Do distributed check first, for DropSchema stmts

src/backend/distributed/commands/schema.c

@@ -86,13 +86,6 @@ PreprocessDropSchemaStmt(Node *node, const char *queryString,
 	DropStmt *dropStatement = castNode(DropStmt, node);
 	Assert(dropStatement->removeType == OBJECT_SCHEMA);
 
-	if (!ShouldPropagate())
-	{
-		return NIL;
-	}
-
-	EnsureCoordinator();
-
 	List *distributedSchemas = FilterDistributedSchemas(dropStatement->objects);
 
 	if (list_length(distributedSchemas) < 1)
@@ -100,6 +93,13 @@ PreprocessDropSchemaStmt(Node *node, const char *queryString,
 		return NIL;
 	}
 
+	if (!ShouldPropagate())
+	{
+		return NIL;
+	}
+
+	EnsureCoordinator();
+
 	EnsureSequentialMode(OBJECT_SCHEMA);
 
 	Value *schemaVal = NULL;

src/test/regress/expected/multi_mx_schema_support.out

@@ -515,12 +515,30 @@ SELECT table_schema AS "Shards' Schema"
  mx_new_schema
 (1 row)
 
+-- check that we can drop a user-defined schema from workers
+SET citus.enable_ddl_propagation TO OFF;
+CREATE SCHEMA localschema;
+RESET citus.enable_ddl_propagation;
+DROP SCHEMA localschema;
 \c - - - :master_port
 SELECT * FROM mx_new_schema.table_set_schema;
  id
 ---------------------------------------------------------------------
 (0 rows)
 
+-- verify local schema does not exist on the worker
+-- worker errors out as "schema does not exist"
+SET citus.enable_ddl_propagation TO OFF;
+CREATE SCHEMA localschema;
+-- should error out
+SELECT run_command_on_workers($$DROP SCHEMA localschema;$$);
+                       run_command_on_workers
+---------------------------------------------------------------------
+ (localhost,57637,f,"ERROR:  schema ""localschema"" does not exist")
+ (localhost,57638,f,"ERROR:  schema ""localschema"" does not exist")
+(2 rows)
+
+RESET citus.enable_ddl_propagation;
 DROP SCHEMA mx_old_schema CASCADE;
 DROP SCHEMA mx_new_schema CASCADE;
 NOTICE:  drop cascades to table mx_new_schema.table_set_schema

src/test/regress/sql/multi_mx_schema_support.sql

@@ -333,8 +333,25 @@ SELECT table_schema AS "Shards' Schema"
     FROM information_schema.tables
     WHERE table_name LIKE 'table\_set\_schema\_%'
     GROUP BY table_schema;
+
+-- check that we can drop a user-defined schema from workers
+SET citus.enable_ddl_propagation TO OFF;
+CREATE SCHEMA localschema;
+RESET citus.enable_ddl_propagation;
+DROP SCHEMA localschema;
+
 \c - - - :master_port
 SELECT * FROM mx_new_schema.table_set_schema;
 
+-- verify local schema does not exist on the worker
+-- worker errors out as "schema does not exist"
+SET citus.enable_ddl_propagation TO OFF;
+CREATE SCHEMA localschema;
+
+-- should error out
+SELECT run_command_on_workers($$DROP SCHEMA localschema;$$);
+
+RESET citus.enable_ddl_propagation;
+
 DROP SCHEMA mx_old_schema CASCADE;
 DROP SCHEMA mx_new_schema CASCADE;