Report a more useful error for reloptions on a partitioned table.

Previously, trying to set storage parameters on a partitioned table
always led to "unrecognized parameter foo", because the code expected
there might be some valid parameters; but there aren't any.  The docs
make clear that it's intended that there never will be any, so let's
replace this useless search with a more to-the-point message.

Simon Riggs and Karina Litskevich

Discussion: https://postgr.es/m/CANbhV-H=eZ9kTR9mUgKGK0Qv9uXP=U+dQg3rinQHfTdFMhBA2A@mail.gmail.com

src/backend/access/common/reloptions.c

@@ -1984,13 +1984,12 @@ build_local_reloptions(local_relopts *relopts, Datum options, bool validate)
 bytea *
 partitioned_table_reloptions(Datum reloptions, bool validate)
 {
-	/*
-	 * There are no options for partitioned tables yet, but this is able to do
-	 * some validation.
-	 */
-	return (bytea *) build_reloptions(reloptions, validate,
-									  RELOPT_KIND_PARTITIONED,
-									  0, NULL, 0);
+	if (validate && reloptions)
+		ereport(ERROR,
+				errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				errmsg("cannot specify storage parameters for a partitioned table"),
+				errhint("Specify storage parameters for its leaf partitions, instead."));
+	return NULL;
 }
 
 /*

src/test/regress/expected/alter_table.out

@@ -3801,6 +3801,10 @@ ALTER TABLE partitioned DROP COLUMN b;
 ERROR:  cannot drop column "b" because it is part of the partition key of relation "partitioned"
 ALTER TABLE partitioned ALTER COLUMN b TYPE char(5);
 ERROR:  cannot alter column "b" because it is part of the partition key of relation "partitioned"
+-- specifying storage parameters for partitioned tables is not supported
+ALTER TABLE partitioned SET (fillfactor=100);
+ERROR:  cannot specify storage parameters for a partitioned table
+HINT:  Specify storage parameters for its leaf partitions, instead.
 -- partitioned table cannot participate in regular inheritance
 CREATE TABLE nonpartitioned (
 	a int,

src/test/regress/expected/create_table.out

@@ -987,6 +987,10 @@ Partition key: LIST (a)
 Number of partitions: 0
 
 DROP TABLE parted_col_comment;
+-- specifying storage parameters for partitioned tables is not supported
+CREATE TABLE parted_col_comment (a int, b text) PARTITION BY LIST (a) WITH (fillfactor=100);
+ERROR:  cannot specify storage parameters for a partitioned table
+HINT:  Specify storage parameters for its leaf partitions, instead.
 -- list partitioning on array type column
 CREATE TABLE arrlp (a int[]) PARTITION BY LIST (a);
 CREATE TABLE arrlp12 PARTITION OF arrlp FOR VALUES IN ('{1}', '{2}');

src/test/regress/sql/alter_table.sql

@@ -2325,6 +2325,9 @@ ALTER TABLE partitioned ALTER COLUMN a TYPE char(5);
 ALTER TABLE partitioned DROP COLUMN b;
 ALTER TABLE partitioned ALTER COLUMN b TYPE char(5);
 
+-- specifying storage parameters for partitioned tables is not supported
+ALTER TABLE partitioned SET (fillfactor=100);
+
 -- partitioned table cannot participate in regular inheritance
 CREATE TABLE nonpartitioned (
 	a int,

src/test/regress/sql/create_table.sql

@@ -652,6 +652,9 @@ SELECT obj_description('parted_col_comment'::regclass);
 \d+ parted_col_comment
 DROP TABLE parted_col_comment;
 
+-- specifying storage parameters for partitioned tables is not supported
+CREATE TABLE parted_col_comment (a int, b text) PARTITION BY LIST (a) WITH (fillfactor=100);
+
 -- list partitioning on array type column
 CREATE TABLE arrlp (a int[]) PARTITION BY LIST (a);
 CREATE TABLE arrlp12 PARTITION OF arrlp FOR VALUES IN ('{1}', '{2}');