Merge pull request #5440 from citusdata/default-add-to-metadata-experiment

Introduce GUC citus.use_citus_managed_tables

src/backend/distributed/commands/citus_add_local_table_to_metadata.c

@@ -46,6 +46,13 @@
 #include "utils/syscache.h"
 
 
+/*
+ * Global variable for the GUC citus.use_citus_managed_tables.
+ * This is used after every CREATE TABLE statement in utility_hook.c
+ * If this variable is set to true, we add all created tables to metadata.
+ */
+bool AddAllLocalTablesToMetadata = true;
+
 static void citus_add_local_table_to_metadata_internal(Oid relationId,
 													   bool cascadeViaForeignKeys);
 static void ErrorIfAddingPartitionTableToMetadata(Oid relationId);

src/backend/distributed/commands/table.c

@@ -2936,6 +2936,7 @@ ErrorIfUnsupportedAlterTableStmt(AlterTableStmt *alterTableStatement)
 
 			case AT_SetNotNull:
 			case AT_ReplicaIdentity:
+			case AT_ChangeOwner:
 			case AT_ValidateConstraint:
 			case AT_DropConstraint: /* we do the check for invalidation in AlterTableDropsForeignKey */
 #if PG_VERSION_NUM >= PG_VERSION_14

src/backend/distributed/commands/utility_hook.c

@@ -96,6 +96,7 @@ static void PostStandardProcessUtility(Node *parsetree);
 static void DecrementUtilityHookCountersIfNecessary(Node *parsetree);
 static bool IsDropSchemaOrDB(Node *parsetree);
 static bool ShouldCheckUndistributeCitusLocalTables(void);
+static bool ShouldAddNewTableToMetadata(Node *parsetree);
 
 
 /*
@@ -276,6 +277,28 @@ multi_ProcessUtility(PlannedStmt *pstmt,
 				UndistributeDisconnectedCitusLocalTables();
 			}
 			ResetConstraintDropped();
+
+			if (context == PROCESS_UTILITY_TOPLEVEL &&
+				ShouldAddNewTableToMetadata(parsetree))
+			{
+				/*
+				 * Here we need to increment command counter so that next command
+				 * can see the new table.
+				 */
+				CommandCounterIncrement();
+				CreateStmt *createTableStmt = (CreateStmt *) parsetree;
+				Oid relationId = RangeVarGetRelid(createTableStmt->relation,
+												  NoLock, false);
+
+				/*
+				 * Here we set autoConverted to false, since the user explicitly
+				 * wants these tables to be added to metadata, by setting the
+				 * GUC use_citus_managed_tables to true.
+				 */
+				bool autoConverted = false;
+				bool cascade = true;
+				CreateCitusLocalTable(relationId, cascade, autoConverted);
+			}
 		}
 
 		UtilityHookLevel--;
@@ -843,6 +866,50 @@ ShouldCheckUndistributeCitusLocalTables(void)
 }
 
 
+/*
+ * ShouldAddNewTableToMetadata takes a Node* and returns true if we need to add a
+ * newly created table to metadata, false otherwise.
+ * This function checks whether the given Node* is a CREATE TABLE statement.
+ * For partitions and temporary tables, ShouldAddNewTableToMetadata returns false.
+ * For other tables created, returns true, if we are on a coordinator that is added
+ * as worker, and ofcourse, if the GUC use_citus_managed_tables is set to on.
+ */
+static bool
+ShouldAddNewTableToMetadata(Node *parsetree)
+{
+	if (!IsA(parsetree, CreateStmt))
+	{
+		/* if the command is not CREATE TABLE, we can early return false */
+		return false;
+	}
+
+	CreateStmt *createTableStmt = (CreateStmt *) parsetree;
+
+	if (createTableStmt->relation->relpersistence == RELPERSISTENCE_TEMP ||
+		createTableStmt->partbound != NULL)
+	{
+		/*
+		 * Shouldn't add table to metadata if it's a temp table, or a partition.
+		 * Creating partitions of a table that is added to metadata is already handled.
+		 */
+		return false;
+	}
+
+	if (AddAllLocalTablesToMetadata && !IsBinaryUpgrade &&
+		IsCoordinator() && CoordinatorAddedAsWorkerNode())
+	{
+		/*
+		 * We have verified that the GUC is set to true, and we are not upgrading,
+		 * and we are on the coordinator that is added as worker node.
+		 * So return true here, to add this newly created table to metadata.
+		 */
+		return true;
+	}
+
+	return false;
+}
+
+
 /*
  * NotifyUtilityHookConstraintDropped sets ConstraintDropped to true to tell us
  * last command dropped a table constraint.

src/backend/distributed/shared_library_init.c

@@ -1671,6 +1671,17 @@ RegisterCitusConfigVariables(void)
 		GUC_STANDARD,
 		WarnIfDeprecatedExecutorUsed, NULL, NULL);
 
+	DefineCustomBoolVariable(
+		"citus.use_citus_managed_tables",
+		gettext_noop("Allows new local tables to be accessed on workers"),
+		gettext_noop("Adds all newly created tables to Citus metadata by default, "
+					 "when enabled. Set to false by default."),
+		&AddAllLocalTablesToMetadata,
+		false,
+		PGC_USERSET,
+		GUC_STANDARD,
+		NULL, NULL, NULL);
+
 	DefineCustomEnumVariable(
 		"citus.use_secondary_nodes",
 		gettext_noop("Sets the policy to use when choosing nodes for SELECT queries."),

src/include/distributed/commands.h

@@ -21,6 +21,8 @@
 #include "tcop/utility.h"
 
 
+extern bool AddAllLocalTablesToMetadata;
+
 /* controlled via GUC, should be accessed via EnableLocalReferenceForeignKeys() */
 extern bool EnableLocalReferenceForeignKeys;
 

src/test/regress/expected/auto_undist_citus_local.out

@@ -450,22 +450,13 @@ SELECT logicalrelid, partmethod, repmodel FROM pg_dist_partition WHERE logicalre
 
 -- verify that citus local tables converted by the user will not be auto-undistributed
 DROP TABLE IF EXISTS citus_local_table_1, citus_local_table_2, citus_local_table_3;
+-- this GUC will add the next three tables to metadata automatically
+SET citus.use_citus_managed_tables TO ON;
 CREATE TABLE citus_local_table_1(a INT UNIQUE);
 CREATE TABLE citus_local_table_2(a INT UNIQUE);
 CREATE TABLE citus_local_table_3(a INT UNIQUE);
+RESET citus.use_citus_managed_tables;
 ALTER TABLE citus_local_table_1 ADD CONSTRAINT fkey_cas_test FOREIGN KEY (a) REFERENCES citus_local_table_2 (a);
-SELECT citus_add_local_table_to_metadata('citus_local_table_1', cascade_via_foreign_keys=>true);
- citus_add_local_table_to_metadata
----------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_add_local_table_to_metadata('citus_local_table_3');
- citus_add_local_table_to_metadata
----------------------------------------------------------------------
-
-(1 row)
-
 ALTER TABLE citus_local_table_3 ADD CONSTRAINT fkey_cas_test_2 FOREIGN KEY (a) REFERENCES citus_local_table_2 (a);
 ALTER TABLE citus_local_table_3 DROP CONSTRAINT fkey_cas_test_2;
 SELECT logicalrelid, autoconverted FROM pg_dist_partition

src/test/regress/expected/citus_local_tables.out

@@ -724,20 +724,12 @@ FROM (SELECT tableName FROM pg_catalog.pg_tables WHERE tablename LIKE 'citus_loc
 -- cannot create a citus local table from a catalog table
 SELECT citus_add_local_table_to_metadata('pg_class');
 ERROR:  cannot create a citus table from a catalog table
+-- testing foreign key connection between citus local tables,
+-- using the GUC use_citus_managed_tables to add tables to metadata
+SET citus.use_citus_managed_tables TO ON;
 CREATE TABLE referencing_table(a int);
-SELECT citus_add_local_table_to_metadata('referencing_table');
- citus_add_local_table_to_metadata
----------------------------------------------------------------------
-
-(1 row)
-
 CREATE TABLE referenced_table(a int UNIQUE);
-SELECT citus_add_local_table_to_metadata('referenced_table');
- citus_add_local_table_to_metadata
----------------------------------------------------------------------
-
-(1 row)
-
+RESET citus.use_citus_managed_tables;
 ALTER TABLE referencing_table ADD CONSTRAINT fkey_cl_to_cl FOREIGN KEY (a) REFERENCES referenced_table(a);
 NOTICE:  executing the command locally: SELECT worker_apply_inter_shard_ddl_command (xxxxx, 'citus_local_tables_test_schema', xxxxx, 'citus_local_tables_test_schema', 'ALTER TABLE referencing_table ADD CONSTRAINT fkey_cl_to_cl FOREIGN KEY (a) REFERENCES referenced_table(a);')
 -- verify creating citus local table with extended statistics

src/test/regress/sql/auto_undist_citus_local.sql

@@ -210,12 +210,14 @@ SELECT logicalrelid, partmethod, repmodel FROM pg_dist_partition WHERE logicalre
 
 -- verify that citus local tables converted by the user will not be auto-undistributed
 DROP TABLE IF EXISTS citus_local_table_1, citus_local_table_2, citus_local_table_3;
+
+-- this GUC will add the next three tables to metadata automatically
+SET citus.use_citus_managed_tables TO ON;
 CREATE TABLE citus_local_table_1(a INT UNIQUE);
 CREATE TABLE citus_local_table_2(a INT UNIQUE);
 CREATE TABLE citus_local_table_3(a INT UNIQUE);
+RESET citus.use_citus_managed_tables;
 ALTER TABLE citus_local_table_1 ADD CONSTRAINT fkey_cas_test FOREIGN KEY (a) REFERENCES citus_local_table_2 (a);
-SELECT citus_add_local_table_to_metadata('citus_local_table_1', cascade_via_foreign_keys=>true);
-SELECT citus_add_local_table_to_metadata('citus_local_table_3');
 ALTER TABLE citus_local_table_3 ADD CONSTRAINT fkey_cas_test_2 FOREIGN KEY (a) REFERENCES citus_local_table_2 (a);
 ALTER TABLE citus_local_table_3 DROP CONSTRAINT fkey_cas_test_2;
 SELECT logicalrelid, autoconverted FROM pg_dist_partition

src/test/regress/sql/citus_local_tables.sql

@@ -471,11 +471,12 @@ FROM (SELECT tableName FROM pg_catalog.pg_tables WHERE tablename LIKE 'citus_loc
 -- cannot create a citus local table from a catalog table
 SELECT citus_add_local_table_to_metadata('pg_class');
 
+-- testing foreign key connection between citus local tables,
+-- using the GUC use_citus_managed_tables to add tables to metadata
+SET citus.use_citus_managed_tables TO ON;
 CREATE TABLE referencing_table(a int);
-SELECT citus_add_local_table_to_metadata('referencing_table');
-
 CREATE TABLE referenced_table(a int UNIQUE);
-SELECT citus_add_local_table_to_metadata('referenced_table');
+RESET citus.use_citus_managed_tables;
 
 ALTER TABLE referencing_table ADD CONSTRAINT fkey_cl_to_cl FOREIGN KEY (a) REFERENCES referenced_table(a);