Error out if inheriting a distributed table (#4871)

* Error out if inheriting a distributed table

* Add test inheriting a distirbuted table

src/backend/distributed/commands/table.c

@@ -184,10 +184,32 @@ PostprocessCreateTableStmt(CreateStmt *createStatement, const char *queryString)
 {
 	PostprocessCreateTableStmtForeignKeys(createStatement);
 
-	if (createStatement->inhRelations != NIL && createStatement->partbound != NULL)
+	if (createStatement->inhRelations != NIL)
 	{
-		/* process CREATE TABLE ... PARTITION OF command */
+		if (createStatement->partbound != NULL)
-		PostprocessCreateTableStmtPartitionOf(createStatement, queryString);
+		{
+			/* process CREATE TABLE ... PARTITION OF command */
+			PostprocessCreateTableStmtPartitionOf(createStatement, queryString);
+		}
+		else
+		{
+			/* process CREATE TABLE ... INHERITS ... */
+			RangeVar *parentRelation = NULL;
+			foreach_ptr(parentRelation, createStatement->inhRelations)
+			{
+				bool missingOk = false;
+				Oid parentRelationId = RangeVarGetRelid(parentRelation, NoLock,
+														missingOk);
+				Assert(parentRelationId != InvalidOid);
+
+				if (IsCitusTable(parentRelationId))
+				{
+					/* here we error out if inheriting a distributed table */
+					ereport(ERROR, (errmsg("non-distributed tables cannot inherit "
+										   "distributed tables")));
+				}
+			}
+		}
 	}
 }
 

src/test/regress/expected/multi_partitioning.out

@@ -2067,6 +2067,17 @@ SELECT * FROM time_partition_range('list_partitioned_p1');
 ERROR:  relation "list_partitioned_p1" is not a range partition
 DETAIL:  time_partition_range can only be used for partitions of range-partitioned tables with a single partition column
 DROP TABLE list_partitioned;
+-- error out when inheriting a distributed table
+CREATE TABLE test_inheritance(a int, b int);
+SELECT create_distributed_table('test_inheritance','a');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+CREATE TABLE local_inheritance (k int) INHERITS (test_inheritance);
+ERROR:  non-distributed tables cannot inherit distributed tables
+DROP TABLE test_inheritance;
 DROP SCHEMA partitioning_schema CASCADE;
 NOTICE:  drop cascades to table partitioning_schema."schema-test"
 DROP TABLE IF EXISTS

src/test/regress/sql/multi_partitioning.sql

@@ -1219,6 +1219,12 @@ SELECT parent_table, partition_column, partition, from_value, to_value FROM time
 SELECT * FROM time_partition_range('list_partitioned_p1');
 DROP TABLE list_partitioned;
 
+-- error out when inheriting a distributed table
+CREATE TABLE test_inheritance(a int, b int);
+SELECT create_distributed_table('test_inheritance','a');
+CREATE TABLE local_inheritance (k int) INHERITS (test_inheritance);
+DROP TABLE test_inheritance;
+
 DROP SCHEMA partitioning_schema CASCADE;
 DROP TABLE IF EXISTS
 	partitioning_hash_test,