Fixes review comments

src/backend/distributed/commands/database.c

@@ -293,7 +293,7 @@ PreprocessAlterDatabaseStmt(Node *node, const char *queryString,
 		return NIL;
 	}
 
-	/* Since ALTER TABLE SET TABLESPACE statement is not supported */
+	/* Since ALTER DATABASE SET TABLESPACE statement is not supported */
 	/* inside a transaction block, we need to send the command to the */
 	/* main database directly to make it work */
 	if (!IsSetTablespaceStatement(stmt))

src/backend/distributed/commands/non_main_db_distribute_object_ops.c

@@ -378,7 +378,7 @@ AlterDbStmtCheckSupportedObjectType(Node *node)
 	}
 	else
 	{
-		return IsSetTablespaceStatement(stmt) && strcmp(stmt->dbname, MainDb) != 0;
+		return strcmp(stmt->dbname, MainDb) != 0;
 	}
 }