From 201737168c4ed5b14313d111d8d746c7f072f24e Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 19 Apr 2002 16:36:08 +0000 Subject: [PATCH] pg_trigger's index on tgrelid is replaced by a unique index on (tgrelid, tgname). This provides an additional check on trigger name uniqueness per-table (which was already enforced by the code anyway). With this change, RelationBuildTriggers will read the triggers in order by tgname, since it's scanning using this index. Since a predictable trigger ordering has been requested for some time, document this behavior as a feature. Also document that rules fire in name order, since yesterday's changes to pg_rewrite indexing cause that too. --- doc/src/sgml/ref/create_rule.sgml | 40 +++++--- doc/src/sgml/ref/create_trigger.sgml | 48 +++++++--- doc/src/sgml/trigger.sgml | 107 ++++++++++++---------- src/backend/catalog/indexing.c | 4 +- src/backend/commands/comment.c | 23 +++-- src/backend/commands/tablecmds.c | 6 +- src/backend/commands/trigger.c | 86 +++++++++-------- src/backend/utils/cache/relcache.c | 74 +++++++-------- src/include/catalog/catversion.h | 4 +- src/include/catalog/indexing.h | 8 +- src/test/regress/expected/foreign_key.out | 2 +- 11 files changed, 230 insertions(+), 172 deletions(-) diff --git a/doc/src/sgml/ref/create_rule.sgml b/doc/src/sgml/ref/create_rule.sgml index c9cc209843..1c5786a0c9 100644 --- a/doc/src/sgml/ref/create_rule.sgml +++ b/doc/src/sgml/ref/create_rule.sgml @@ -1,5 +1,5 @@ @@ -22,7 +22,7 @@ PostgreSQL documentation CREATE RULE name AS ON event - TO object [ WHERE condition ] + TO table [ WHERE condition ] DO [ INSTEAD ] action where action can be: @@ -48,7 +48,8 @@ NOTHING name - The name of a rule to create. + The name of a rule to create. This must be distinct from the name + of any other rule for the same table. @@ -63,14 +64,11 @@ NOTHING - object + table - Object is either table - or table.column. (Currently, only the - table form is - actually implemented.) + The name (optionally schema-qualified) of the table or view the rule + applies to. @@ -103,8 +101,7 @@ NOTHING Within the condition and action, the special table names new and old may be - used to refer to values in the referenced table (the - object). + used to refer to values in the referenced table. new is valid in ON INSERT and ON UPDATE rules to refer to the new row being inserted or updated. old is valid in ON UPDATE and ON DELETE @@ -159,7 +156,7 @@ CREATE accessed, inserted, updated, or deleted, there is an old instance (for selects, updates and deletes) and a new instance (for inserts and updates). All the rules for the given event type and the given target - object (table) are examined, in an unspecified order. If the + table are examined successively (in order by name). If the condition specified in the WHERE clause (if any) is true, the action part of the rule is @@ -178,8 +175,7 @@ CREATE The action part of the rule can consist of one or more queries. To write multiple queries, surround them with parentheses. Such queries will be performed in the - specified order (whereas there are no guarantees about the execution - order of multiple rules for an object). The action can also be NOTHING indicating no action. Thus, a DO INSTEAD NOTHING rule suppresses the original query from executing (when its condition is true); a DO NOTHING rule @@ -191,6 +187,20 @@ CREATE executes with the same command and transaction identifier as the user command that caused activation. + + + It is important to realize that a rule is really a query transformation + mechanism, or query macro. The entire query is processed to convert it + into a series of queries that include the rule actions. This occurs + before evaluation of the query starts. So, conditional rules are + handled by adding the rule condition to the WHERE clause of the action(s) + derived from the rule. The above description of a rule as an operation + that executes for each row is thus somewhat misleading. If you actually + want an operation that fires independently for each physical row, you + probably want to use a trigger not a rule. Rules are most useful for + situations that call for transforming entire queries independently of + the specific data being handled. + @@ -202,7 +212,7 @@ CREATE Presently, ON SELECT rules must be unconditional INSTEAD rules and must have actions that consist of a single SELECT query. Thus, an ON SELECT - rule effectively turns the object table into a view, whose visible + rule effectively turns the table into a view, whose visible contents are the rows returned by the rule's SELECT query rather than whatever had been stored in the table (if anything). It is considered better style to write a CREATE VIEW command than to create a real table diff --git a/doc/src/sgml/ref/create_trigger.sgml b/doc/src/sgml/ref/create_trigger.sgml index f3e8276638..1d24be9a2b 100644 --- a/doc/src/sgml/ref/create_trigger.sgml +++ b/doc/src/sgml/ref/create_trigger.sgml @@ -1,5 +1,5 @@ @@ -44,15 +44,8 @@ CREATE TRIGGER name { BEFORE | AFTE name - The name to give the new trigger. - - - - - table - - - The name of an existing table. + The name to give the new trigger. This must be distinct from the name + of any other trigger for the same table. @@ -64,11 +57,32 @@ CREATE TRIGGER name { BEFORE | AFTE + + table + + + The name (optionally schema-qualified) of the table the trigger is for. + + + func - A user-supplied function. + A user-supplied function that is declared as taking no arguments + and returning type opaque. + + + + + arguments + + + An optional comma-separated list of arguments to be provided to the + function when the trigger is executed, along with the standard trigger + data such as old and new tuple contents. The arguments are literal + string constants. Simple names and numeric constants may be written + here too, but they will all be converted to strings. @@ -130,6 +144,12 @@ CREATE after the event, all changes, including the last insertion, update, or deletion, are visible to the trigger. + + + If multiple triggers of the same kind are defined for the same event, + they will be fired in alphabetical order by name. + + SELECT does not modify any rows so you can not create SELECT triggers. Rules and views are more @@ -262,6 +282,12 @@ CREATE TABLE distributors ( + + + SQL99 specifies that multiple triggers should be fired in + time-of-creation order. PostgreSQL + uses name order, which was judged more convenient to work with. + diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml index 8dd9815e0c..5456f4d0cd 100644 --- a/doc/src/sgml/trigger.sgml +++ b/doc/src/sgml/trigger.sgml @@ -1,5 +1,5 @@ @@ -14,8 +14,8 @@ $Header: /cvsroot/pgsql/doc/src/sgml/trigger.sgml,v 1.22 2002/04/01 22:36:06 tgl AFTER on INSERT, DELETE or UPDATE of a tuple as a trigger event. - - Trigger Creation + + Trigger Definition If a trigger event occurs, the trigger manager (called by the Executor) @@ -24,13 +24,17 @@ $Header: /cvsroot/pgsql/doc/src/sgml/trigger.sgml,v 1.22 2002/04/01 22:36:06 tgl - The trigger function must be defined before the trigger is created as a - function taking no arguments and returning opaque. If the function is - written in C, it must use the version 1 function manager interface. + The trigger function must be defined before the trigger itself can be + created. The trigger function must be declared as a + function taking no arguments and returning type opaque. + (The trigger function receives its input through a TriggerData + structure, not in the form of ordinary function arguments.) + If the function is written in C, it must use the version 1 + function manager interface. - The syntax for creating triggers is as follows: + The syntax for creating triggers is: CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | DELETE | UPDATE [ OR ... ] ] @@ -48,9 +52,9 @@ CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | - The name of the trigger is - used if you ever have to delete the trigger. - It is used as an argument to the DROP TRIGGER command. + The trigger must have a name distinct from all other triggers on + the same table. The name is needed + if you ever have to delete the trigger. @@ -72,7 +76,7 @@ CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | UPDATE - The next element of the command determines on what event(s) will trigger + The next element of the command determines what event(s) will trigger the function. Multiple events can be specified separated by OR. @@ -82,7 +86,7 @@ CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | relation - The relation name determines which table the event applies to. + The relation name indicates which table the event applies to. @@ -94,6 +98,7 @@ CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | The FOR EACH clause determines whether the trigger is fired for each affected row or before (or after) the entire statement has completed. + Currently only the ROW case is supported. @@ -102,7 +107,7 @@ CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | procedure - The procedure name is the function called. + The procedure name is the function to be called. @@ -112,23 +117,23 @@ CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | The arguments passed to the function in the TriggerData structure. - The purpose of passing arguments to the function is to allow different + This is either empty or a list of one or more simple literal + constants (which will be passed to the function as strings). + + + + The purpose of including arguments in the trigger definition + is to allow different triggers with similar requirements to call the same function. - - - - Also, procedure - may be used for triggering different relations (these - functions are named as general trigger functions). - - - - As example of using both features above, there could be a general - function that takes as its arguments two field names and puts the current - user in one and the current timestamp in the other. This allows triggers to - be written on INSERT events to automatically track creation of records in a - transaction table for example. It could also be used as a last updated - function if used in an UPDATE event. + As an example, there could be a generalized trigger + function that takes as its arguments two field names and puts the + current user in one and the current timestamp in the other. + Properly written, this trigger function would be independent of + the specific table it is triggering on. So the same function + could be used for INSERT events on any table with suitable fields, + to automatically track creation of records in a transaction table for + example. It could also be used to track last-update events if + defined as an UPDATE trigger. @@ -136,8 +141,8 @@ CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | - Trigger functions return HeapTuple to the calling Executor. This - is ignored for triggers fired after an INSERT, DELETE or UPDATE operation + Trigger functions return a HeapTuple to the calling Executor. The return + value is ignored for triggers fired AFTER an operation, but it allows BEFORE triggers to: @@ -150,33 +155,41 @@ CREATE TRIGGER trigger [ BEFORE | AFTER ] [ INSERT | - Return a pointer to another tuple (INSERT and UPDATE only) which will - be inserted (as the new version of the updated tuple if UPDATE) instead - of original tuple. + For INSERT and UPDATE triggers only, the returned tuple becomes the + tuple which will be inserted or will replace the tuple being updated. + This allows the trigger function to modify the row being inserted or + updated. + + A BEFORE trigger that does not intend to cause either of these behaviors + must be careful to return the same NEW tuple it is passed. Note that there is no initialization performed by the CREATE TRIGGER - handler. This will be changed in the future. Also, if more than one trigger - is defined for the same event on the same relation, the order of trigger - firing is unpredictable. This may be changed in the future. + handler. This may be changed in the future. + + + + If more than one trigger + is defined for the same event on the same relation, the triggers will + be fired in alphabetical order by name. In the case of BEFORE triggers, + the possibly-modified tuple returned by each trigger becomes the input + to the next trigger. If any BEFORE trigger returns NULL, the operation + is abandoned and subsequent triggers are not fired. If a trigger function executes SQL-queries (using SPI) then these queries may fire triggers again. This is known as cascading triggers. There is no - explicit limitation on the number of cascade levels. - - - - If a trigger is fired by INSERT and inserts a new tuple in the same - relation then this trigger will be fired again. Currently, there is nothing - provided for synchronization (etc) of these cases but this may change. At - the moment, there is function funny_dup17() in the regress tests which uses - some techniques to stop recursion (cascading) on itself... + direct limitation on the number of cascade levels. It is possible for + cascades to cause recursive invocation of the same trigger --- for + example, an INSERT trigger might execute a query that inserts an + additional tuple into the same table, causing the INSERT trigger to be + fired again. It is the trigger programmer's + responsibility to avoid infinite recursion in such scenarios. @@ -326,7 +339,7 @@ typedef struct TriggerData is a pointer to structure describing the triggered relation. Look at src/include/utils/rel.h for details about this structure. The most - interest things are tg_relation->rd_att (descriptor of the relation + interesting things are tg_relation->rd_att (descriptor of the relation tuples) and tg_relation->rd_rel->relname (relation's name. This is not char*, but NameData. Use SPI_getrelname(tg_relation) to get char* if you need a copy of name). diff --git a/src/backend/catalog/indexing.c b/src/backend/catalog/indexing.c index 6ccb1ef0b2..cc26af128a 100644 --- a/src/backend/catalog/indexing.c +++ b/src/backend/catalog/indexing.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/catalog/indexing.c,v 1.91 2002/04/18 20:01:09 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/catalog/indexing.c,v 1.92 2002/04/19 16:36:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -74,7 +74,7 @@ char *Name_pg_shadow_indices[Num_pg_shadow_indices] = char *Name_pg_statistic_indices[Num_pg_statistic_indices] = {StatisticRelidAttnumIndex}; char *Name_pg_trigger_indices[Num_pg_trigger_indices] = -{TriggerRelidIndex, TriggerConstrNameIndex, TriggerConstrRelidIndex, TriggerOidIndex}; +{TriggerRelidNameIndex, TriggerConstrNameIndex, TriggerConstrRelidIndex, TriggerOidIndex}; char *Name_pg_type_indices[Num_pg_type_indices] = {TypeNameNspIndex, TypeOidIndex}; char *Name_pg_description_indices[Num_pg_description_indices] = diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c index 07b14ca4fe..63c023cf0e 100644 --- a/src/backend/commands/comment.c +++ b/src/backend/commands/comment.c @@ -7,7 +7,7 @@ * Copyright (c) 1999-2001, PostgreSQL Global Development Group * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/commands/comment.c,v 1.42 2002/04/18 20:01:09 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/commands/comment.c,v 1.43 2002/04/19 16:36:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -753,7 +753,7 @@ CommentTrigger(List *qualname, char *comment) Relation pg_trigger, relation; HeapTuple triggertuple; - HeapScanDesc scan; + SysScanDesc scan; ScanKeyData entry[2]; Oid oid; @@ -774,17 +774,22 @@ CommentTrigger(List *qualname, char *comment) elog(ERROR, "you are not permitted to comment on trigger '%s' for relation '%s'", trigname, RelationGetRelationName(relation)); - /* Fetch the trigger oid from pg_trigger */ - + /* + * Fetch the trigger tuple from pg_trigger. There can be only one + * because of the unique index. + */ pg_trigger = heap_openr(TriggerRelationName, AccessShareLock); - ScanKeyEntryInitialize(&entry[0], 0x0, Anum_pg_trigger_tgrelid, + ScanKeyEntryInitialize(&entry[0], 0x0, + Anum_pg_trigger_tgrelid, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(relation))); - ScanKeyEntryInitialize(&entry[1], 0x0, Anum_pg_trigger_tgname, + ScanKeyEntryInitialize(&entry[1], 0x0, + Anum_pg_trigger_tgname, F_NAMEEQ, CStringGetDatum(trigname)); - scan = heap_beginscan(pg_trigger, 0, SnapshotNow, 2, entry); - triggertuple = heap_getnext(scan, 0); + scan = systable_beginscan(pg_trigger, TriggerRelidNameIndex, true, + SnapshotNow, 2, entry); + triggertuple = systable_getnext(scan); /* If no trigger exists for the relation specified, notify user */ @@ -794,7 +799,7 @@ CommentTrigger(List *qualname, char *comment) oid = triggertuple->t_data->t_oid; - heap_endscan(scan); + systable_endscan(scan); /* Create the comments with the pg_trigger oid */ diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 8abd8cf80d..b0b73af76e 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.3 2002/04/18 20:01:09 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.4 2002/04/19 16:36:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -2909,10 +2909,10 @@ update_ri_trigger_args(Oid relid, if (fk_scan) irel = index_openr(TriggerConstrRelidIndex); else - irel = index_openr(TriggerRelidIndex); + irel = index_openr(TriggerRelidNameIndex); ScanKeyEntryInitialize(&skey[0], 0x0, - 1, /* always column 1 of index */ + 1, /* column 1 of index in either case */ F_OIDEQ, ObjectIdGetDatum(relid)); idxtgscan = index_beginscan(irel, false, 1, skey); diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c index 891b9f3cfb..c00b4bebac 100644 --- a/src/backend/commands/trigger.c +++ b/src/backend/commands/trigger.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.113 2002/04/12 20:38:24 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.114 2002/04/19 16:36:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -90,14 +90,15 @@ CreateTrigger(CreateTrigStmt *stmt) elog(ERROR, "permission denied"); /* - * If trigger is a constraint, user trigger name as constraint name + * If trigger is an RI constraint, use trigger name as constraint name * and build a unique trigger name instead. */ if (stmt->isconstraint) { constrname = stmt->trigname; + snprintf(constrtrigname, sizeof(constrtrigname), + "RI_ConstraintTrigger_%u", newoid()); stmt->trigname = constrtrigname; - sprintf(constrtrigname, "RI_ConstraintTrigger_%u", newoid()); if (stmt->constrrel != NULL) constrrelid = RangeVarGetRelid(stmt->constrrel, false); @@ -139,15 +140,20 @@ CreateTrigger(CreateTrigStmt *stmt) } /* - * Scan pg_trigger for existing triggers on relation. NOTE that this - * is cool only because we have AccessExclusiveLock on the relation, - * so the trigger set won't be changing underneath us. + * Scan pg_trigger for existing triggers on relation. We do this mainly + * because we must count them; a secondary benefit is to give a nice + * error message if there's already a trigger of the same name. (The + * unique index on tgrelid/tgname would complain anyway.) + * + * NOTE that this is cool only because we have AccessExclusiveLock on the + * relation, so the trigger set won't be changing underneath us. */ tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); - ScanKeyEntryInitialize(&key, 0, Anum_pg_trigger_tgrelid, + ScanKeyEntryInitialize(&key, 0, + Anum_pg_trigger_tgrelid, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); - tgscan = systable_beginscan(tgrel, TriggerRelidIndex, true, + tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, SnapshotNow, 1, &key); while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) { @@ -336,15 +342,20 @@ DropTrigger(Oid relid, const char *trigname) /* * Search pg_trigger, delete target trigger, count remaining triggers - * for relation. Note this is OK only because we have - * AccessExclusiveLock on the rel, so no one else is creating/deleting - * triggers on this rel at the same time. + * for relation. (Although we could fetch and delete the target + * trigger directly, we'd still have to scan the remaining triggers, + * so we may as well do both in one indexscan.) + * + * Note this is OK only because we have AccessExclusiveLock on the rel, + * so no one else is creating/deleting triggers on this rel at the same + * time. */ tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); - ScanKeyEntryInitialize(&key, 0, Anum_pg_trigger_tgrelid, + ScanKeyEntryInitialize(&key, 0, + Anum_pg_trigger_tgrelid, F_OIDEQ, ObjectIdGetDatum(relid)); - tgscan = systable_beginscan(tgrel, TriggerRelidIndex, true, + tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, SnapshotNow, 1, &key); while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) { @@ -409,10 +420,11 @@ RelationRemoveTriggers(Relation rel) bool found = false; tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); - ScanKeyEntryInitialize(&key, 0, Anum_pg_trigger_tgrelid, + ScanKeyEntryInitialize(&key, 0, + Anum_pg_trigger_tgrelid, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); - tgscan = systable_beginscan(tgrel, TriggerRelidIndex, true, + tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, SnapshotNow, 1, &key); while (HeapTupleIsValid(tup = systable_getnext(tgscan))) @@ -462,7 +474,8 @@ RelationRemoveTriggers(Relation rel) /* * Also drop all constraint triggers referencing this relation */ - ScanKeyEntryInitialize(&key, 0, Anum_pg_trigger_tgconstrrelid, + ScanKeyEntryInitialize(&key, 0, + Anum_pg_trigger_tgconstrrelid, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); tgscan = systable_beginscan(tgrel, TriggerConstrRelidIndex, true, @@ -502,7 +515,7 @@ RelationBuildTriggers(Relation relation) { TriggerDesc *trigdesc; int ntrigs = relation->rd_rel->reltriggers; - Trigger *triggers = NULL; + Trigger *triggers; int found = 0; Relation tgrel; ScanKeyData skey; @@ -511,6 +524,15 @@ RelationBuildTriggers(Relation relation) struct varlena *val; bool isnull; + triggers = (Trigger *) MemoryContextAlloc(CacheMemoryContext, + ntrigs * sizeof(Trigger)); + + /* + * Note: since we scan the triggers using TriggerRelidNameIndex, + * we will be reading the triggers in name order, except possibly + * during emergency-recovery operations (ie, IsIgnoringSystemIndexes). + * This in turn ensures that triggers will be fired in name order. + */ ScanKeyEntryInitialize(&skey, (bits16) 0x0, (AttrNumber) Anum_pg_trigger_tgrelid, @@ -518,7 +540,7 @@ RelationBuildTriggers(Relation relation) ObjectIdGetDatum(RelationGetRelid(relation))); tgrel = heap_openr(TriggerRelationName, AccessShareLock); - tgscan = systable_beginscan(tgrel, TriggerRelidIndex, true, + tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, SnapshotNow, 1, &skey); while (HeapTupleIsValid(htup = systable_getnext(tgscan))) @@ -526,16 +548,9 @@ RelationBuildTriggers(Relation relation) Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup); Trigger *build; - if (found == ntrigs) + if (found >= ntrigs) elog(ERROR, "RelationBuildTriggers: unexpected record found for rel %s", RelationGetRelationName(relation)); - - if (triggers == NULL) - triggers = (Trigger *) MemoryContextAlloc(CacheMemoryContext, - sizeof(Trigger)); - else - triggers = (Trigger *) repalloc(triggers, - (found + 1) * sizeof(Trigger)); build = &(triggers[found]); build->tgoid = htup->t_data->t_oid; @@ -730,6 +745,9 @@ equalTriggerDescs(TriggerDesc *trigdesc1, TriggerDesc *trigdesc2) * We need not examine the "index" data, just the trigger array * itself; if we have the same triggers with the same types, the * derived index data should match. + * + * As of 7.3 we assume trigger set ordering is significant in the + * comparison; so we just compare corresponding slots of the two sets. */ if (trigdesc1 != NULL) { @@ -740,21 +758,9 @@ equalTriggerDescs(TriggerDesc *trigdesc1, TriggerDesc *trigdesc2) for (i = 0; i < trigdesc1->numtriggers; i++) { Trigger *trig1 = trigdesc1->triggers + i; - Trigger *trig2 = NULL; + Trigger *trig2 = trigdesc2->triggers + i; - /* - * We can't assume that the triggers are always read from - * pg_trigger in the same order; so use the trigger OIDs to - * identify the triggers to compare. (We assume here that the - * same OID won't appear twice in either trigger set.) - */ - for (j = 0; j < trigdesc2->numtriggers; j++) - { - trig2 = trigdesc2->triggers + j; - if (trig1->tgoid == trig2->tgoid) - break; - } - if (j >= trigdesc2->numtriggers) + if (trig1->tgoid != trig2->tgoid) return false; if (strcmp(trig1->tgname, trig2->tgname) != 0) return false; diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index 686fcc8416..983055ef78 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.161 2002/04/18 20:01:09 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.162 2002/04/19 16:36:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -635,10 +635,10 @@ RelationBuildRuleLock(Relation relation) { MemoryContext rulescxt; MemoryContext oldcxt; - HeapTuple pg_rewrite_tuple; - Relation pg_rewrite_desc; - TupleDesc pg_rewrite_tupdesc; - SysScanDesc pg_rewrite_scan; + HeapTuple rewrite_tuple; + Relation rewrite_desc; + TupleDesc rewrite_tupdesc; + SysScanDesc rewrite_scan; ScanKeyData key; RuleLock *rulelock; int numlocks; @@ -657,7 +657,7 @@ RelationBuildRuleLock(Relation relation) relation->rd_rulescxt = rulescxt; /* - * form an array to hold the rewrite rules (the array is extended if + * allocate an array to hold the rewrite rules (the array is extended if * necessary) */ maxlocks = 4; @@ -675,18 +675,22 @@ RelationBuildRuleLock(Relation relation) /* * open pg_rewrite and begin a scan + * + * Note: since we scan the rules using RewriteRelRulenameIndex, + * we will be reading the rules in name order, except possibly + * during emergency-recovery operations (ie, IsIgnoringSystemIndexes). + * This in turn ensures that rules will be fired in name order. */ - pg_rewrite_desc = heap_openr(RewriteRelationName, AccessShareLock); - pg_rewrite_tupdesc = RelationGetDescr(pg_rewrite_desc); - pg_rewrite_scan = systable_beginscan(pg_rewrite_desc, - RewriteRelRulenameIndex, - criticalRelcachesBuilt, - SnapshotNow, - 1, &key); + rewrite_desc = heap_openr(RewriteRelationName, AccessShareLock); + rewrite_tupdesc = RelationGetDescr(rewrite_desc); + rewrite_scan = systable_beginscan(rewrite_desc, + RewriteRelRulenameIndex, + true, SnapshotNow, + 1, &key); - while (HeapTupleIsValid(pg_rewrite_tuple = systable_getnext(pg_rewrite_scan))) + while (HeapTupleIsValid(rewrite_tuple = systable_getnext(rewrite_scan))) { - Form_pg_rewrite rewrite_form = (Form_pg_rewrite) GETSTRUCT(pg_rewrite_tuple); + Form_pg_rewrite rewrite_form = (Form_pg_rewrite) GETSTRUCT(rewrite_tuple); bool isnull; Datum ruleaction; Datum rule_evqual; @@ -697,7 +701,7 @@ RelationBuildRuleLock(Relation relation) rule = (RewriteRule *) MemoryContextAlloc(rulescxt, sizeof(RewriteRule)); - rule->ruleId = pg_rewrite_tuple->t_data->t_oid; + rule->ruleId = rewrite_tuple->t_data->t_oid; rule->event = rewrite_form->ev_type - '0'; rule->attrno = rewrite_form->ev_attr; @@ -705,9 +709,9 @@ RelationBuildRuleLock(Relation relation) /* Must use heap_getattr to fetch ev_qual and ev_action */ - ruleaction = heap_getattr(pg_rewrite_tuple, + ruleaction = heap_getattr(rewrite_tuple, Anum_pg_rewrite_ev_action, - pg_rewrite_tupdesc, + rewrite_tupdesc, &isnull); Assert(!isnull); ruleaction_str = DatumGetCString(DirectFunctionCall1(textout, @@ -717,13 +721,13 @@ RelationBuildRuleLock(Relation relation) MemoryContextSwitchTo(oldcxt); pfree(ruleaction_str); - rule_evqual = heap_getattr(pg_rewrite_tuple, + rule_evqual = heap_getattr(rewrite_tuple, Anum_pg_rewrite_ev_qual, - pg_rewrite_tupdesc, + rewrite_tupdesc, &isnull); Assert(!isnull); rule_evqual_str = DatumGetCString(DirectFunctionCall1(textout, - rule_evqual)); + rule_evqual)); oldcxt = MemoryContextSwitchTo(rulescxt); rule->qual = (Node *) stringToNode(rule_evqual_str); MemoryContextSwitchTo(oldcxt); @@ -741,8 +745,8 @@ RelationBuildRuleLock(Relation relation) /* * end the scan and close the attribute relation */ - systable_endscan(pg_rewrite_scan); - heap_close(pg_rewrite_desc, AccessShareLock); + systable_endscan(rewrite_scan); + heap_close(rewrite_desc, AccessShareLock); /* * form a RuleLock and insert into relation @@ -764,9 +768,13 @@ RelationBuildRuleLock(Relation relation) static bool equalRuleLocks(RuleLock *rlock1, RuleLock *rlock2) { - int i, - j; + int i; + /* + * As of 7.3 we assume the rule ordering is repeatable, + * because RelationBuildRuleLock should read 'em in a + * consistent order. So just compare corresponding slots. + */ if (rlock1 != NULL) { if (rlock2 == NULL) @@ -776,21 +784,9 @@ equalRuleLocks(RuleLock *rlock1, RuleLock *rlock2) for (i = 0; i < rlock1->numLocks; i++) { RewriteRule *rule1 = rlock1->rules[i]; - RewriteRule *rule2 = NULL; + RewriteRule *rule2 = rlock2->rules[i]; - /* - * We can't assume that the rules are always read from - * pg_rewrite in the same order; so use the rule OIDs to - * identify the rules to compare. (We assume here that the - * same OID won't appear twice in either ruleset.) - */ - for (j = 0; j < rlock2->numLocks; j++) - { - rule2 = rlock2->rules[j]; - if (rule1->ruleId == rule2->ruleId) - break; - } - if (j >= rlock2->numLocks) + if (rule1->ruleId != rule2->ruleId) return false; if (rule1->event != rule2->event) return false; diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index 4d6742fdbd..73ecb7fc6b 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -37,7 +37,7 @@ * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: catversion.h,v 1.118 2002/04/18 20:01:10 tgl Exp $ + * $Id: catversion.h,v 1.119 2002/04/19 16:36:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -53,6 +53,6 @@ */ /* yyyymmddN */ -#define CATALOG_VERSION_NO 200204181 +#define CATALOG_VERSION_NO 200204182 #endif diff --git a/src/include/catalog/indexing.h b/src/include/catalog/indexing.h index e08e3aa8e9..0ee35e3525 100644 --- a/src/include/catalog/indexing.h +++ b/src/include/catalog/indexing.h @@ -8,7 +8,7 @@ * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: indexing.h,v 1.65 2002/04/18 20:01:10 tgl Exp $ + * $Id: indexing.h,v 1.66 2002/04/19 16:36:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -86,7 +86,7 @@ #define StatisticRelidAttnumIndex "pg_statistic_relid_att_index" #define TriggerConstrNameIndex "pg_trigger_tgconstrname_index" #define TriggerConstrRelidIndex "pg_trigger_tgconstrrelid_index" -#define TriggerRelidIndex "pg_trigger_tgrelid_index" +#define TriggerRelidNameIndex "pg_trigger_tgrelid_tgname_index" #define TriggerOidIndex "pg_trigger_oid_index" #define TypeNameNspIndex "pg_type_typname_nsp_index" #define TypeOidIndex "pg_type_oid_index" @@ -182,9 +182,11 @@ DECLARE_UNIQUE_INDEX(pg_rewrite_rel_rulename_index on pg_rewrite using btree(ev_ DECLARE_UNIQUE_INDEX(pg_shadow_usename_index on pg_shadow using btree(usename name_ops)); DECLARE_UNIQUE_INDEX(pg_shadow_usesysid_index on pg_shadow using btree(usesysid int4_ops)); DECLARE_UNIQUE_INDEX(pg_statistic_relid_att_index on pg_statistic using btree(starelid oid_ops, staattnum int2_ops)); +/* This following index is not used for a cache and is not unique */ DECLARE_INDEX(pg_trigger_tgconstrname_index on pg_trigger using btree(tgconstrname name_ops)); +/* This following index is not used for a cache and is not unique */ DECLARE_INDEX(pg_trigger_tgconstrrelid_index on pg_trigger using btree(tgconstrrelid oid_ops)); -DECLARE_INDEX(pg_trigger_tgrelid_index on pg_trigger using btree(tgrelid oid_ops)); +DECLARE_UNIQUE_INDEX(pg_trigger_tgrelid_tgname_index on pg_trigger using btree(tgrelid oid_ops, tgname name_ops)); DECLARE_UNIQUE_INDEX(pg_trigger_oid_index on pg_trigger using btree(oid oid_ops)); DECLARE_UNIQUE_INDEX(pg_type_oid_index on pg_type using btree(oid oid_ops)); DECLARE_UNIQUE_INDEX(pg_type_typname_nsp_index on pg_type using btree(typname name_ops, typnamespace oid_ops)); diff --git a/src/test/regress/expected/foreign_key.out b/src/test/regress/expected/foreign_key.out index 0d0b6a6cb8..7f4c5f8561 100644 --- a/src/test/regress/expected/foreign_key.out +++ b/src/test/regress/expected/foreign_key.out @@ -899,7 +899,7 @@ delete from pktable where base1=2; ERROR: referential integrity violation - key in pktable still referenced from pktable -- fails (1,1) is being referenced (twice) update pktable set base1=3 where base1=1; -ERROR: referential integrity violation - key in pktable still referenced from pktable +ERROR: referential integrity violation - key referenced from pktable not found in pktable -- this sequence of two deletes will work, since after the first there will be no (2,*) references delete from pktable where base2=2; delete from pktable where base1=2;