : * that triggers implementing the checks are already active.
1290 : * Hence, we do not need to lock individual rows for the check.
1291 : *
1292 : * If the check fails because the current user doesn't have permissions
1293 : * to read both tables, return false to let our caller know that they will
1294 : * need to do something else to check the constraint.
1295 : */
1296 : bool
1297 632 : RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
1298 : {
1299 : const RI_ConstraintInfo *riinfo;
1300 : StringInfoData querybuf;
1301 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
1302 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1303 : char pkattname[MAX_QUOTED_NAME_LEN + 3];
1304 : char fkattname[MAX_QUOTED_NAME_LEN + 3];
1305 : RangeTblEntry *pkrte;
1306 : RangeTblEntry *fkrte;
1307 : const char *sep;
1308 : const char *fk_only;
1309 : const char *pk_only;
1310 : int save_nestlevel;
1311 : char workmembuf[32];
1312 : int spi_result;
1313 : SPIPlanPtr qplan;
1314 :
1315 632 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1316 :
1317 : /*
1318 : * Check to make sure current user has enough permissions to do the test
1319 : * query. (If not, caller can fall back to the trigger method, which
1320 : * works because it changes user IDs on the fly.)
1321 : *
1322 : * XXX are there any other show-stopper conditions to check?
1323 : */
1324 632 : pkrte = makeNode(RangeTblEntry);
1325 632 : pkrte->rtekind = RTE_RELATION;
1326 632 : pkrte->relid = RelationGetRelid(pk_rel);
1327 632 : pkrte->relkind = pk_rel->rd_rel->relkind;
1328 632 : pkrte->rellockmode = AccessShareLock;
1329 632 : pkrte->requiredPerms = ACL_SELECT;
1330 :
1331 632 : fkrte = makeNode(RangeTblEntry);
1332 632 : fkrte->rtekind = RTE_RELATION;
1333 632 : fkrte->relid = RelationGetRelid(fk_rel);
1334 632 : fkrte->relkind = fk_rel->rd_rel->relkind;
1335 632 : fkrte->rellockmode = AccessShareLock;
1336 632 : fkrte->requiredPerms = ACL_SELECT;
1337 :
1338 1422 : for (int i = 0; i < riinfo->nkeys; i++)
1339 : {
1340 : int attno;
1341 :
1342 790 : attno = riinfo->pk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
1343 790 : pkrte->selectedCols = bms_add_member(pkrte->selectedCols, attno);
1344 :
1345 790 : attno = riinfo->fk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
1346 790 : fkrte->selectedCols = bms_add_member(fkrte->selectedCols, attno);
1347 : }
1348 :
1349 632 : if (!ExecCheckRTPerms(list_make2(fkrte, pkrte), false))
1350 8 : return false;
1351 :
1352 : /*
1353 : * Also punt if RLS is enabled on either table unless this role has the
1354 : * bypassrls right or is the table owner of the table(s) involved which
1355 : * have RLS enabled.
1356 : */
1357 624 : if (!has_bypassrls_privilege(GetUserId()) &&
1358 0 : ((pk_rel->rd_rel->relrowsecurity &&
1359 0 : !pg_class_ownercheck(pkrte->relid, GetUserId())) ||
1360 0 : (fk_rel->rd_rel->relrowsecurity &&
1361 0 : !pg_class_ownercheck(fkrte->relid, GetUserId()))))
1362 0 : return false;
1363 :
1364 : /*----------
1365 : * The query string built is:
1366 : * SELECT fk.keycols FROM [ONLY] relname fk
1367 : * LEFT OUTER JOIN [ONLY] pkrelname pk
1368 : * ON (pk.pkkeycol1=fk.keycol1 [AND ...])
1369 : * WHERE pk.pkkeycol1 IS NULL AND
1370 : * For MATCH SIMPLE:
1371 : * (fk.keycol1 IS NOT NULL [AND ...])
1372 : * For MATCH FULL:
1373 : * (fk.keycol1 IS NOT NULL [OR ...])
1374 : *
1375 : * We attach COLLATE clauses to the operators when comparing columns
1376 : * that have different collations.
1377 : *----------
1378 : */
1379 624 : initStringInfo(&querybuf);
1380 624 : appendStringInfoString(&querybuf, "SELECT ");
1381 624 : sep = "";
1382 1398 : for (int i = 0; i < riinfo->nkeys; i++)
1383 : {
1384 774 : quoteOneName(fkattname,
1385 774 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1386 774 : appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
1387 774 : sep = ", ";
1388 : }
1389 :
1390 624 : quoteRelationName(pkrelname, pk_rel);
1391 624 : quoteRelationName(fkrelname, fk_rel);
1392 1248 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1393 624 : "" : "ONLY ";
1394 1248 : pk_only = pk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1395 624 : "" : "ONLY ";
1396 624 : appendStringInfo(&querybuf,
1397 : " FROM %s%s fk LEFT OUTER JOIN %s%s pk ON",
1398 : fk_only, fkrelname, pk_only, pkrelname);
1399 :
1400 624 : strcpy(pkattname, "pk.");
1401 624 : strcpy(fkattname, "fk.");
1402 624 : sep = "(";
1403 1398 : for (int i = 0; i < riinfo->nkeys; i++)
1404 : {
1405 774 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1406 774 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1407 774 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
1408 774 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
1409 :
1410 774 : quoteOneName(pkattname + 3,
1411 774 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
1412 774 : quoteOneName(fkattname + 3,
1413 774 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1414 774 : ri_GenerateQual(&querybuf, sep,
1415 : pkattname, pk_type,
1416 : riinfo->pf_eq_oprs[i],
1417 : fkattname, fk_type);
1418 774 : if (pk_coll != fk_coll)
1419 8 : ri_GenerateQualCollation(&querybuf, pk_coll);
1420 774 : sep = "AND";
1421 : }
1422 :
1423 : /*
1424 : * It's sufficient to test any one pk attribute for null to detect a join
1425 : * failure.
1426 : */
1427 624 : quoteOneName(pkattname, RIAttName(pk_rel, riinfo->pk_attnums[0]));
1428 624 : appendStringInfo(&querybuf, ") WHERE pk.%s IS NULL AND (", pkattname);
1429 :
1430 624 : sep = "";
1431 1398 : for (int i = 0; i < riinfo->nkeys; i++)
1432 : {
1433 774 : quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
1434 774 : appendStringInfo(&querybuf,
1435 : "%sfk.%s IS NOT NULL",
1436 : sep, fkattname);
1437 774 : switch (riinfo->confmatchtype)
1438 : {
1439 : case FKCONSTR_MATCH_SIMPLE:
1440 706 : sep = " AND ";
1441 706 : break;
1442 : case FKCONSTR_MATCH_FULL:
1443 68 : sep = " OR ";
1444 68 : break;
1445 : }
1446 : }
1447 624 : appendStringInfoChar(&querybuf, ')');
1448 :
1449 : /*
1450 : * Temporarily increase work_mem so that the check query can be executed
1451 : * more efficiently. It seems okay to do this because the query is simple
1452 : * enough to not use a multiple of work_mem, and one typically would not
1453 : * have many large foreign-key validations happening concurrently. So
1454 : * this seems to meet the criteria for being considered a "maintenance"
1455 : * operation, and accordingly we use maintenance_work_mem.
1456 : *
1457 : * We use the equivalent of a function SET option to allow the setting to
1458 : * persist for exactly the duration of the check query. guc.c also takes
1459 : * care of undoing the setting on error.
1460 : */
1461 624 : save_nestlevel = NewGUCNestLevel();
1462 :
1463 624 : snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
1464 624 : (void) set_config_option("work_mem", workmembuf,
1465 : PGC_USERSET, PGC_S_SESSION,
1466 : GUC_ACTION_SAVE, true, 0, false);
1467 :
1468 624 : if (SPI_connect() != SPI_OK_CONNECT)
1469 0 : elog(ERROR, "SPI_connect failed");
1470 :
1471 : /*
1472 : * Generate the plan. We don't need to cache it, and there are no
1473 : * arguments to the plan.
1474 : */
1475 624 : qplan = SPI_prepare(querybuf.data, 0, NULL);
1476 :
1477 624 : if (qplan == NULL)
1478 0 : elog(ERROR, "SPI_prepare returned %s for %s",
1479 : SPI_result_code_string(SPI_result), querybuf.data);
1480 :
1481 : /*
1482 : * Run the plan. For safety we force a current snapshot to be used. (In
1483 : * transaction-snapshot mode, this arguably violates transaction isolation
1484 : * rules, but we really haven't got much choice.) We don't need to
1485 : * register the snapshot, because SPI_execute_snapshot will see to it. We
1486 : * need at most one tuple returned, so pass limit = 1.
1487 : */
1488 624 : spi_result = SPI_execute_snapshot(qplan,
1489 : NULL, NULL,
1490 : GetLatestSnapshot(),
1491 : InvalidSnapshot,
1492 : true, false, 1);
1493 :
1494 : /* Check result */
1495 624 : if (spi_result != SPI_OK_SELECT)
1496 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
1497 :
1498 : /* Did we find a tuple violating the constraint? */
1499 624 : if (SPI_processed > 0)
1500 : {
1501 : TupleTableSlot *slot;
1502 42 : HeapTuple tuple = SPI_tuptable->vals[0];
1503 42 : TupleDesc tupdesc = SPI_tuptable->tupdesc;
1504 : RI_ConstraintInfo fake_riinfo;
1505 :
1506 42 : slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
1507 :
1508 42 : heap_deform_tuple(tuple, tupdesc,
1509 : slot->tts_values, slot->tts_isnull);
1510 42 : ExecStoreVirtualTuple(slot);
1511 :
1512 : /*
1513 : * The columns to look at in the result tuple are 1..N, not whatever
1514 : * they are in the fk_rel. Hack up riinfo so that the subroutines
1515 : * called here will behave properly.
1516 : *
1517 : * In addition to this, we have to pass the correct tupdesc to
1518 : * ri_ReportViolation, overriding its normal habit of using the pk_rel
1519 : * or fk_rel's tupdesc.
1520 : */
1521 42 : memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
1522 96 : for (int i = 0; i < fake_riinfo.nkeys; i++)
1523 54 : fake_riinfo.fk_attnums[i] = i + 1;
1524 :
1525 : /*
1526 : * If it's MATCH FULL, and there are any nulls in the FK keys,
1527 : * complain about that rather than the lack of a match. MATCH FULL
1528 : * disallows partially-null FK rows.
1529 : */
1530 58 : if (fake_riinfo.confmatchtype == FKCONSTR_MATCH_FULL &&
1531 16 : ri_NullCheck(tupdesc, slot, &fake_riinfo, false) != RI_KEYS_NONE_NULL)
1532 8 : ereport(ERROR,
1533 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
1534 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
1535 : RelationGetRelationName(fk_rel),
1536 : NameStr(fake_riinfo.conname)),
1537 : errdetail("MATCH FULL does not allow mixing of null and nonnull key values."),
1538 : errtableconstraint(fk_rel,
1539 : NameStr(fake_riinfo.conname))));
1540 :
1541 : /*
1542 : * We tell ri_ReportViolation we were doing the RI_PLAN_CHECK_LOOKUPPK
1543 : * query, which isn't true, but will cause it to use
1544 : * fake_riinfo.fk_attnums as we need.
1545 : */
1546 34 : ri_ReportViolation(&fake_riinfo,
1547 : pk_rel, fk_rel,
1548 : slot, tupdesc,
1549 : RI_PLAN_CHECK_LOOKUPPK, false);
1550 :
1551 : ExecDropSingleTupleTableSlot(slot);
1552 : }
1553 :
1554 582 : if (SPI_finish() != SPI_OK_FINISH)
1555 0 : elog(ERROR, "SPI_finish failed");
1556 :
1557 : /*
1558 : * Restore work_mem.
1559 : */
1560 582 : AtEOXact_GUC(true, save_nestlevel);
1561 :
1562 582 : return true;
1563 : }
1564 :
1565 : /*
1566 : * RI_PartitionRemove_Check -
1567 : *
1568 : * Verify no referencing values exist, when a partition is detached on
1569 : * the referenced side of a foreign key constraint.
1570 : */
1571 : void
1572 24 : RI_PartitionRemove_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
1573 : {
1574 : const RI_ConstraintInfo *riinfo;
1575 : StringInfoData querybuf;
1576 : char *constraintDef;
1577 : char pkrelname[MAX_QUOTED_REL_NAME_LEN];
1578 : char fkrelname[MAX_QUOTED_REL_NAME_LEN];
1579 : char pkattname[MAX_QUOTED_NAME_LEN + 3];
1580 : char fkattname[MAX_QUOTED_NAME_LEN + 3];
1581 : const char *sep;
1582 : const char *fk_only;
1583 : int save_nestlevel;
1584 : char workmembuf[32];
1585 : int spi_result;
1586 : SPIPlanPtr qplan;
1587 : int i;
1588 :
1589 24 : riinfo = ri_FetchConstraintInfo(trigger, fk_rel, false);
1590 :
1591 : /*
1592 : * We don't check permissions before displaying the error message, on the
1593 : * assumption that the user detaching the partition must have enough
1594 : * privileges to examine the table contents anyhow.
1595 : */
1596 :
1597 : /*----------
1598 : * The query string built is:
1599 : * SELECT fk.keycols FROM [ONLY] relname fk
1600 : * JOIN pkrelname pk
1601 : * ON (pk.pkkeycol1=fk.keycol1 [AND ...])
1602 : * WHERE (<partition constraint>) AND
1603 : * For MATCH SIMPLE:
1604 : * (fk.keycol1 IS NOT NULL [AND ...])
1605 : * For MATCH FULL:
1606 : * (fk.keycol1 IS NOT NULL [OR ...])
1607 : *
1608 : * We attach COLLATE clauses to the operators when comparing columns
1609 : * that have different collations.
1610 : *----------
1611 : */
1612 24 : initStringInfo(&querybuf);
1613 24 : appendStringInfoString(&querybuf, "SELECT ");
1614 24 : sep = "";
1615 48 : for (i = 0; i < riinfo->nkeys; i++)
1616 : {
1617 24 : quoteOneName(fkattname,
1618 24 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1619 24 : appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
1620 24 : sep = ", ";
1621 : }
1622 :
1623 24 : quoteRelationName(pkrelname, pk_rel);
1624 24 : quoteRelationName(fkrelname, fk_rel);
1625 48 : fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
1626 24 : "" : "ONLY ";
1627 24 : appendStringInfo(&querybuf,
1628 : " FROM %s%s fk JOIN %s pk ON",
1629 : fk_only, fkrelname, pkrelname);
1630 24 : strcpy(pkattname, "pk.");
1631 24 : strcpy(fkattname, "fk.");
1632 24 : sep = "(";
1633 48 : for (i = 0; i < riinfo->nkeys; i++)
1634 : {
1635 24 : Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
1636 24 : Oid fk_type = RIAttType(fk_rel, riinfo->fk_attnums[i]);
1637 24 : Oid pk_coll = RIAttCollation(pk_rel, riinfo->pk_attnums[i]);
1638 24 : Oid fk_coll = RIAttCollation(fk_rel, riinfo->fk_attnums[i]);
1639 :
1640 24 : quoteOneName(pkattname + 3,
1641 24 : RIAttName(pk_rel, riinfo->pk_attnums[i]));
1642 24 : quoteOneName(fkattname + 3,
1643 24 : RIAttName(fk_rel, riinfo->fk_attnums[i]));
1644 24 : ri_GenerateQual(&querybuf, sep,
1645 : pkattname, pk_type,
1646 : riinfo->pf_eq_oprs[i],
1647 : fkattname, fk_type);
1648 24 : if (pk_coll != fk_coll)
1649 0 : ri_GenerateQualCollation(&querybuf, pk_coll);
1650 24 : sep = "AND";
1651 : }
1652 :
1653 : /*
1654 : * Start the WHERE clause with the partition constraint (except if this is
1655 : * the default partition and there's no other partition, because the
1656 : * partition constraint is the empty string in that case.)
1657 : */
1658 24 : constraintDef = pg_get_partconstrdef_string(RelationGetRelid(pk_rel), "pk");
1659 24 : if (constraintDef && constraintDef[0] != '\0')
1660 24 : appendStringInfo(&querybuf, ") WHERE %s AND (",
1661 : constraintDef);
1662 : else
1663 0 : appendStringInfo(&querybuf, ") WHERE (");
1664 :
1665 24 : sep = "";
1666 48 : for (i = 0; i < riinfo->nkeys; i++)
1667 : {
1668 24 : quoteOneName(fkattname, RIAttName(fk_rel, riinfo->fk_attnums[i]));
1669 24 : appendStringInfo(&querybuf,
1670 : "%sfk.%s IS NOT NULL",
1671 : sep, fkattname);
1672 24 : switch (riinfo->confmatchtype)
1673 : {
1674 : case FKCONSTR_MATCH_SIMPLE:
1675 24 : sep = " AND ";
1676 24 : break;
1677 : case FKCONSTR_MATCH_FULL:
1678 0 : sep = " OR ";
1679 0 : break;
1680 : }
1681 : }
1682 24 : appendStringInfoChar(&querybuf, ')');
1683 :
1684 : /*
1685 : * Temporarily increase work_mem so that the check query can be executed
1686 : * more efficiently. It seems okay to do this because the query is simple
1687 : * enough to not use a multiple of work_mem, and one typically would not
1688 : * have many large foreign-key validations happening concurrently. So
1689 : * this seems to meet the criteria for being considered a "maintenance"
1690 : * operation, and accordingly we use maintenance_work_mem.
1691 : *
1692 : * We use the equivalent of a function SET option to allow the setting to
1693 : * persist for exactly the duration of the check query. guc.c also takes
1694 : * care of undoing the setting on error.
1695 : */
1696 24 : save_nestlevel = NewGUCNestLevel();
1697 :
1698 24 : snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
1699 24 : (void) set_config_option("work_mem", workmembuf,
1700 : PGC_USERSET, PGC_S_SESSION,
1701 : GUC_ACTION_SAVE, true, 0, false);
1702 :
1703 24 : if (SPI_connect() != SPI_OK_CONNECT)
1704 0 : elog(ERROR, "SPI_connect failed");
1705 :
1706 : /*
1707 : * Generate the plan. We don't need to cache it, and there are no
1708 : * arguments to the plan.
1709 : */
1710 24 : qplan = SPI_prepare(querybuf.data, 0, NULL);
1711 :
1712 24 : if (qplan == NULL)
1713 0 : elog(ERROR, "SPI_prepare returned %s for %s",
1714 : SPI_result_code_string(SPI_result), querybuf.data);
1715 :
1716 : /*
1717 : * Run the plan. For safety we force a current snapshot to be used. (In
1718 : * transaction-snapshot mode, this arguably violates transaction isolation
1719 : * rules, but we really haven't got much choice.) We don't need to
1720 : * register the snapshot, because SPI_execute_snapshot will see to it. We
1721 : * need at most one tuple returned, so pass limit = 1.
1722 : */
1723 24 : spi_result = SPI_execute_snapshot(qplan,
1724 : NULL, NULL,
1725 : GetLatestSnapshot(),
1726 : InvalidSnapshot,
1727 : true, false, 1);
1728 :
1729 : /* Check result */
1730 24 : if (spi_result != SPI_OK_SELECT)
1731 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
1732 :
1733 : /* Did we find a tuple that would violate the constraint? */
1734 24 : if (SPI_processed > 0)
1735 : {
1736 : TupleTableSlot *slot;
1737 20 : HeapTuple tuple = SPI_tuptable->vals[0];
1738 20 : TupleDesc tupdesc = SPI_tuptable->tupdesc;
1739 : RI_ConstraintInfo fake_riinfo;
1740 :
1741 20 : slot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
1742 :
1743 20 : heap_deform_tuple(tuple, tupdesc,
1744 : slot->tts_values, slot->tts_isnull);
1745 20 : ExecStoreVirtualTuple(slot);
1746 :
1747 : /*
1748 : * The columns to look at in the result tuple are 1..N, not whatever
1749 : * they are in the fk_rel. Hack up riinfo so that ri_ReportViolation
1750 : * will behave properly.
1751 : *
1752 : * In addition to this, we have to pass the correct tupdesc to
1753 : * ri_ReportViolation, overriding its normal habit of using the pk_rel
1754 : * or fk_rel's tupdesc.
1755 : */
1756 20 : memcpy(&fake_riinfo, riinfo, sizeof(RI_ConstraintInfo));
1757 40 : for (i = 0; i < fake_riinfo.nkeys; i++)
1758 20 : fake_riinfo.pk_attnums[i] = i + 1;
1759 :
1760 20 : ri_ReportViolation(&fake_riinfo, pk_rel, fk_rel,
1761 : slot, tupdesc, 0, true);
1762 : }
1763 :
1764 4 : if (SPI_finish() != SPI_OK_FINISH)
1765 0 : elog(ERROR, "SPI_finish failed");
1766 :
1767 : /*
1768 : * Restore work_mem.
1769 : */
1770 4 : AtEOXact_GUC(true, save_nestlevel);
1771 4 : }
1772 :
1773 :
1774 : /* ----------
1775 : * Local functions below
1776 : * ----------
1777 : */
1778 :
1779 :
1780 : /*
1781 : * quoteOneName --- safely quote a single SQL name
1782 : *
1783 : * buffer must be MAX_QUOTED_NAME_LEN long (includes room for \0)
1784 : */
1785 : static void
1786 13214 : quoteOneName(char *buffer, const char *name)
1787 : {
1788 : /* Rather than trying to be smart, just always quote it. */
1789 13214 : *buffer++ = '"';
1790 92308 : while (*name)
1791 : {
1792 65880 : if (*name == '"')
1793 0 : *buffer++ = '"';
1794 65880 : *buffer++ = *name++;
1795 : }
1796 13214 : *buffer++ = '"';
1797 13214 : *buffer = '\0';
1798 13214 : }
1799 :
1800 : /*
1801 : * quoteRelationName --- safely quote a fully qualified relation name
1802 : *
1803 : * buffer must be MAX_QUOTED_REL_NAME_LEN long (includes room for \0)
1804 : */
1805 : static void
1806 3448 : quoteRelationName(char *buffer, Relation rel)
1807 : {
1808 3448 : quoteOneName(buffer, get_namespace_name(RelationGetNamespace(rel)));
1809 3448 : buffer += strlen(buffer);
1810 3448 : *buffer++ = '.';
1811 3448 : quoteOneName(buffer, RelationGetRelationName(rel));
1812 3448 : }
1813 :
1814 : /*
1815 : * ri_GenerateQual --- generate a WHERE clause equating two variables
1816 : *
1817 : * This basically appends " sep leftop op rightop" to buf, adding casts
1818 : * and schema qualification as needed to ensure that the parser will select
1819 : * the operator we specify. leftop and rightop should be parenthesized
1820 : * if they aren't variables or parameters.
1821 : */
1822 : static void
1823 3284 : ri_GenerateQual(StringInfo buf,
1824 : const char *sep,
1825 : const char *leftop, Oid leftoptype,
1826 : Oid opoid,
1827 : const char *rightop, Oid rightoptype)
1828 : {
1829 3284 : appendStringInfo(buf, " %s ", sep);
1830 3284 : generate_operator_clause(buf, leftop, leftoptype, opoid,
1831 : rightop, rightoptype);
1832 3284 : }
1833 :
1834 : /*
1835 : * ri_GenerateQualCollation --- add a COLLATE spec to a WHERE clause
1836 : *
1837 : * At present, we intentionally do not use this function for RI queries that
1838 : * compare a variable to a $n parameter. Since parameter symbols always have
1839 : * default collation, the effect will be to use the variable's collation.
1840 : * Now that is only strictly correct when testing the referenced column, since
1841 : * the SQL standard specifies that RI comparisons should use the referenced
1842 : * column's collation. However, so long as all collations have the same
1843 : * notion of equality (which they do, because texteq reduces to bitwise
1844 : * equality), there's no visible semantic impact from using the referencing
1845 : * column's collation when testing it, and this is a good thing to do because
1846 : * it lets us use a normal index on the referencing column. However, we do
1847 : * have to use this function when directly comparing the referencing and
1848 : * referenced columns, if they are of different collations; else the parser
1849 : * will fail to resolve the collation to use.
1850 : */
1851 : static void
1852 8 : ri_GenerateQualCollation(StringInfo buf, Oid collation)
1853 : {
1854 : HeapTuple tp;
1855 : Form_pg_collation colltup;
1856 : char *collname;
1857 : char onename[MAX_QUOTED_NAME_LEN];
1858 :
1859 : /* Nothing to do if it's a noncollatable data type */
1860 8 : if (!OidIsValid(collation))
1861 0 : return;
1862 :
1863 8 : tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
1864 8 : if (!HeapTupleIsValid(tp))
1865 0 : elog(ERROR, "cache lookup failed for collation %u", collation);
1866 8 : colltup = (Form_pg_collation) GETSTRUCT(tp);
1867 8 : collname = NameStr(colltup->collname);
1868 :
1869 : /*
1870 : * We qualify the name always, for simplicity and to ensure the query is
1871 : * not search-path-dependent.
1872 : */
1873 8 : quoteOneName(onename, get_namespace_name(colltup->collnamespace));
1874 8 : appendStringInfo(buf, " COLLATE %s", onename);
1875 8 : quoteOneName(onename, collname);
1876 8 : appendStringInfo(buf, ".%s", onename);
1877 :
1878 8 : ReleaseSysCache(tp);
1879 : }
1880 :
1881 : /* ----------
1882 : * ri_BuildQueryKey -
1883 : *
1884 : * Construct a hashtable key for a prepared SPI plan of an FK constraint.
1885 : *
1886 : * key: output argument, *key is filled in based on the other arguments
1887 : * riinfo: info from pg_constraint entry
1888 : * constr_queryno: an internal number identifying the query type
1889 : * (see RI_PLAN_XXX constants at head of file)
1890 : * ----------
1891 : */
1892 : static void
1893 3666 : ri_BuildQueryKey(RI_QueryKey *key, const RI_ConstraintInfo *riinfo,
1894 : int32 constr_queryno)
1895 : {
1896 : /*
1897 : * We assume struct RI_QueryKey contains no padding bytes, else we'd need
1898 : * to use memset to clear them.
1899 : */
1900 3666 : key->constr_id = riinfo->constraint_id;
1901 3666 : key->constr_queryno = constr_queryno;
1902 3666 : }
1903 :
1904 : /*
1905 : * Check that RI trigger function was called in expected context
1906 : */
1907 : static void
1908 3402 : ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname, int tgkind)
1909 : {
1910 3402 : TriggerData *trigdata = (TriggerData *) fcinfo->context;
1911 :
1912 3402 : if (!CALLED_AS_TRIGGER(fcinfo))
1913 0 : ereport(ERROR,
1914 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1915 : errmsg("function \"%s\" was not called by trigger manager", funcname)));
1916 :
1917 : /*
1918 : * Check proper event
1919 : */
1920 6804 : if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
1921 3402 : !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
1922 0 : ereport(ERROR,
1923 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1924 : errmsg("function \"%s\" must be fired AFTER ROW", funcname)));
1925 :
1926 3402 : switch (tgkind)
1927 : {
1928 : case RI_TRIGTYPE_INSERT:
1929 2524 : if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
1930 0 : ereport(ERROR,
1931 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1932 : errmsg("function \"%s\" must be fired for INSERT", funcname)));
1933 2524 : break;
1934 : case RI_TRIGTYPE_UPDATE:
1935 482 : if (!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
1936 0 : ereport(ERROR,
1937 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1938 : errmsg("function \"%s\" must be fired for UPDATE", funcname)));
1939 482 : break;
1940 : case RI_TRIGTYPE_DELETE:
1941 396 : if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
1942 0 : ereport(ERROR,
1943 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1944 : errmsg("function \"%s\" must be fired for DELETE", funcname)));
1945 396 : break;
1946 : }
1947 3402 : }
1948 :
1949 :
1950 : /*
1951 : * Fetch the RI_ConstraintInfo struct for the trigger's FK constraint.
1952 : */
1953 : static const RI_ConstraintInfo *
1954 5976 : ri_FetchConstraintInfo(Trigger *trigger, Relation trig_rel, bool rel_is_pk)
1955 : {
1956 5976 : Oid constraintOid = trigger->tgconstraint;
1957 : const RI_ConstraintInfo *riinfo;
1958 :
1959 : /*
1960 : * Check that the FK constraint's OID is available; it might not be if
1961 : * we've been invoked via an ordinary trigger or an old-style "constraint
1962 : * trigger".
1963 : */
1964 5976 : if (!OidIsValid(constraintOid))
1965 0 : ereport(ERROR,
1966 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
1967 : errmsg("no pg_constraint entry for trigger \"%s\" on table \"%s\"",
1968 : trigger->tgname, RelationGetRelationName(trig_rel)),
1969 : errhint("Remove this referential integrity trigger and its mates, then do ALTER TABLE ADD CONSTRAINT.")));
1970 :
1971 : /* Find or create a hashtable entry for the constraint */
1972 5976 : riinfo = ri_LoadConstraintInfo(constraintOid);
1973 :
1974 : /* Do some easy cross-checks against the trigger call data */
1975 5976 : if (rel_is_pk)
1976 : {
1977 3808 : if (riinfo->fk_relid != trigger->tgconstrrelid ||
1978 1904 : riinfo->pk_relid != RelationGetRelid(trig_rel))
1979 0 : elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
1980 : trigger->tgname, RelationGetRelationName(trig_rel));
1981 : }
1982 : else
1983 : {
1984 8144 : if (riinfo->fk_relid != RelationGetRelid(trig_rel) ||
1985 4072 : riinfo->pk_relid != trigger->tgconstrrelid)
1986 0 : elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
1987 : trigger->tgname, RelationGetRelationName(trig_rel));
1988 : }
1989 :
1990 11642 : if (riinfo->confmatchtype != FKCONSTR_MATCH_FULL &&
1991 11332 : riinfo->confmatchtype != FKCONSTR_MATCH_PARTIAL &&
1992 5666 : riinfo->confmatchtype != FKCONSTR_MATCH_SIMPLE)
1993 0 : elog(ERROR, "unrecognized confmatchtype: %d",
1994 : riinfo->confmatchtype);
1995 :
1996 5976 : if (riinfo->confmatchtype == FKCONSTR_MATCH_PARTIAL)
1997 0 : ereport(ERROR,
1998 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1999 : errmsg("MATCH PARTIAL not yet implemented")));
2000 :
2001 5976 : return riinfo;
2002 : }
2003 :
2004 : /*
2005 : * Fetch or create the RI_ConstraintInfo struct for an FK constraint.
2006 : */
2007 : static const RI_ConstraintInfo *
2008 5976 : ri_LoadConstraintInfo(Oid constraintOid)
2009 : {
2010 : RI_ConstraintInfo *riinfo;
2011 : bool found;
2012 : HeapTuple tup;
2013 : Form_pg_constraint conForm;
2014 :
2015 : /*
2016 : * On the first call initialize the hashtable
2017 : */
2018 5976 : if (!ri_constraint_cache)
2019 344 : ri_InitHashTables();
2020 :
2021 : /*
2022 : * Find or create a hash entry. If we find a valid one, just return it.
2023 : */
2024 5976 : riinfo = (RI_ConstraintInfo *) hash_search(ri_constraint_cache,
2025 : (void *) &constraintOid,
2026 : HASH_ENTER, &found);
2027 5976 : if (!found)
2028 2494 : riinfo->valid = false;
2029 3482 : else if (riinfo->valid)
2030 3398 : return riinfo;
2031 :
2032 : /*
2033 : * Fetch the pg_constraint row so we can fill in the entry.
2034 : */
2035 2578 : tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
2036 2578 : if (!HeapTupleIsValid(tup)) /* should not happen */
2037 0 : elog(ERROR, "cache lookup failed for constraint %u", constraintOid);
2038 2578 : conForm = (Form_pg_constraint) GETSTRUCT(tup);
2039 :
2040 2578 : if (conForm->contype != CONSTRAINT_FOREIGN) /* should not happen */
2041 0 : elog(ERROR, "constraint %u is not a foreign key constraint",
2042 : constraintOid);
2043 :
2044 : /* And extract data */
2045 : Assert(riinfo->constraint_id == constraintOid);
2046 2578 : riinfo->oidHashValue = GetSysCacheHashValue1(CONSTROID,
2047 : ObjectIdGetDatum(constraintOid));
2048 2578 : memcpy(&riinfo->conname, &conForm->conname, sizeof(NameData));
2049 2578 : riinfo->pk_relid = conForm->confrelid;
2050 2578 : riinfo->fk_relid = conForm->conrelid;
2051 2578 : riinfo->confupdtype = conForm->confupdtype;
2052 2578 : riinfo->confdeltype = conForm->confdeltype;
2053 2578 : riinfo->confmatchtype = conForm->confmatchtype;
2054 :
2055 2578 : DeconstructFkConstraintRow(tup,
2056 : &riinfo->nkeys,
2057 2578 : riinfo->fk_attnums,
2058 2578 : riinfo->pk_attnums,
2059 2578 : riinfo->pf_eq_oprs,
2060 2578 : riinfo->pp_eq_oprs,
2061 2578 : riinfo->ff_eq_oprs);
2062 :
2063 2578 : ReleaseSysCache(tup);
2064 :
2065 : /*
2066 : * For efficient processing of invalidation messages below, we keep a
2067 : * doubly-linked list, and a count, of all currently valid entries.
2068 : */
2069 2578 : dlist_push_tail(&ri_constraint_cache_valid_list, &riinfo->valid_link);
2070 2578 : ri_constraint_cache_valid_count++;
2071 :
2072 2578 : riinfo->valid = true;
2073 :
2074 2578 : return riinfo;
2075 : }
2076 :
2077 : /*
2078 : * Callback for pg_constraint inval events
2079 : *
2080 : * While most syscache callbacks just flush all their entries, pg_constraint
2081 : * gets enough update traffic that it's probably worth being smarter.
2082 : * Invalidate any ri_constraint_cache entry associated with the syscache
2083 : * entry with the specified hash value, or all entries if hashvalue == 0.
2084 : *
2085 : * Note: at the time a cache invalidation message is processed there may be
2086 : * active references to the cache. Because of this we never remove entries
2087 : * from the cache, but only mark them invalid, which is harmless to active
2088 : * uses. (Any query using an entry should hold a lock sufficient to keep that
2089 : * data from changing under it --- but we may get cache flushes anyway.)
2090 : */
2091 : static void
2092 17654 : InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)
2093 : {
2094 : dlist_mutable_iter iter;
2095 :
2096 : Assert(ri_constraint_cache != NULL);
2097 :
2098 : /*
2099 : * If the list of currently valid entries gets excessively large, we mark
2100 : * them all invalid so we can empty the list. This arrangement avoids
2101 : * O(N^2) behavior in situations where a session touches many foreign keys
2102 : * and also does many ALTER TABLEs, such as a restore from pg_dump.
2103 : */
2104 17654 : if (ri_constraint_cache_valid_count > 1000)
2105 0 : hashvalue = 0; /* pretend it's a cache reset */
2106 :
2107 50028 : dlist_foreach_modify(iter, &ri_constraint_cache_valid_list)
2108 : {
2109 32374 : RI_ConstraintInfo *riinfo = dlist_container(RI_ConstraintInfo,
2110 : valid_link, iter.cur);
2111 :
2112 32374 : if (hashvalue == 0 || riinfo->oidHashValue == hashvalue)
2113 : {
2114 1552 : riinfo->valid = false;
2115 : /* Remove invalidated entries from the list, too */
2116 1552 : dlist_delete(iter.cur);
2117 1552 : ri_constraint_cache_valid_count--;
2118 : }
2119 : }
2120 17654 : }
2121 :
2122 :
2123 : /*
2124 : * Prepare execution plan for a query to enforce an RI restriction
2125 : *
2126 : * If cache_plan is true, the plan is saved into our plan hashtable
2127 : * so that we don't need to plan it again.
2128 : */
2129 : static SPIPlanPtr
2130 2152 : ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
2131 : RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel,
2132 : bool cache_plan)
2133 : {
2134 : SPIPlanPtr qplan;
2135 : Relation query_rel;
2136 : Oid save_userid;
2137 : int save_sec_context;
2138 :
2139 : /*
2140 : * Use the query type code to determine whether the query is run against
2141 : * the PK or FK table; we'll do the check as that table's owner
2142 : */
2143 2152 : if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
2144 1790 : query_rel = pk_rel;
2145 : else
2146 362 : query_rel = fk_rel;
2147 :
2148 : /* Switch to proper UID to perform check as */
2149 2152 : GetUserIdAndSecContext(&save_userid, &save_sec_context);
2150 2152 : SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
2151 : save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
2152 : SECURITY_NOFORCE_RLS);
2153 :
2154 : /* Create the plan */
2155 2152 : qplan = SPI_prepare(querystr, nargs, argtypes);
2156 :
2157 2152 : if (qplan == NULL)
2158 0 : elog(ERROR, "SPI_prepare returned %s for %s", SPI_result_code_string(SPI_result), querystr);
2159 :
2160 : /* Restore UID and security context */
2161 2152 : SetUserIdAndSecContext(save_userid, save_sec_context);
2162 :
2163 : /* Save the plan if requested */
2164 2152 : if (cache_plan)
2165 : {
2166 2152 : SPI_keepplan(qplan);
2167 2152 : ri_HashPreparedPlan(qkey, qplan);
2168 : }
2169 :
2170 2152 : return qplan;
2171 : }
2172 :
2173 : /*
2174 : * Perform a query to enforce an RI restriction
2175 : */
2176 : static bool
2177 3666 : ri_PerformCheck(const RI_ConstraintInfo *riinfo,
2178 : RI_QueryKey *qkey, SPIPlanPtr qplan,
2179 : Relation fk_rel, Relation pk_rel,
2180 : TupleTableSlot *oldslot, TupleTableSlot *newslot,
2181 : bool detectNewRows, int expect_OK)
2182 : {
2183 : Relation query_rel,
2184 : source_rel;
2185 : bool source_is_pk;
2186 : Snapshot test_snapshot;
2187 : Snapshot crosscheck_snapshot;
2188 : int limit;
2189 : int spi_result;
2190 : Oid save_userid;
2191 : int save_sec_context;
2192 : Datum vals[RI_MAX_NUMKEYS * 2];
2193 : char nulls[RI_MAX_NUMKEYS * 2];
2194 :
2195 : /*
2196 : * Use the query type code to determine whether the query is run against
2197 : * the PK or FK table; we'll do the check as that table's owner
2198 : */
2199 3666 : if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
2200 2946 : query_rel = pk_rel;
2201 : else
2202 720 : query_rel = fk_rel;
2203 :
2204 : /*
2205 : * The values for the query are taken from the table on which the trigger
2206 : * is called - it is normally the other one with respect to query_rel. An
2207 : * exception is ri_Check_Pk_Match(), which uses the PK table for both (and
2208 : * sets queryno to RI_PLAN_CHECK_LOOKUPPK_FROM_PK). We might eventually
2209 : * need some less klugy way to determine this.
2210 : */
2211 3666 : if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK)
2212 : {
2213 2514 : source_rel = fk_rel;
2214 2514 : source_is_pk = false;
2215 : }
2216 : else
2217 : {
2218 1152 : source_rel = pk_rel;
2219 1152 : source_is_pk = true;
2220 : }
2221 :
2222 : /* Extract the parameters to be passed into the query */
2223 3666 : if (newslot)
2224 : {
2225 2570 : ri_ExtractValues(source_rel, newslot, riinfo, source_is_pk,
2226 : vals, nulls);
2227 2570 : if (oldslot)
2228 112 : ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
2229 112 : vals + riinfo->nkeys, nulls + riinfo->nkeys);
2230 : }
2231 : else
2232 : {
2233 1096 : ri_ExtractValues(source_rel, oldslot, riinfo, source_is_pk,
2234 : vals, nulls);
2235 : }
2236 :
2237 : /*
2238 : * In READ COMMITTED mode, we just need to use an up-to-date regular
2239 : * snapshot, and we will see all rows that could be interesting. But in
2240 : * transaction-snapshot mode, we can't change the transaction snapshot. If
2241 : * the caller passes detectNewRows == false then it's okay to do the query
2242 : * with the transaction snapshot; otherwise we use a current snapshot, and
2243 : * tell the executor to error out if it finds any rows under the current
2244 : * snapshot that wouldn't be visible per the transaction snapshot. Note
2245 : * that SPI_execute_snapshot will register the snapshots, so we don't need
2246 : * to bother here.
2247 : */
2248 3666 : if (IsolationUsesXactSnapshot() && detectNewRows)
2249 : {
2250 0 : CommandCounterIncrement(); /* be sure all my own work is visible */
2251 0 : test_snapshot = GetLatestSnapshot();
2252 0 : crosscheck_snapshot = GetTransactionSnapshot();
2253 : }
2254 : else
2255 : {
2256 : /* the default SPI behavior is okay */
2257 3666 : test_snapshot = InvalidSnapshot;
2258 3666 : crosscheck_snapshot = InvalidSnapshot;
2259 : }
2260 :
2261 : /*
2262 : * If this is a select query (e.g., for a 'no action' or 'restrict'
2263 : * trigger), we only need to see if there is a single row in the table,
2264 : * matching the key. Otherwise, limit = 0 - because we want the query to
2265 : * affect ALL the matching rows.
2266 : */
2267 3666 : limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
2268 :
2269 : /* Switch to proper UID to perform check as */
2270 3666 : GetUserIdAndSecContext(&save_userid, &save_sec_context);
2271 3666 : SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
2272 : save_sec_context | SECURITY_LOCAL_USERID_CHANGE |
2273 : SECURITY_NOFORCE_RLS);
2274 :
2275 : /* Finally we can run the query. */
2276 3666 : spi_result = SPI_execute_snapshot(qplan,
2277 : vals, nulls,
2278 : test_snapshot, crosscheck_snapshot,
2279 : false, false, limit);
2280 :
2281 : /* Restore UID and security context */
2282 3656 : SetUserIdAndSecContext(save_userid, save_sec_context);
2283 :
2284 : /* Check result */
2285 3656 : if (spi_result < 0)
2286 0 : elog(ERROR, "SPI_execute_snapshot returned %s", SPI_result_code_string(spi_result));
2287 :
2288 3656 : if (expect_OK >= 0 && spi_result != expect_OK)
2289 0 : ereport(ERROR,
2290 : (errcode(ERRCODE_INTERNAL_ERROR),
2291 : errmsg("referential integrity query on \"%s\" from constraint \"%s\" on \"%s\" gave unexpected result",
2292 : RelationGetRelationName(pk_rel),
2293 : NameStr(riinfo->conname),
2294 : RelationGetRelationName(fk_rel)),
2295 : errhint("This is most likely due to a rule having rewritten the query.")));
2296 :
2297 : /* XXX wouldn't it be clearer to do this part at the caller? */
2298 3656 : if (qkey->constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK &&
2299 2948 : expect_OK == SPI_OK_SELECT &&
2300 2948 : (SPI_processed == 0) == (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK))
2301 464 : ri_ReportViolation(riinfo,
2302 : pk_rel, fk_rel,
2303 : newslot ? newslot : oldslot,
2304 : NULL,
2305 : qkey->constr_queryno, false);
2306 :
2307 3192 : return SPI_processed != 0;
2308 : }
2309 :
2310 : /*
2311 : * Extract fields from a tuple into Datum/nulls arrays
2312 : */
2313 : static void
2314 3722 : ri_ExtractValues(Relation rel, TupleTableSlot *slot,
2315 : const RI_ConstraintInfo *riinfo, bool rel_is_pk,
2316 : Datum *vals, char *nulls)
2317 : {
2318 : const int16 *attnums;
2319 : bool isnull;
2320 :
2321 3722 : if (rel_is_pk)
2322 1208 : attnums = riinfo->pk_attnums;
2323 : else
2324 2514 : attnums = riinfo->fk_attnums;
2325 :
2326 8404 : for (int i = 0; i < riinfo->nkeys; i++)
2327 : {
2328 4682 : vals[i] = slot_getattr(slot, attnums[i], &isnull);
2329 4682 : nulls[i] = isnull ? 'n' : ' ';
2330 : }
2331 3722 : }
2332 :
2333 : /*
2334 : * Produce an error report
2335 : *
2336 : * If the failed constraint was on insert/update to the FK table,
2337 : * we want the key names and values extracted from there, and the error
2338 : * message to look like 'key blah is not present in PK'.
2339 : * Otherwise, the attr names and values come from the PK table and the
2340 : * message looks like 'key blah is still referenced from FK'.
2341 : */
2342 : static void
2343 518 : ri_ReportViolation(const RI_ConstraintInfo *riinfo,
2344 : Relation pk_rel, Relation fk_rel,
2345 : TupleTableSlot *violatorslot, TupleDesc tupdesc,
2346 : int queryno, bool partgone)
2347 : {
2348 : StringInfoData key_names;
2349 : StringInfoData key_values;
2350 : bool onfk;
2351 : const int16 *attnums;
2352 : Oid rel_oid;
2353 : AclResult aclresult;
2354 518 : bool has_perm = true;
2355 :
2356 : /*
2357 : * Determine which relation to complain about. If tupdesc wasn't passed
2358 : * by caller, assume the violator tuple came from there.
2359 : */
2360 518 : onfk = (queryno == RI_PLAN_CHECK_LOOKUPPK);
2361 518 : if (onfk)
2362 : {
2363 296 : attnums = riinfo->fk_attnums;
2364 296 : rel_oid = fk_rel->rd_id;
2365 296 : if (tupdesc == NULL)
2366 262 : tupdesc = fk_rel->rd_att;
2367 : }
2368 : else
2369 : {
2370 222 : attnums = riinfo->pk_attnums;
2371 222 : rel_oid = pk_rel->rd_id;
2372 222 : if (tupdesc == NULL)
2373 202 : tupdesc = pk_rel->rd_att;
2374 : }
2375 :
2376 : /*
2377 : * Check permissions- if the user does not have access to view the data in
2378 : * any of the key columns then we don't include the errdetail() below.
2379 : *
2380 : * Check if RLS is enabled on the relation first. If so, we don't return
2381 : * any specifics to avoid leaking data.
2382 : *
2383 : * Check table-level permissions next and, failing that, column-level
2384 : * privileges.
2385 : *
2386 : * When a partition at the referenced side is being detached/dropped, we
2387 : * needn't check, since the user must be the table owner anyway.
2388 : */
2389 518 : if (partgone)
2390 20 : has_perm = true;
2391 498 : else if (check_enable_rls(rel_oid, InvalidOid, true) != RLS_ENABLED)
2392 : {
2393 494 : aclresult = pg_class_aclcheck(rel_oid, GetUserId(), ACL_SELECT);
2394 494 : if (aclresult != ACLCHECK_OK)
2395 : {
2396 : /* Try for column-level permissions */
2397 0 : for (int idx = 0; idx < riinfo->nkeys; idx++)
2398 : {
2399 0 : aclresult = pg_attribute_aclcheck(rel_oid, attnums[idx],
2400 : GetUserId(),
2401 : ACL_SELECT);
2402 :
2403 : /* No access to the key */
2404 0 : if (aclresult != ACLCHECK_OK)
2405 : {
2406 0 : has_perm = false;
2407 0 : break;
2408 : }
2409 : }
2410 : }
2411 : }
2412 : else
2413 4 : has_perm = false;
2414 :
2415 518 : if (has_perm)
2416 : {
2417 : /* Get printable versions of the keys involved */
2418 514 : initStringInfo(&key_names);
2419 514 : initStringInfo(&key_values);
2420 1224 : for (int idx = 0; idx < riinfo->nkeys; idx++)
2421 : {
2422 710 : int fnum = attnums[idx];
2423 710 : Form_pg_attribute att = TupleDescAttr(tupdesc, fnum - 1);
2424 : char *name,
2425 : *val;
2426 : Datum datum;
2427 : bool isnull;
2428 :
2429 710 : name = NameStr(att->attname);
2430 :
2431 710 : datum = slot_getattr(violatorslot, fnum, &isnull);
2432 710 : if (!isnull)
2433 : {
2434 : Oid foutoid;
2435 : bool typisvarlena;
2436 :
2437 710 : getTypeOutputInfo(att->atttypid, &foutoid, &typisvarlena);
2438 710 : val = OidOutputFunctionCall(foutoid, datum);
2439 : }
2440 : else
2441 0 : val = "null";
2442 :
2443 710 : if (idx > 0)
2444 : {
2445 196 : appendStringInfoString(&key_names, ", ");
2446 196 : appendStringInfoString(&key_values, ", ");
2447 : }
2448 710 : appendStringInfoString(&key_names, name);
2449 710 : appendStringInfoString(&key_values, val);
2450 : }
2451 : }
2452 :
2453 518 : if (partgone)
2454 20 : ereport(ERROR,
2455 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
2456 : errmsg("removing partition \"%s\" violates foreign key constraint \"%s\"",
2457 : RelationGetRelationName(pk_rel),
2458 : NameStr(riinfo->conname)),
2459 : errdetail("Key (%s)=(%s) still referenced from table \"%s\".",
2460 : key_names.data, key_values.data,
2461 : RelationGetRelationName(fk_rel))));
2462 498 : else if (onfk)
2463 296 : ereport(ERROR,
2464 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
2465 : errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
2466 : RelationGetRelationName(fk_rel),
2467 : NameStr(riinfo->conname)),
2468 : has_perm ?
2469 : errdetail("Key (%s)=(%s) is not present in table \"%s\".",
2470 : key_names.data, key_values.data,
2471 : RelationGetRelationName(pk_rel)) :
2472 : errdetail("Key is not present in table \"%s\".",
2473 : RelationGetRelationName(pk_rel)),
2474 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
2475 : else
2476 202 : ereport(ERROR,
2477 : (errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
2478 : errmsg("update or delete on table \"%s\" violates foreign key constraint \"%s\" on table \"%s\"",
2479 : RelationGetRelationName(pk_rel),
2480 : NameStr(riinfo->conname),
2481 : RelationGetRelationName(fk_rel)),
2482 : has_perm ?
2483 : errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
2484 : key_names.data, key_values.data,
2485 : RelationGetRelationName(fk_rel)) :
2486 : errdetail("Key is still referenced from table \"%s\".",
2487 : RelationGetRelationName(fk_rel)),
2488 : errtableconstraint(fk_rel, NameStr(riinfo->conname))));
2489 : }
2490 :
2491 :
2492 : /*
2493 : * ri_NullCheck -
2494 : *
2495 : * Determine the NULL state of all key values in a tuple
2496 : *
2497 : * Returns one of RI_KEYS_ALL_NULL, RI_KEYS_NONE_NULL or RI_KEYS_SOME_NULL.
2498 : */
2499 : static int
2500 4564 : ri_NullCheck(TupleDesc tupDesc,
2501 : TupleTableSlot *slot,
2502 : const RI_ConstraintInfo *riinfo, bool rel_is_pk)
2503 : {
2504 : const int16 *attnums;
2505 4564 : bool allnull = true;
2506 4564 : bool nonenull = true;
2507 :
2508 4564 : if (rel_is_pk)
2509 1172 : attnums = riinfo->pk_attnums;
2510 : else
2511 3392 : attnums = riinfo->fk_attnums;
2512 :
2513 10136 : for (int i = 0; i < riinfo->nkeys; i++)
2514 : {
2515 5572 : if (slot_attisnull(slot, attnums[i]))
2516 336 : nonenull = false;
2517 : else
2518 5236 : allnull = false;
2519 : }
2520 :
2521 4564 : if (allnull)
2522 176 : return RI_KEYS_ALL_NULL;
2523 :
2524 4388 : if (nonenull)
2525 4276 : return RI_KEYS_NONE_NULL;
2526 :
2527 112 : return RI_KEYS_SOME_NULL;
2528 : }
2529 :
2530 :
2531 : /*
2532 : * ri_InitHashTables -
2533 : *
2534 : * Initialize our internal hash tables.
2535 : */
2536 : static void
2537 344 : ri_InitHashTables(void)
2538 : {
2539 : HASHCTL ctl;
2540 :
2541 344 : memset(&ctl, 0, sizeof(ctl));
2542 344 : ctl.keysize = sizeof(Oid);
2543 344 : ctl.entrysize = sizeof(RI_ConstraintInfo);
2544 344 : ri_constraint_cache = hash_create("RI constraint cache",
2545 : RI_INIT_CONSTRAINTHASHSIZE,
2546 : &ctl, HASH_ELEM | HASH_BLOBS);
2547 :
2548 : /* Arrange to flush cache on pg_constraint changes */
2549 344 : CacheRegisterSyscacheCallback(CONSTROID,
2550 : InvalidateConstraintCacheCallBack,
2551 : (Datum) 0);
2552 :
2553 344 : memset(&ctl, 0, sizeof(ctl));
2554 344 : ctl.keysize = sizeof(RI_QueryKey);
2555 344 : ctl.entrysize = sizeof(RI_QueryHashEntry);
2556 344 : ri_query_cache = hash_create("RI query cache",
2557 : RI_INIT_QUERYHASHSIZE,
2558 : &ctl, HASH_ELEM | HASH_BLOBS);
2559 :
2560 344 : memset(&ctl, 0, sizeof(ctl));
2561 344 : ctl.keysize = sizeof(RI_CompareKey);
2562 344 : ctl.entrysize = sizeof(RI_CompareHashEntry);
2563 344 : ri_compare_cache = hash_create("RI compare cache",
2564 : RI_INIT_QUERYHASHSIZE,
2565 : &ctl, HASH_ELEM | HASH_BLOBS);
2566 344 : }
2567 :
2568 :
2569 : /*
2570 : * ri_FetchPreparedPlan -
2571 : *
2572 : * Lookup for a query key in our private hash table of prepared
2573 : * and saved SPI execution plans. Return the plan if found or NULL.
2574 : */
2575 : static SPIPlanPtr
2576 3666 : ri_FetchPreparedPlan(RI_QueryKey *key)
2577 : {
2578 : RI_QueryHashEntry *entry;
2579 : SPIPlanPtr plan;
2580 :
2581 : /*
2582 : * On the first call initialize the hashtable
2583 : */
2584 3666 : if (!ri_query_cache)
2585 0 : ri_InitHashTables();
2586 :
2587 : /*
2588 : * Lookup for the key
2589 : */
2590 3666 : entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
2591 : (void *) key,
2592 : HASH_FIND, NULL);
2593 3666 : if (entry == NULL)
2594 1990 : return NULL;
2595 :
2596 : /*
2597 : * Check whether the plan is still valid. If it isn't, we don't want to
2598 : * simply rely on plancache.c to regenerate it; rather we should start
2599 : * from scratch and rebuild the query text too. This is to cover cases
2600 : * such as table/column renames. We depend on the plancache machinery to
2601 : * detect possible invalidations, though.
2602 : *
2603 : * CAUTION: this check is only trustworthy if the caller has already
2604 : * locked both FK and PK rels.
2605 : */
2606 1676 : plan = entry->plan;
2607 1676 : if (plan && SPI_plan_is_valid(plan))
2608 1514 : return plan;
2609 :
2610 : /*
2611 : * Otherwise we might as well flush the cached plan now, to free a little
2612 : * memory space before we make a new one.
2613 : */
2614 162 : entry->plan = NULL;
2615 162 : if (plan)
2616 162 : SPI_freeplan(plan);
2617 :
2618 162 : return NULL;
2619 : }
2620 :
2621 :
2622 : /*
2623 : * ri_HashPreparedPlan -
2624 : *
2625 : * Add another plan to our private SPI query plan hashtable.
2626 : */
2627 : static void
2628 2152 : ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan)
2629 : {
2630 : RI_QueryHashEntry *entry;
2631 : bool found;
2632 :
2633 : /*
2634 : * On the first call initialize the hashtable
2635 : */
2636 2152 : if (!ri_query_cache)
2637 0 : ri_InitHashTables();
2638 :
2639 : /*
2640 : * Add the new plan. We might be overwriting an entry previously found
2641 : * invalid by ri_FetchPreparedPlan.
2642 : */
2643 2152 : entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
2644 : (void *) key,
2645 : HASH_ENTER, &found);
2646 : Assert(!found || entry->plan == NULL);
2647 2152 : entry->plan = plan;
2648 2152 : }
2649 :
2650 :
2651 : /*
2652 : * ri_KeysEqual -
2653 : *
2654 : * Check if all key values in OLD and NEW are equal.
2655 : *
2656 : * Note: at some point we might wish to redefine this as checking for
2657 : * "IS NOT DISTINCT" rather than "=", that is, allow two nulls to be
2658 : * considered equal. Currently there is no need since all callers have
2659 : * previously found at least one of the rows to contain no nulls.
2660 : */
2661 : static bool
2662 1240 : ri_KeysEqual(Relation rel, TupleTableSlot *oldslot, TupleTableSlot *newslot,
2663 : const RI_ConstraintInfo *riinfo, bool rel_is_pk)
2664 : {
2665 : const int16 *attnums;
2666 :
2667 1240 : if (rel_is_pk)
2668 748 : attnums = riinfo->pk_attnums;
2669 : else
2670 492 : attnums = riinfo->fk_attnums;
2671 :
2672 : /* XXX: could be worthwhile to fetch all necessary attrs at once */
2673 4320 : for (int i = 0; i < riinfo->nkeys; i++)
2674 : {
2675 : Datum oldvalue;
2676 : Datum newvalue;
2677 : bool isnull;
2678 :
2679 : /*
2680 : * Get one attribute's oldvalue. If it is NULL - they're not equal.
2681 : */
2682 1316 : oldvalue = slot_getattr(oldslot, attnums[i], &isnull);
2683 1316 : if (isnull)
2684 420 : return false;
2685 :
2686 : /*
2687 : * Get one attribute's newvalue. If it is NULL - they're not equal.
2688 : */
2689 1292 : newvalue = slot_getattr(newslot, attnums[i], &isnull);
2690 1292 : if (isnull)
2691 0 : return false;
2692 :
2693 1292 : if (rel_is_pk)
2694 : {
2695 : /*
2696 : * If we are looking at the PK table, then do a bytewise
2697 : * comparison. We must propagate PK changes if the value is
2698 : * changed to one that "looks" different but would compare as
2699 : * equal using the equality operator. This only makes a
2700 : * difference for ON UPDATE CASCADE, but for consistency we treat
2701 : * all changes to the PK the same.
2702 : */
2703 804 : Form_pg_attribute att = TupleDescAttr(oldslot->tts_tupleDescriptor, attnums[i] - 1);
2704 :
2705 804 : if (!datum_image_eq(oldvalue, newvalue, att->attbyval, att->attlen))
2706 276 : return false;
2707 : }
2708 : else
2709 : {
2710 : /*
2711 : * For the FK table, compare with the appropriate equality
2712 : * operator. Changes that compare equal will still satisfy the
2713 : * constraint after the update.
2714 : */
2715 488 : if (!ri_AttributesEqual(riinfo->ff_eq_oprs[i], RIAttType(rel, attnums[i]),
2716 : oldvalue, newvalue))
2717 96 : return false;
2718 : }
2719 : }
2720 :
2721 844 : return true;
2722 : }
2723 :
2724 :
2725 : /*
2726 : * ri_AttributesEqual -
2727 : *
2728 : * Call the appropriate equality comparison operator for two values.
2729 : *
2730 : * NB: we have already checked that neither value is null.
2731 : */
2732 : static bool
2733 488 : ri_AttributesEqual(Oid eq_opr, Oid typeid,
2734 : Datum oldvalue, Datum newvalue)
2735 : {
2736 488 : RI_CompareHashEntry *entry = ri_HashCompareOp(eq_opr, typeid);
2737 :
2738 : /* Do we need to cast the values? */
2739 488 : if (OidIsValid(entry->cast_func_finfo.fn_oid))
2740 : {
2741 8 : oldvalue = FunctionCall3(&entry->cast_func_finfo,
2742 : oldvalue,
2743 : Int32GetDatum(-1), /* typmod */
2744 : BoolGetDatum(false)); /* implicit coercion */
2745 8 : newvalue = FunctionCall3(&entry->cast_func_finfo,
2746 : newvalue,
2747 : Int32GetDatum(-1), /* typmod */
2748 : BoolGetDatum(false)); /* implicit coercion */
2749 : }
2750 :
2751 : /*
2752 : * Apply the comparison operator.
2753 : *
2754 : * Note: This function is part of a call stack that determines whether an
2755 : * update to a row is significant enough that it needs checking or action
2756 : * on the other side of a foreign-key constraint. Therefore, the
2757 : * comparison here would need to be done with the collation of the *other*
2758 : * table. For simplicity (e.g., we might not even have the other table
2759 : * open), we'll just use the default collation here, which could lead to
2760 : * some false negatives. All this would break if we ever allow
2761 : * database-wide collations to be nondeterministic.
2762 : */
2763 488 : return DatumGetBool(FunctionCall2Coll(&entry->eq_opr_finfo,
2764 : DEFAULT_COLLATION_OID,
2765 : oldvalue, newvalue));
2766 : }
2767 :
2768 : /*
2769 : * ri_HashCompareOp -
2770 : *
2771 : * See if we know how to compare two values, and create a new hash entry
2772 : * if not.
2773 : */
2774 : static RI_CompareHashEntry *
2775 488 : ri_HashCompareOp(Oid eq_opr, Oid typeid)
2776 : {
2777 : RI_CompareKey key;
2778 : RI_CompareHashEntry *entry;
2779 : bool found;
2780 :
2781 : /*
2782 : * On the first call initialize the hashtable
2783 : */
2784 488 : if (!ri_compare_cache)
2785 0 : ri_InitHashTables();
2786 :
2787 : /*
2788 : * Find or create a hash entry. Note we're assuming RI_CompareKey
2789 : * contains no struct padding.
2790 : */
2791 488 : key.eq_opr = eq_opr;
2792 488 : key.typeid = typeid;
2793 488 : entry = (RI_CompareHashEntry *) hash_search(ri_compare_cache,
2794 : (void *) &key,
2795 : HASH_ENTER, &found);
2796 488 : if (!found)
2797 248 : entry->valid = false;
2798 :
2799 : /*
2800 : * If not already initialized, do so. Since we'll keep this hash entry
2801 : * for the life of the backend, put any subsidiary info for the function
2802 : * cache structs into TopMemoryContext.
2803 : */
2804 488 : if (!entry->valid)
2805 : {
2806 : Oid lefttype,
2807 : righttype,
2808 : castfunc;
2809 : CoercionPathType pathtype;
2810 :
2811 : /* We always need to know how to call the equality operator */
2812 248 : fmgr_info_cxt(get_opcode(eq_opr), &entry->eq_opr_finfo,
2813 : TopMemoryContext);
2814 :
2815 : /*
2816 : * If we chose to use a cast from FK to PK type, we may have to apply
2817 : * the cast function to get to the operator's input type.
2818 : *
2819 : * XXX eventually it would be good to support array-coercion cases
2820 : * here and in ri_AttributesEqual(). At the moment there is no point
2821 : * because cases involving nonidentical array types will be rejected
2822 : * at constraint creation time.
2823 : *
2824 : * XXX perhaps also consider supporting CoerceViaIO? No need at the
2825 : * moment since that will never be generated for implicit coercions.
2826 : */
2827 248 : op_input_types(eq_opr, &lefttype, &righttype);
2828 : Assert(lefttype == righttype);
2829 248 : if (typeid == lefttype)
2830 244 : castfunc = InvalidOid; /* simplest case */
2831 : else
2832 : {
2833 4 : pathtype = find_coercion_pathway(lefttype, typeid,
2834 : COERCION_IMPLICIT,
2835 : &castfunc);
2836 4 : if (pathtype != COERCION_PATH_FUNC &&
2837 : pathtype != COERCION_PATH_RELABELTYPE)
2838 : {
2839 : /*
2840 : * The declared input type of the eq_opr might be a
2841 : * polymorphic type such as ANYARRAY or ANYENUM, or other
2842 : * special cases such as RECORD; find_coercion_pathway
2843 : * currently doesn't subsume these special cases.
2844 : */
2845 0 : if (!IsBinaryCoercible(typeid, lefttype))
2846 0 : elog(ERROR, "no conversion function from %s to %s",
2847 : format_type_be(typeid),
2848 : format_type_be(lefttype));
2849 : }
2850 : }
2851 248 : if (OidIsValid(castfunc))
2852 4 : fmgr_info_cxt(castfunc, &entry->cast_func_finfo,
2853 : TopMemoryContext);
2854 : else
2855 244 : entry->cast_func_finfo.fn_oid = InvalidOid;
2856 248 : entry->valid = true;
2857 : }
2858 :
2859 488 : return entry;
2860 : }
2861 :
2862 :
2863 : /*
2864 : * Given a trigger function OID, determine whether it is an RI trigger,
2865 : * and if so whether it is attached to PK or FK relation.
2866 : */
2867 : int
2868 3388 : RI_FKey_trigger_type(Oid tgfoid)
2869 : {
2870 3388 : switch (tgfoid)
2871 : {
2872 : case F_RI_FKEY_CASCADE_DEL:
2873 : case F_RI_FKEY_CASCADE_UPD:
2874 : case F_RI_FKEY_RESTRICT_DEL:
2875 : case F_RI_FKEY_RESTRICT_UPD:
2876 : case F_RI_FKEY_SETNULL_DEL:
2877 : case F_RI_FKEY_SETNULL_UPD:
2878 : case F_RI_FKEY_SETDEFAULT_DEL:
2879 : case F_RI_FKEY_SETDEFAULT_UPD:
2880 : case F_RI_FKEY_NOACTION_DEL:
2881 : case F_RI_FKEY_NOACTION_UPD:
2882 1172 : return RI_TRIGGER_PK;
2883 :
2884 : case F_RI_FKEY_CHECK_INS:
2885 : case F_RI_FKEY_CHECK_UPD:
2886 678 : return RI_TRIGGER_FK;
2887 : }
2888 :
2889 1538 : return RI_TRIGGER_NONE;
2890 : }
|
