wip

src/backend/distributed/commands/database.c

@@ -632,13 +632,11 @@ List *
 PreprocessDropDatabaseStmt(Node *node, const char *queryString,
 						   ProcessUtilityContext processUtilityContext)
 {
-	if (!EnableCreateDatabasePropagation || !ShouldPropagate())
+	if (!IsDistributedDropDatabaseCommand(node))
 	{
 		return NIL;
 	}
 
-	EnsurePropagationToCoordinator();
-
 	DropdbStmt *stmt = (DropdbStmt *) node;
 
 	bool isPostProcess = false;
@@ -657,22 +655,78 @@ PreprocessDropDatabaseStmt(Node *node, const char *queryString,
 		return NIL;
 	}
 
+	EnsurePropagationToCoordinator();
+
 	SerializeDistributedDDLsOnObjectClassObject(OCLASS_DATABASE, stmt->dbname);
 
-	char *dropDatabaseCommand = DeparseTreeNode(node);
+	OperationId operationId = RegisterOperationNeedingCleanup();
 
-	List *dropDatabaseCommands = list_make3(DISABLE_DDL_PROPAGATION,
-											(void *) dropDatabaseCommand,
+	char *tempDatabaseName = psprintf(TEMP_DATABASE_NAME_FMT,
+									  operationId, GetLocalGroupId());
+
+	UnmarkObjectDistributed(linitial(addresses));
+
+	char *unmarkObjectDistributedCommand =
+		psprintf("SELECT pg_catalog.citus_unmark_object_distributed("
+				 "(SELECT oid FROM pg_class WHERE relname = 'pg_database'), "
+				 "(SELECT oid FROM pg_database WHERE datname = %s), "
+				 "0);",
+				 quote_literal_cstr(tempDatabaseName));
+	List *unmarkObjectDistributedCommands = list_make1(unmarkObjectDistributedCommand);
+	List *unmarkObjectDistributedDDLJobList =
+		NodeDDLTaskList(REMOTE_NODES, unmarkObjectDistributedCommands);
+
+	char *renameDatabaseCommand =
+		psprintf("ALTER DATABASE %s RENAME TO %s",
+				 quote_identifier(stmt->dbname),
+				 quote_identifier(tempDatabaseName));
+
+	int saveNestLevel = NewGUCNestLevel();
+	set_config_option("citus.enable_ddl_propagation", "off",
+					  (superuser() ? PGC_SUSET : PGC_USERSET), PGC_S_SESSION,
+					  GUC_ACTION_LOCAL, true, 0, false);
+
+	ExecuteUtilityCommand(renameDatabaseCommand);
+
+	AtEOXact_GUC(true, saveNestLevel);
+
+	List *renameDatabaseCommands = list_make3(DISABLE_DDL_PROPAGATION,
+											  renameDatabaseCommand,
 											  ENABLE_DDL_PROPAGATION);
 
-	/*
-	 * Due to same reason stated in PostprocessCreateDatabaseStmt(), we need to
-	 * use NontransactionalNodeDDLTaskList() to send the DROP DATABASE statement
-	 * to the workers.
-	 */
-	List *dropDatabaseDDLJobList =
-		NontransactionalNodeDDLTaskList(REMOTE_NODES, dropDatabaseCommands);
-	return dropDatabaseDDLJobList;
+	List *renameDatabaseDDLJobList =
+		NodeDDLTaskList(REMOTE_NODES, renameDatabaseCommands);
+
+	List *allNodes = TargetWorkerSetNodeList(ALL_SHARD_NODES, RowShareLock);
+	WorkerNode *workerNode = NULL;
+	foreach_ptr(workerNode, allNodes)
+	{
+		InsertCleanupRecordInCurrentTransaction(
+			CLEANUP_OBJECT_DATABASE,
+			pstrdup(quote_identifier(tempDatabaseName)),
+			workerNode->groupId,
+			CLEANUP_DEFERRED_ON_SUCCESS
+			);
+	}
+
+	return list_concat(renameDatabaseDDLJobList, unmarkObjectDistributedDDLJobList);
+}
+
+
+bool
+IsDistributedDropDatabaseCommand(Node *node)
+{
+	if (!IsA(node, DropdbStmt))
+	{
+		return false;
+	}
+
+	if (!EnableCreateDatabasePropagation || !ShouldPropagate())
+	{
+		return false;
+	}
+
+	return true;
 }
 
 

src/backend/distributed/commands/utility_hook.c

@@ -115,6 +115,7 @@ static void citus_ProcessUtilityInternal(PlannedStmt *pstmt,
 										 struct QueryEnvironment *queryEnv,
 										 DestReceiver *dest,
 										 QueryCompletion *completionTag);
+static bool ShouldSkipPrevProcessUtility(Node *node);
 static void set_indexsafe_procflags(void);
 static char * CurrentSearchPath(void);
 static void IncrementUtilityHookCountersIfNecessary(Node *parsetree);
@@ -785,8 +786,11 @@ citus_ProcessUtilityInternal(PlannedStmt *pstmt,
 			PreprocessAlterExtensionCitusStmtForCitusColumnar(parsetree);
 		}
 
+		if (!ShouldSkipPrevProcessUtility(parsetree))
+		{
 			PrevProcessUtility(pstmt, queryString, false, context,
 							   params, queryEnv, dest, completionTag);
+		}
 
 		if (isAlterExtensionUpdateCitusStmt)
 		{
@@ -947,6 +951,13 @@ citus_ProcessUtilityInternal(PlannedStmt *pstmt,
 }
 
 
+static bool
+ShouldSkipPrevProcessUtility(Node *node)
+{
+	return IsDistributedDropDatabaseCommand(node);
+}
+
+
 /*
  * UndistributeDisconnectedCitusLocalTables undistributes citus local tables that
  * are not connected to any reference tables via their individual foreign key

src/backend/distributed/metadata/distobject.c

@@ -119,19 +119,6 @@ citus_unmark_object_distributed(PG_FUNCTION_ARGS)
 		PG_RETURN_VOID();
 	}
 
-	if (ObjectExists(&address))
-	{
-		ereport(ERROR, (errmsg("object still exists"),
-						errdetail("the %s \"%s\" still exists",
-								  getObjectTypeDescription(&address,
-
-		                                                   /* missingOk: */ false),
-								  getObjectIdentity(&address,
-
-		                                            /* missingOk: */ false)),
-						errhint("drop the object via a DROP command")));
-	}
-
 	UnmarkObjectDistributed(&address);
 
 	PG_RETURN_VOID();
@@ -457,19 +444,6 @@ UnmarkNodeWideObjectsDistributed(Node *node)
 			UnmarkRolesDistributed(distributedDropRoles);
 		}
 	}
-	else if (IsA(node, DropdbStmt))
-	{
-		DropdbStmt *stmt = castNode(DropdbStmt, node);
-		char *dbName = stmt->dbname;
-
-		Oid dbOid = get_database_oid(dbName, stmt->missing_ok);
-		ObjectAddress *dbObjectAddress = palloc0(sizeof(ObjectAddress));
-		ObjectAddressSet(*dbObjectAddress, DatabaseRelationId, dbOid);
-		if (IsAnyObjectDistributed(list_make1(dbObjectAddress)))
-		{
-			UnmarkObjectDistributed(dbObjectAddress);
-		}
-	}
 }
 
 

src/include/distributed/commands.h

@@ -241,6 +241,7 @@ extern List * PreprocessCreateDatabaseStmt(Node *node, const char *queryString,
 extern List * PostprocessCreateDatabaseStmt(Node *node, const char *queryString);
 extern List * PreprocessDropDatabaseStmt(Node *node, const char *queryString,
 										 ProcessUtilityContext processUtilityContext);
+extern bool IsDistributedDropDatabaseCommand(Node *node);
 extern List * DropDatabaseStmtObjectAddress(Node *node, bool missingOk,
 											bool isPostprocess);
 extern List * CreateDatabaseStmtObjectAddress(Node *node, bool missingOk,