Allow ON UPDATE/DELETE SET DEFAULT plans to be cached.

Once upon a time, somebody was worried that cached RI plans wouldn't get
remade with new default values after ALTER TABLE ... SET DEFAULT, so they
didn't allow caching of plans for ON UPDATE/DELETE SET DEFAULT actions.
That time is long gone, though (and even at the time I doubt this was the
greatest hazard posed by ALTER TABLE...).  So allow these triggers to cache
their plans just like the others.

The cache_plan argument to ri_PlanCheck is now vestigial, since there
are no callers that don't pass "true"; but I left it alone in case there
is any future need for it.

diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index cd1bb262a3539e9737f26ffe1d0a9fe122ec166a..5b439aab6fb3126cd3cc6dc6d8129d56b22a70e2 100644 (file)
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -2155,12 +2155,12 @@ RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
                                elog(ERROR, "SPI_connect failed");
 
                        /*
-                        * Prepare a plan for the set default delete operation.
-                        * Unfortunately we need to do it on every invocation because the
-                        * default value could potentially change between calls.
+                        * Fetch or prepare a saved plan for the set default delete
+                        * operation
                         */
                        ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_SETDEFAULT_DEL_DOUPDATE);
 
+                       if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
                        {
                                StringInfoData querybuf;
                                StringInfoData qualbuf;
@@ -2207,9 +2207,9 @@ RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
                                }
                                appendStringInfoString(&querybuf, qualbuf.data);
 
-                               /* Prepare the plan, don't save it */
+                               /* Prepare and save the plan */
                                qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
-                                                                        &qkey, fk_rel, pk_rel, false);
+                                                                        &qkey, fk_rel, pk_rel, true);
                        }
 
                        /*
@@ -2239,7 +2239,7 @@ RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
                        return PointerGetDatum(NULL);
 
                        /*
-                        * Handle MATCH PARTIAL set null delete.
+                        * Handle MATCH PARTIAL set default delete.
                         */
                case FKCONSTR_MATCH_PARTIAL:
                        ereport(ERROR,
@@ -2348,12 +2348,12 @@ RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
                                elog(ERROR, "SPI_connect failed");
 
                        /*
-                        * Prepare a plan for the set default delete operation.
-                        * Unfortunately we need to do it on every invocation because the
-                        * default value could potentially change between calls.
+                        * Fetch or prepare a saved plan for the set default update
+                        * operation
                         */
                        ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_SETDEFAULT_UPD_DOUPDATE);
 
+                       if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
                        {
                                StringInfoData querybuf;
                                StringInfoData qualbuf;
@@ -2400,9 +2400,9 @@ RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
                                }
                                appendStringInfoString(&querybuf, qualbuf.data);
 
-                               /* Prepare the plan, don't save it */
+                               /* Prepare and save the plan */
                                qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
-                                                                        &qkey, fk_rel, pk_rel, false);
+                                                                        &qkey, fk_rel, pk_rel, true);
                        }
 
                        /*
@@ -2432,7 +2432,7 @@ RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
                        return PointerGetDatum(NULL);
 
                        /*
-                        * Handle MATCH PARTIAL set null delete.
+                        * Handle MATCH PARTIAL set default update.
                         */
                case FKCONSTR_MATCH_PARTIAL:
                        ereport(ERROR,

diff --git a/src/test/regress/expected/foreign_key.out b/src/test/regress/expected/foreign_key.out
index 305dfe20d47eaaa1343d338292ddcceb4e209ad1..a63a89f40bbea2d1109e5afd61d58f49dfeb1883 100644 (file)
--- a/src/test/regress/expected/foreign_key.out
+++ b/src/test/regress/expected/foreign_key.out
@@ -1319,3 +1319,39 @@ begin;
 (2 rows)
 
 commit;
+--
+-- Test that SET DEFAULT actions recognize updates to default values
+--
+create temp table defp (f1 int primary key);
+NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "defp_pkey" for table "defp"
+create temp table defc (f1 int default 0
+                        references defp on delete set default);
+insert into defp values (0), (1), (2);
+insert into defc values (2);
+select * from defc;
+ f1 
+----
+  2
+(1 row)
+
+delete from defp where f1 = 2;
+select * from defc;
+ f1 
+----
+  0
+(1 row)
+
+delete from defp where f1 = 0; -- fail
+ERROR:  update or delete on table "defp" violates foreign key constraint "defc_f1_fkey" on table "defc"
+DETAIL:  Key (f1)=(0) is still referenced from table "defc".
+alter table defc alter column f1 set default 1;
+delete from defp where f1 = 0;
+select * from defc;
+ f1 
+----
+  1
+(1 row)
+
+delete from defp where f1 = 1; -- fail
+ERROR:  update or delete on table "defp" violates foreign key constraint "defc_f1_fkey" on table "defc"
+DETAIL:  Key (f1)=(1) is still referenced from table "defc".

diff --git a/src/test/regress/sql/foreign_key.sql b/src/test/regress/sql/foreign_key.sql
index 874d9f7a331b4d30fe70c4262aa538aa17526807..43703d234e7fb990ad7bc12eafa943eedb800c07 100644 (file)
--- a/src/test/regress/sql/foreign_key.sql
+++ b/src/test/regress/sql/foreign_key.sql
@@ -943,3 +943,20 @@ begin;
     update selfref set a = 456 where a = 123;
     select a, b from selfref;
 commit;
+
+--
+-- Test that SET DEFAULT actions recognize updates to default values
+--
+create temp table defp (f1 int primary key);
+create temp table defc (f1 int default 0
+                        references defp on delete set default);
+insert into defp values (0), (1), (2);
+insert into defc values (2);
+select * from defc;
+delete from defp where f1 = 2;
+select * from defc;
+delete from defp where f1 = 0; -- fail
+alter table defc alter column f1 set default 1;
+delete from defp where f1 = 0;
+select * from defc;
+delete from defp where f1 = 1; -- fail