Avoid failure when altering state of partitioned foreign-key triggers.

Beginning in v15, if you apply ALTER TABLE ENABLE/DISABLE TRIGGER to
a partitioned table, it also affects the partitions' cloned versions
of the affected trigger(s).  The initial implementation of this
located the clones by name, but that fails on foreign-key triggers
which have names incorporating their own OIDs.  We can fix that, and
also make the behavior more bulletproof in the face of user-initiated
trigger renames, by identifying the cloned triggers by tgparentid.

Following the lead of earlier commits in this area, I took care not
to break ABI in the v15 branch, even though I rather doubt there
are any external callers of EnableDisableTrigger.

While here, update the documentation, which was not touched when
the semantics were changed.

Per bug #17817 from Alan Hodgson.  Back-patch to v15; older versions
do not have this behavior.

Discussion: https://postgr.es/m/17817-31dfb7c2100d9f3d@postgresql.org

Author: tglsfdc

doc/src/sgml/ref/alter_table.sgml

@@ -576,12 +576,12 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
      <para>
       These forms configure the firing of trigger(s) belonging to the table.
       A disabled trigger is still known to the system, but is not executed
-      when its triggering event occurs.  For a deferred trigger, the enable
+      when its triggering event occurs.  (For a deferred trigger, the enable
       status is checked when the event occurs, not when the trigger function
-      is actually executed.  One can disable or enable a single
+      is actually executed.)  One can disable or enable a single
       trigger specified by name, or all triggers on the table, or only
       user triggers (this option excludes internally generated constraint
-      triggers such as those that are used to implement foreign key
+      triggers, such as those that are used to implement foreign key
       constraints or deferrable uniqueness and exclusion constraints).
       Disabling or enabling internally generated constraint triggers
       requires superuser privileges; it should be done with caution since
@@ -603,14 +603,20 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
       The effect of this mechanism is that in the default configuration,
       triggers do not fire on replicas.  This is useful because if a trigger
       is used on the origin to propagate data between tables, then the
-      replication system will also replicate the propagated data, and the
+      replication system will also replicate the propagated data; so the
       trigger should not fire a second time on the replica, because that would
       lead to duplication.  However, if a trigger is used for another purpose
       such as creating external alerts, then it might be appropriate to set it
       to <literal>ENABLE ALWAYS</literal> so that it is also fired on
       replicas.
      </para>
 
+     <para>
+      When this command is applied to a partitioned table, the states of
+      corresponding clone triggers in the partitions are updated too,
+      unless <literal>ONLY</literal> is specified.
+     </para>
+
      <para>
       This command acquires a <literal>SHARE ROW EXCLUSIVE</literal> lock.
      </para>
@@ -1239,7 +1245,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
        <para>
         Disable or enable all triggers belonging to the table.
         (This requires superuser privilege if any of the triggers are
-        internally generated constraint triggers such as those that are used
+        internally generated constraint triggers, such as those that are used
         to implement foreign key constraints or deferrable uniqueness and
         exclusion constraints.)
        </para>
@@ -1251,7 +1257,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
       <listitem>
        <para>
         Disable or enable all triggers belonging to the table except for
-        internally generated constraint triggers such as those that are used
+        internally generated constraint triggers, such as those that are used
         to implement foreign key constraints or deferrable uniqueness and
         exclusion constraints.
        </para>
@@ -1504,9 +1510,12 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
     The actions for identity columns (<literal>ADD
     GENERATED</literal>, <literal>SET</literal> etc., <literal>DROP
     IDENTITY</literal>), as well as the actions
-    <literal>TRIGGER</literal>, <literal>CLUSTER</literal>, <literal>OWNER</literal>,
+    <literal>CLUSTER</literal>, <literal>OWNER</literal>,
     and <literal>TABLESPACE</literal> never recurse to descendant tables;
     that is, they always act as though <literal>ONLY</literal> were specified.
+    Actions affecting trigger states recurse to partitions of partitioned
+    tables (unless <literal>ONLY</literal> is specified), but never to
+    traditional-inheritance descendants.
     Adding a constraint recurses only for <literal>CHECK</literal> constraints
     that are not marked <literal>NO INHERIT</literal>.
    </para>

src/backend/commands/tablecmds.c

@@ -14726,7 +14726,8 @@ ATExecEnableDisableTrigger(Relation rel, const char *trigname,
 						   char fires_when, bool skip_system, bool recurse,
 						   LOCKMODE lockmode)
 {
-	EnableDisableTrigger(rel, trigname, fires_when, skip_system, recurse,
+	EnableDisableTrigger(rel, trigname, InvalidOid,
+						 fires_when, skip_system, recurse,
 						 lockmode);
 }
 

src/backend/commands/trigger.c

@@ -1715,7 +1715,8 @@ renametrig_partition(Relation tgrel, Oid partitionId, Oid parentTriggerOid,
  *	to change 'tgenabled' field for the specified trigger(s)
  *
  * rel: relation to process (caller must hold suitable lock on it)
- * tgname: trigger to process, or NULL to scan all triggers
+ * tgname: name of trigger to process, or NULL to scan all triggers
+ * tgparent: if not zero, process only triggers with this tgparentid
  * fires_when: new value for tgenabled field. In addition to generic
  *			   enablement/disablement, this also defines when the trigger
  *			   should be fired in session replication roles.
@@ -1727,7 +1728,7 @@ renametrig_partition(Relation tgrel, Oid partitionId, Oid parentTriggerOid,
  * system triggers
  */
 void
-EnableDisableTrigger(Relation rel, const char *tgname,
+EnableDisableTrigger(Relation rel, const char *tgname, Oid tgparent,
 					 char fires_when, bool skip_system, bool recurse,
 					 LOCKMODE lockmode)
 {
@@ -1766,6 +1767,9 @@ EnableDisableTrigger(Relation rel, const char *tgname,
 	{
 		Form_pg_trigger oldtrig = (Form_pg_trigger) GETSTRUCT(tuple);
 
+		if (OidIsValid(tgparent) && tgparent != oldtrig->tgparentid)
+			continue;
+
 		if (oldtrig->tgisinternal)
 		{
 			/* system trigger ... ok to process? */
@@ -1816,7 +1820,8 @@ EnableDisableTrigger(Relation rel, const char *tgname,
 				Relation	part;
 
 				part = relation_open(partdesc->oids[i], lockmode);
-				EnableDisableTrigger(part, NameStr(oldtrig->tgname),
+				/* Match on child triggers' tgparentid, not their name */
+				EnableDisableTrigger(part, NULL, oldtrig->oid,
 									 fires_when, skip_system, recurse,
 									 lockmode);
 				table_close(part, NoLock);	/* keep lock till commit */

src/include/commands/trigger.h

@@ -170,7 +170,7 @@ extern Oid	get_trigger_oid(Oid relid, const char *trigname, bool missing_ok);
 
 extern ObjectAddress renametrig(RenameStmt *stmt);
 
-extern void EnableDisableTrigger(Relation rel, const char *tgname,
+extern void EnableDisableTrigger(Relation rel, const char *tgname, Oid tgparent,
 								 char fires_when, bool skip_system, bool recurse,
 								 LOCKMODE lockmode);
 

src/test/regress/expected/triggers.out

@@ -2718,6 +2718,40 @@ select tgrelid::regclass, tgname, tgenabled from pg_trigger
  parent  | tg_stmt | A
 (3 rows)
 
+drop table parent, child1;
+-- Check processing of foreign key triggers
+create table parent (a int primary key, f int references parent)
+  partition by list (a);
+create table child1 partition of parent for values in (1);
+select tgrelid::regclass, rtrim(tgname, '0123456789') as tgname,
+  tgfoid::regproc, tgenabled
+  from pg_trigger where tgrelid in ('parent'::regclass, 'child1'::regclass)
+  order by tgrelid::regclass::text, tgfoid;
+ tgrelid |         tgname          |         tgfoid         | tgenabled 
+---------+-------------------------+------------------------+-----------
+ child1  | RI_ConstraintTrigger_c_ | "RI_FKey_check_ins"    | O
+ child1  | RI_ConstraintTrigger_c_ | "RI_FKey_check_upd"    | O
+ parent  | RI_ConstraintTrigger_c_ | "RI_FKey_check_ins"    | O
+ parent  | RI_ConstraintTrigger_c_ | "RI_FKey_check_upd"    | O
+ parent  | RI_ConstraintTrigger_a_ | "RI_FKey_noaction_del" | O
+ parent  | RI_ConstraintTrigger_a_ | "RI_FKey_noaction_upd" | O
+(6 rows)
+
+alter table parent disable trigger all;
+select tgrelid::regclass, rtrim(tgname, '0123456789') as tgname,
+  tgfoid::regproc, tgenabled
+  from pg_trigger where tgrelid in ('parent'::regclass, 'child1'::regclass)
+  order by tgrelid::regclass::text, tgfoid;
+ tgrelid |         tgname          |         tgfoid         | tgenabled 
+---------+-------------------------+------------------------+-----------
+ child1  | RI_ConstraintTrigger_c_ | "RI_FKey_check_ins"    | D
+ child1  | RI_ConstraintTrigger_c_ | "RI_FKey_check_upd"    | D
+ parent  | RI_ConstraintTrigger_c_ | "RI_FKey_check_ins"    | D
+ parent  | RI_ConstraintTrigger_c_ | "RI_FKey_check_upd"    | D
+ parent  | RI_ConstraintTrigger_a_ | "RI_FKey_noaction_del" | D
+ parent  | RI_ConstraintTrigger_a_ | "RI_FKey_noaction_upd" | D
+(6 rows)
+
 drop table parent, child1;
 -- Verify that firing state propagates correctly on creation, too
 CREATE TABLE trgfire (i int) PARTITION BY RANGE (i);

src/test/regress/sql/triggers.sql

@@ -1883,6 +1883,21 @@ select tgrelid::regclass, tgname, tgenabled from pg_trigger
   order by tgrelid::regclass::text, tgname;
 drop table parent, child1;
 
+-- Check processing of foreign key triggers
+create table parent (a int primary key, f int references parent)
+  partition by list (a);
+create table child1 partition of parent for values in (1);
+select tgrelid::regclass, rtrim(tgname, '0123456789') as tgname,
+  tgfoid::regproc, tgenabled
+  from pg_trigger where tgrelid in ('parent'::regclass, 'child1'::regclass)
+  order by tgrelid::regclass::text, tgfoid;
+alter table parent disable trigger all;
+select tgrelid::regclass, rtrim(tgname, '0123456789') as tgname,
+  tgfoid::regproc, tgenabled
+  from pg_trigger where tgrelid in ('parent'::regclass, 'child1'::regclass)
+  order by tgrelid::regclass::text, tgfoid;
+drop table parent, child1;
+
 -- Verify that firing state propagates correctly on creation, too
 CREATE TABLE trgfire (i int) PARTITION BY RANGE (i);
 CREATE TABLE trgfire1 PARTITION OF trgfire FOR VALUES FROM (1) TO (10);