Fix failures in validateForeignKeyConstraint's slow path.

The foreign-key-checking loop in ATRewriteTables failed to ignore
relations without storage (e.g., partitioned tables), unlike the
initial loop.  This accidentally worked as long as RI_Initial_Check
succeeded, which it does in most practical cases (including all the
ones exercised in the existing regression tests :-().  However, if
that failed, as for instance when there are permissions issues,
then we entered the slow fire-the-trigger-on-each-tuple path.
And that would try to read from the referencing relation, and fail
if it lacks storage.

A second problem, recently introduced in HEAD, was that this loop
had been broken by sloppy refactoring for the tableam API changes.

Repair both issues, and add a regression test case so we have some
coverage on this code path.  Back-patch as needed to v11.

(It looks like this code could do with additional bulletproofing,
but let's get a working test case in place first.)

Hadi Moshayedi, Tom Lane, Andres Freund

Discussion: https://postgr.es/m/CAK=1=WrnNmBbe5D9sm3t0a6dnAq3cdbF1vXY816j1wsMqzC8bw@mail.gmail.com
Discussion: https://postgr.es/m/19030.1554574075@sss.pgh.pa.us
Discussion: https://postgr.es/m/20190325180405.jytoehuzkeozggxx%40alap3.anarazel.de

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index e842f9152b7da2616eeb56f9b346d24f7b9164f9..31fe40aa17b3aac6bcd48be2e7f311f4a61f6e8f 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -4459,13 +4459,8 @@ ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode)
        {
                AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
 
-               /*
-                * Foreign tables have no storage, nor do partitioned tables and
-                * indexes.
-                */
-               if (tab->relkind == RELKIND_FOREIGN_TABLE ||
-                       tab->relkind == RELKIND_PARTITIONED_TABLE ||
-                       tab->relkind == RELKIND_PARTITIONED_INDEX)
+               /* Relations without storage may be ignored here */
+               if (!RELKIND_HAS_STORAGE(tab->relkind))
                        continue;
 
                /*
@@ -4645,6 +4640,10 @@ ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode)
                Relation        rel = NULL;
                ListCell   *lcon;
 
+               /* Relations without storage may be ignored here too */
+               if (!RELKIND_HAS_STORAGE(tab->relkind))
+                       continue;
+
                foreach(lcon, tab->constraints)
                {
                        NewConstraint *con = lfirst(lcon);
@@ -9647,7 +9646,7 @@ validateForeignKeyConstraint(char *conname,
                trigdata.type = T_TriggerData;
                trigdata.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW;
                trigdata.tg_relation = rel;
-               trigdata.tg_trigtuple = ExecFetchSlotHeapTuple(slot, true, NULL);
+               trigdata.tg_trigtuple = ExecFetchSlotHeapTuple(slot, false, NULL);
                trigdata.tg_trigslot = slot;
                trigdata.tg_newtuple = NULL;
                trigdata.tg_trigger = &trig;

diff --git a/src/test/regress/expected/foreign_key.out b/src/test/regress/expected/foreign_key.out
index 620eb4392bed835d2771e0912e4119d54fdfaedd..3dd33f6aa16c1c88cbc6c7433b7b1f649c59cadd 100644 (file)
--- a/src/test/regress/expected/foreign_key.out
+++ b/src/test/regress/expected/foreign_key.out
@@ -1895,6 +1895,32 @@ INSERT INTO fk_notpartitioned_pk VALUES (1600, 601), (1600, 1601);
 ALTER TABLE fk_partitioned_fk ATTACH PARTITION fk_partitioned_fk_2
   FOR VALUES IN (1600);
 -- leave these tables around intentionally
+-- test the case when the referenced table is owned by a different user
+create role regress_other_partitioned_fk_owner;
+grant references on fk_notpartitioned_pk to regress_other_partitioned_fk_owner;
+set role regress_other_partitioned_fk_owner;
+create table other_partitioned_fk(a int, b int) partition by list (a);
+create table other_partitioned_fk_1 partition of other_partitioned_fk
+  for values in (2048);
+insert into other_partitioned_fk
+  select 2048, x from generate_series(1,10) x;
+-- this should fail
+alter table other_partitioned_fk add foreign key (a, b)
+  references fk_notpartitioned_pk(a, b);
+ERROR:  insert or update on table "other_partitioned_fk_1" violates foreign key constraint "other_partitioned_fk_a_b_fkey"
+DETAIL:  Key (a, b)=(2048, 1) is not present in table "fk_notpartitioned_pk".
+-- add the missing keys and retry
+reset role;
+insert into fk_notpartitioned_pk (a, b)
+  select 2048, x from generate_series(1,10) x;
+set role regress_other_partitioned_fk_owner;
+alter table other_partitioned_fk add foreign key (a, b)
+  references fk_notpartitioned_pk(a, b);
+-- clean up
+drop table other_partitioned_fk;
+reset role;
+revoke all on fk_notpartitioned_pk from regress_other_partitioned_fk_owner;
+drop role regress_other_partitioned_fk_owner;
 -- Test creating a constraint at the parent that already exists in partitions.
 -- There should be no duplicated constraints, and attempts to drop the
 -- constraint in partitions should raise appropriate errors.

diff --git a/src/test/regress/sql/foreign_key.sql b/src/test/regress/sql/foreign_key.sql
index 1a8685099e7c9739da65173d1369c4aba71910a9..672fce317f1dc7273ed6f63e98c7f277d58d6e29 100644 (file)
--- a/src/test/regress/sql/foreign_key.sql
+++ b/src/test/regress/sql/foreign_key.sql
@@ -1365,6 +1365,31 @@ ALTER TABLE fk_partitioned_fk ATTACH PARTITION fk_partitioned_fk_2
 
 -- leave these tables around intentionally
 
+-- test the case when the referenced table is owned by a different user
+create role regress_other_partitioned_fk_owner;
+grant references on fk_notpartitioned_pk to regress_other_partitioned_fk_owner;
+set role regress_other_partitioned_fk_owner;
+create table other_partitioned_fk(a int, b int) partition by list (a);
+create table other_partitioned_fk_1 partition of other_partitioned_fk
+  for values in (2048);
+insert into other_partitioned_fk
+  select 2048, x from generate_series(1,10) x;
+-- this should fail
+alter table other_partitioned_fk add foreign key (a, b)
+  references fk_notpartitioned_pk(a, b);
+-- add the missing keys and retry
+reset role;
+insert into fk_notpartitioned_pk (a, b)
+  select 2048, x from generate_series(1,10) x;
+set role regress_other_partitioned_fk_owner;
+alter table other_partitioned_fk add foreign key (a, b)
+  references fk_notpartitioned_pk(a, b);
+-- clean up
+drop table other_partitioned_fk;
+reset role;
+revoke all on fk_notpartitioned_pk from regress_other_partitioned_fk_owner;
+drop role regress_other_partitioned_fk_owner;
+
 -- Test creating a constraint at the parent that already exists in partitions.
 -- There should be no duplicated constraints, and attempts to drop the
 -- constraint in partitions should raise appropriate errors.