Avoid having two PKs in a partition

If a table containing a primary key is attach as partition to a
partitioned table which has a primary key with a different definition,
we would happily create a second one in the new partition.  Oops.  It
turns out that this is because an error check in DefineIndex is executed
only if you tell it that it's being run by ALTER TABLE, and the original
code here wasn't.  Change it so that it does.

Added a couple of test cases for this, also.  A previously working test
started to fail in a different way than before patch because the new
check is called earlier; change the PK to plain UNIQUE so that the new
behavior isn't invoked, so that the test continues to verify what we
want it to verify.

Reported by: Noriyoshi Shinoda
Discussion: https://postgr.es/m/DF4PR8401MB102060EC2615EC9227CC73F7EEDF0@DF4PR8401MB1020.NAMPRD84.PROD.OUTLOOK.COM

src/backend/commands/indexcmds.c

@@ -973,7 +973,7 @@ DefineIndex(Oid relationId,
 								InvalidOid,			/* no predefined OID */
 								indexRelationId,	/* this is our child */
 								createdConstraintId,
-								false, check_rights, check_not_in_use,
+								is_alter_table, check_rights, check_not_in_use,
 								false, quiet);
 				}
 

src/backend/commands/tablecmds.c

@@ -14256,7 +14256,7 @@ AttachPartitionEnsureIndexes(Relation rel, Relation attachrel)
 			DefineIndex(RelationGetRelid(attachrel), stmt, InvalidOid,
 						RelationGetRelid(idxRel),
 						constraintOid,
-						false, false, false, false, false);
+						true, false, false, false, false);
 		}
 
 		index_close(idxRel, AccessShareLock);

src/test/regress/expected/indexing.out

@@ -878,7 +878,7 @@ select conname, contype, conrelid::regclass, conindid::regclass, conkey
 
 drop table idxpart;
 -- Verify that multi-layer partitioning honors the requirement that all
--- columns in the partition key must appear in primary key
+-- columns in the partition key must appear in primary/unique key
 create table idxpart (a int, b int, primary key (a)) partition by range (a);
 create table idxpart2 partition of idxpart
 for values from (0) to (1000) partition by range (b); -- fail
@@ -886,12 +886,12 @@ ERROR:  insufficient columns in PRIMARY KEY constraint definition
 DETAIL:  PRIMARY KEY constraint on table "idxpart2" lacks column "b" which is part of the partition key.
 drop table idxpart;
 -- Ditto for the ATTACH PARTITION case
-create table idxpart (a int primary key, b int) partition by range (a);
-create table idxpart1 (a int not null, b int, primary key (a, b))
+create table idxpart (a int unique, b int) partition by range (a);
+create table idxpart1 (a int not null, b int, unique (a, b))
   partition by range (a, b);
 alter table idxpart attach partition idxpart1 for values from (1) to (1000);
-ERROR:  insufficient columns in PRIMARY KEY constraint definition
-DETAIL:  PRIMARY KEY constraint on table "idxpart1" lacks column "b" which is part of the partition key.
+ERROR:  insufficient columns in UNIQUE constraint definition
+DETAIL:  UNIQUE constraint on table "idxpart1" lacks column "b" which is part of the partition key.
 DROP TABLE idxpart, idxpart1;
 -- Multi-layer partitioning works correctly in this case:
 create table idxpart (a int, b int, primary key (a, b)) partition by range (a);
@@ -952,6 +952,22 @@ select indrelid::regclass, indexrelid::regclass, inhparent::regclass, indisvalid
 (0 rows)
 
 drop table idxpart;
+-- If the partition to be attached already has a primary key, fail if
+-- it doesn't match the parent's PK.
+CREATE TABLE idxpart (c1 INT PRIMARY KEY, c2 INT, c3 VARCHAR(10)) PARTITION BY RANGE(c1);
+CREATE TABLE idxpart1 (LIKE idxpart);
+ALTER TABLE idxpart1 ADD PRIMARY KEY (c1, c2);
+ALTER TABLE idxpart ATTACH PARTITION idxpart1 FOR VALUES FROM (100) TO (200);
+ERROR:  multiple primary keys for table "idxpart1" are not allowed
+DROP TABLE idxpart, idxpart1;
+-- Ditto if there is some distance between the PKs (subpartitioning)
+create table idxpart (a int, b int, primary key (a)) partition by range (a);
+create table idxpart1 (a int not null, b int) partition by range (a);
+create table idxpart11 (a int not null, b int primary key);
+alter table idxpart1 attach partition idxpart11 for values from (0) to (1000);
+alter table idxpart attach partition idxpart1 for values from (0) to (10000);
+ERROR:  multiple primary keys for table "idxpart11" are not allowed
+drop table idxpart, idxpart1, idxpart11;
 -- If a partitioned table has a constraint whose index is not valid,
 -- attaching a missing partition makes it valid.
 create table idxpart (a int) partition by range (a);

src/test/regress/sql/indexing.sql

@@ -444,15 +444,15 @@ select conname, contype, conrelid::regclass, conindid::regclass, conkey
 drop table idxpart;
 
 -- Verify that multi-layer partitioning honors the requirement that all
--- columns in the partition key must appear in primary key
+-- columns in the partition key must appear in primary/unique key
 create table idxpart (a int, b int, primary key (a)) partition by range (a);
 create table idxpart2 partition of idxpart
 for values from (0) to (1000) partition by range (b); -- fail
 drop table idxpart;
 
 -- Ditto for the ATTACH PARTITION case
-create table idxpart (a int primary key, b int) partition by range (a);
-create table idxpart1 (a int not null, b int, primary key (a, b))
+create table idxpart (a int unique, b int) partition by range (a);
+create table idxpart1 (a int not null, b int, unique (a, b))
   partition by range (a, b);
 alter table idxpart attach partition idxpart1 for values from (1) to (1000);
 DROP TABLE idxpart, idxpart1;
@@ -494,6 +494,22 @@ select indrelid::regclass, indexrelid::regclass, inhparent::regclass, indisvalid
   order by indexrelid::regclass::text collate "C";
 drop table idxpart;
 
+-- If the partition to be attached already has a primary key, fail if
+-- it doesn't match the parent's PK.
+CREATE TABLE idxpart (c1 INT PRIMARY KEY, c2 INT, c3 VARCHAR(10)) PARTITION BY RANGE(c1);
+CREATE TABLE idxpart1 (LIKE idxpart);
+ALTER TABLE idxpart1 ADD PRIMARY KEY (c1, c2);
+ALTER TABLE idxpart ATTACH PARTITION idxpart1 FOR VALUES FROM (100) TO (200);
+DROP TABLE idxpart, idxpart1;
+
+-- Ditto if there is some distance between the PKs (subpartitioning)
+create table idxpart (a int, b int, primary key (a)) partition by range (a);
+create table idxpart1 (a int not null, b int) partition by range (a);
+create table idxpart11 (a int not null, b int primary key);
+alter table idxpart1 attach partition idxpart11 for values from (0) to (1000);
+alter table idxpart attach partition idxpart1 for values from (0) to (10000);
+drop table idxpart, idxpart1, idxpart11;
+
 -- If a partitioned table has a constraint whose index is not valid,
 -- attaching a missing partition makes it valid.
 create table idxpart (a int) partition by range (a);