Merge pull request #4479 from citusdata/alter-table-add-fkey

Convert postgres tables to citus local tables for ALTER TABLE commands defining foreign keys

src/backend/distributed/commands/cascade_table_operation_for_connected_relations.c

@@ -369,7 +369,19 @@ ExecuteCascadeOperationForRelationIdList(List *relationIdList,
 
 			case CASCADE_FKEY_CREATE_CITUS_LOCAL_TABLE:
 			{
-				CreateCitusLocalTable(relationId, cascadeViaForeignKeys);
+				if (!IsCitusTable(relationId))
+				{
+					/*
+					 * Normally, we wouldn't expect a postgres table connected
+					 * to a citus local table via a foreign keys graph. But now
+					 * this is possible as we allow foreign keys from postgres
+					 * tables to reference tables when coordinator is not added
+					 * to metadata. So instead of erroring out, we skip citus
+					 * tables here.
+					 */
+					CreateCitusLocalTable(relationId, cascadeViaForeignKeys);
+				}
+
 				break;
 			}
 

src/backend/distributed/commands/cluster.c

@@ -17,7 +17,8 @@
 
 /* placeholder for PreprocessClusterStmt */
 List *
-PreprocessClusterStmt(Node *node, const char *clusterCommand)
+PreprocessClusterStmt(Node *node, const char *clusterCommand,
+					  ProcessUtilityContext processUtilityContext)
 {
 	ClusterStmt *clusterStmt = castNode(ClusterStmt, node);
 	bool showPropagationWarning = false;

src/backend/distributed/commands/collation.c

@@ -220,7 +220,8 @@ FilterNameListForDistributedCollations(List *objects, bool missing_ok,
 
 
 List *
-PreprocessDropCollationStmt(Node *node, const char *queryString)
+PreprocessDropCollationStmt(Node *node, const char *queryString,
+							ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *stmt = castNode(DropStmt, node);
 
@@ -290,7 +291,8 @@ PreprocessDropCollationStmt(Node *node, const char *queryString)
  * the workers to keep the type in sync across the cluster.
  */
 List *
-PreprocessAlterCollationOwnerStmt(Node *node, const char *queryString)
+PreprocessAlterCollationOwnerStmt(Node *node, const char *queryString,
+								  ProcessUtilityContext processUtilityContext)
 {
 	AlterOwnerStmt *stmt = castNode(AlterOwnerStmt, node);
 	Assert(stmt->objectType == OBJECT_COLLATION);
@@ -324,7 +326,8 @@ PreprocessAlterCollationOwnerStmt(Node *node, const char *queryString)
  * executed on all the workers to keep the collation in sync across the cluster.
  */
 List *
-PreprocessRenameCollationStmt(Node *node, const char *queryString)
+PreprocessRenameCollationStmt(Node *node, const char *queryString,
+							  ProcessUtilityContext processUtilityContext)
 {
 	RenameStmt *stmt = castNode(RenameStmt, node);
 	ObjectAddress collationAddress = GetObjectAddressFromParseTree((Node *) stmt, false);
@@ -357,7 +360,8 @@ PreprocessRenameCollationStmt(Node *node, const char *queryString)
  * In this stage we can prepare the commands that need to be run on all workers.
  */
 List *
-PreprocessAlterCollationSchemaStmt(Node *node, const char *queryString)
+PreprocessAlterCollationSchemaStmt(Node *node, const char *queryString,
+								   ProcessUtilityContext processUtilityContext)
 {
 	AlterObjectSchemaStmt *stmt = castNode(AlterObjectSchemaStmt, node);
 	Assert(stmt->objectType == OBJECT_COLLATION);

src/backend/distributed/commands/extension.c

@@ -239,7 +239,8 @@ AddSchemaFieldIfMissing(CreateExtensionStmt *createExtensionStmt)
  * be made to the workers.
  */
 List *
-PreprocessDropExtensionStmt(Node *node, const char *queryString)
+PreprocessDropExtensionStmt(Node *node, const char *queryString,
+							ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *stmt = castNode(DropStmt, node);
 
@@ -386,7 +387,8 @@ ExtensionNameListToObjectAddressList(List *extensionObjectList)
  * PreprocessAlterExtensionSchemaStmt is invoked for alter extension set schema statements.
  */
 List *
-PreprocessAlterExtensionSchemaStmt(Node *node, const char *queryString)
+PreprocessAlterExtensionSchemaStmt(Node *node, const char *queryString,
+								   ProcessUtilityContext processUtilityContext)
 {
 	if (!ShouldPropagateExtensionCommand(node))
 	{
@@ -451,7 +453,8 @@ PostprocessAlterExtensionSchemaStmt(Node *node, const char *queryString)
  * PreprocessAlterExtensionUpdateStmt is invoked for alter extension update statements.
  */
 List *
-PreprocessAlterExtensionUpdateStmt(Node *node, const char *queryString)
+PreprocessAlterExtensionUpdateStmt(Node *node, const char *queryString,
+								   ProcessUtilityContext processUtilityContext)
 {
 	AlterExtensionStmt *alterExtensionStmt = castNode(AlterExtensionStmt, node);
 
@@ -599,7 +602,8 @@ MarkExistingObjectDependenciesDistributedIfSupported()
  * PreprocessAlterExtensionContentsStmt issues a notice. It does not propagate.
  */
 List *
-PreprocessAlterExtensionContentsStmt(Node *node, const char *queryString)
+PreprocessAlterExtensionContentsStmt(Node *node, const char *queryString,
+									 ProcessUtilityContext processUtilityContext)
 {
 	ereport(NOTICE, (errmsg(
 						 "Citus does not propagate adding/dropping member objects"),

src/backend/distributed/commands/function.c

@@ -1244,7 +1244,8 @@ ShouldPropagateAlterFunction(const ObjectAddress *address)
  * can propagate the function in sequential mode.
  */
 List *
-PreprocessCreateFunctionStmt(Node *node, const char *queryString)
+PreprocessCreateFunctionStmt(Node *node, const char *queryString,
+							 ProcessUtilityContext processUtilityContext)
 {
 	CreateFunctionStmt *stmt = castNode(CreateFunctionStmt, node);
 
@@ -1356,7 +1357,8 @@ DefineAggregateStmtObjectAddress(Node *node, bool missing_ok)
  * the cluster.
  */
 List *
-PreprocessAlterFunctionStmt(Node *node, const char *queryString)
+PreprocessAlterFunctionStmt(Node *node, const char *queryString,
+							ProcessUtilityContext processUtilityContext)
 {
 	AlterFunctionStmt *stmt = castNode(AlterFunctionStmt, node);
 	AssertObjectTypeIsFunctional(stmt->objtype);
@@ -1390,7 +1392,8 @@ PreprocessAlterFunctionStmt(Node *node, const char *queryString)
  * types in sync across the cluster.
  */
 List *
-PreprocessRenameFunctionStmt(Node *node, const char *queryString)
+PreprocessRenameFunctionStmt(Node *node, const char *queryString,
+							 ProcessUtilityContext processUtilityContext)
 {
 	RenameStmt *stmt = castNode(RenameStmt, node);
 	AssertObjectTypeIsFunctional(stmt->renameType);
@@ -1421,7 +1424,8 @@ PreprocessRenameFunctionStmt(Node *node, const char *queryString)
  * In this stage we can prepare the commands that need to be run on all workers.
  */
 List *
-PreprocessAlterFunctionSchemaStmt(Node *node, const char *queryString)
+PreprocessAlterFunctionSchemaStmt(Node *node, const char *queryString,
+								  ProcessUtilityContext processUtilityContext)
 {
 	AlterObjectSchemaStmt *stmt = castNode(AlterObjectSchemaStmt, node);
 	AssertObjectTypeIsFunctional(stmt->objectType);
@@ -1453,7 +1457,8 @@ PreprocessAlterFunctionSchemaStmt(Node *node, const char *queryString)
  * all the workers to keep the type in sync across the cluster.
  */
 List *
-PreprocessAlterFunctionOwnerStmt(Node *node, const char *queryString)
+PreprocessAlterFunctionOwnerStmt(Node *node, const char *queryString,
+								 ProcessUtilityContext processUtilityContext)
 {
 	AlterOwnerStmt *stmt = castNode(AlterOwnerStmt, node);
 	AssertObjectTypeIsFunctional(stmt->objectType);
@@ -1487,7 +1492,8 @@ PreprocessAlterFunctionOwnerStmt(Node *node, const char *queryString)
  * functions will still be dropped locally but not on the workers.
  */
 List *
-PreprocessDropFunctionStmt(Node *node, const char *queryString)
+PreprocessDropFunctionStmt(Node *node, const char *queryString,
+						   ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *stmt = castNode(DropStmt, node);
 	List *deletingObjectWithArgsList = stmt->objects;
@@ -1591,7 +1597,8 @@ PreprocessDropFunctionStmt(Node *node, const char *queryString)
  * don't allow this dependency to be created.
  */
 List *
-PreprocessAlterFunctionDependsStmt(Node *node, const char *queryString)
+PreprocessAlterFunctionDependsStmt(Node *node, const char *queryString,
+								   ProcessUtilityContext processUtilityContext)
 {
 	AlterObjectDependsStmt *stmt = castNode(AlterObjectDependsStmt, node);
 	AssertObjectTypeIsFunctional(stmt->objectType);

src/backend/distributed/commands/grant.c

@@ -13,7 +13,8 @@
 
 /* placeholder for PreprocessGrantStmt */
 List *
-PreprocessGrantStmt(Node *node, const char *queryString)
+PreprocessGrantStmt(Node *node, const char *queryString,
+					ProcessUtilityContext processUtilityContext)
 {
 	return NIL;
 }

src/backend/distributed/commands/index.c

@@ -130,7 +130,8 @@ IsIndexRenameStmt(RenameStmt *renameStmt)
  * in a List. If no distributed table is involved, this function returns NIL.
  */
 List *
-PreprocessIndexStmt(Node *node, const char *createIndexCommand)
+PreprocessIndexStmt(Node *node, const char *createIndexCommand,
+					ProcessUtilityContext processUtilityContext)
 {
 	IndexStmt *createIndexStatement = castNode(IndexStmt, node);
 
@@ -528,7 +529,8 @@ GetCreateIndexRelationLockMode(IndexStmt *createIndexStatement)
  * in a List. If no distributed table is involved, this function returns NIL.
  */
 List *
-PreprocessReindexStmt(Node *node, const char *reindexCommand)
+PreprocessReindexStmt(Node *node, const char *reindexCommand,
+					  ProcessUtilityContext processUtilityContext)
 {
 	ReindexStmt *reindexStatement = castNode(ReindexStmt, node);
 	List *ddlJobs = NIL;
@@ -637,7 +639,8 @@ PreprocessReindexStmt(Node *node, const char *reindexCommand)
  * in a List. If no distributed table is involved, this function returns NIL.
  */
 List *
-PreprocessDropIndexStmt(Node *node, const char *dropIndexCommand)
+PreprocessDropIndexStmt(Node *node, const char *dropIndexCommand,
+						ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *dropIndexStatement = castNode(DropStmt, node);
 	List *ddlJobs = NIL;

src/backend/distributed/commands/policy.c

@@ -28,7 +28,8 @@ CreatePolicyCommands(Oid relationId)
 
 /* placeholder for PreprocessCreatePolicyStmt */
 List *
-PreprocessCreatePolicyStmt(Node *node, const char *queryString)
+PreprocessCreatePolicyStmt(Node *node, const char *queryString,
+						   ProcessUtilityContext processUtilityContext)
 {
 	CreatePolicyStmt *stmt = castNode(CreatePolicyStmt, node);
 	Oid relationId = RangeVarGetRelid(stmt->table,
@@ -48,7 +49,8 @@ PreprocessCreatePolicyStmt(Node *node, const char *queryString)
 
 /* placeholder for PreprocessAlterPolicyStmt */
 List *
-PreprocessAlterPolicyStmt(Node *node, const char *queryString)
+PreprocessAlterPolicyStmt(Node *node, const char *queryString,
+						  ProcessUtilityContext processUtilityContext)
 {
 	/* placeholder for future implementation */
 	return NIL;
@@ -71,7 +73,8 @@ ErrorIfUnsupportedPolicy(Relation relation)
 
 /* placeholder for PreprocessDropPolicyStmt */
 List *
-PreprocessDropPolicyStmt(Node *node, const char *queryString)
+PreprocessDropPolicyStmt(Node *node, const char *queryString,
+						 ProcessUtilityContext processUtilityContext)
 {
 	/* placeholder for future implementation */
 	return NIL;

src/backend/distributed/commands/rename.c

@@ -26,7 +26,8 @@
  * tributed table is involved, this function returns NIL.
  */
 List *
-PreprocessRenameStmt(Node *node, const char *renameCommand)
+PreprocessRenameStmt(Node *node, const char *renameCommand,
+					 ProcessUtilityContext processUtilityContext)
 {
 	RenameStmt *renameStmt = castNode(RenameStmt, node);
 	Oid objectRelationId = InvalidOid; /* SQL Object OID */
@@ -144,7 +145,8 @@ ErrorIfUnsupportedRenameStmt(RenameStmt *renameStmt)
  * a specialized implementation if present, otherwise return an empty list for its DDLJobs
  */
 List *
-PreprocessRenameAttributeStmt(Node *node, const char *queryString)
+PreprocessRenameAttributeStmt(Node *node, const char *queryString,
+							  ProcessUtilityContext processUtilityContext)
 {
 	RenameStmt *stmt = castNode(RenameStmt, node);
 	Assert(stmt->renameType == OBJECT_ATTRIBUTE);
@@ -153,7 +155,8 @@ PreprocessRenameAttributeStmt(Node *node, const char *queryString)
 	{
 		case OBJECT_TYPE:
 		{
-			return PreprocessRenameTypeAttributeStmt(node, queryString);
+			return PreprocessRenameTypeAttributeStmt(node, queryString,
+													 processUtilityContext);
 		}
 
 		default:

src/backend/distributed/commands/role.c

@@ -181,7 +181,8 @@ PostprocessAlterRoleStmt(Node *node, const char *queryString)
  * role set statement.
  */
 List *
-PreprocessAlterRoleSetStmt(Node *node, const char *queryString)
+PreprocessAlterRoleSetStmt(Node *node, const char *queryString,
+						   ProcessUtilityContext processUtilityContext)
 {
 	if (!ShouldPropagate())
 	{

src/backend/distributed/commands/schema.c

@@ -49,7 +49,8 @@ static void EnsureSequentialModeForSchemaDDL(void);
  * under dropped schema involved in any foreign key relationship.
  */
 List *
-PreprocessDropSchemaStmt(Node *node, const char *queryString)
+PreprocessDropSchemaStmt(Node *node, const char *queryString,
+						 ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *dropStatement = castNode(DropStmt, node);
 	Relation pgClass = NULL;
@@ -133,7 +134,8 @@ PreprocessDropSchemaStmt(Node *node, const char *queryString)
  * on schemas. Only grant statements for distributed schema are propagated.
  */
 List *
-PreprocessGrantOnSchemaStmt(Node *node, const char *queryString)
+PreprocessGrantOnSchemaStmt(Node *node, const char *queryString,
+							ProcessUtilityContext processUtilityContext)
 {
 	GrantStmt *stmt = castNode(GrantStmt, node);
 	Assert(stmt->objtype == OBJECT_SCHEMA);
@@ -166,7 +168,8 @@ PreprocessGrantOnSchemaStmt(Node *node, const char *queryString)
  * is executed on all the workers to keep the schemas in sync across the cluster.
  */
 List *
-PreprocessAlterSchemaRenameStmt(Node *node, const char *queryString)
+PreprocessAlterSchemaRenameStmt(Node *node, const char *queryString,
+								ProcessUtilityContext processUtilityContext)
 {
 	ObjectAddress schemaAddress = GetObjectAddressFromParseTree(node, false);
 	if (!ShouldPropagateObject(&schemaAddress))

src/backend/distributed/commands/statistics.c

@@ -65,7 +65,8 @@ static char * CreateAlterCommandIfTargetNotDefault(Oid statsOid);
  * CREATE STATISTICS.
  */
 List *
-PreprocessCreateStatisticsStmt(Node *node, const char *queryString)
+PreprocessCreateStatisticsStmt(Node *node, const char *queryString,
+							   ProcessUtilityContext processUtilityContext)
 {
 	CreateStatsStmt *stmt = castNode(CreateStatsStmt, node);
 
@@ -150,7 +151,8 @@ CreateStatisticsStmtObjectAddress(Node *node, bool missingOk)
  * DROP STATISTICS.
  */
 List *
-PreprocessDropStatisticsStmt(Node *node, const char *queryString)
+PreprocessDropStatisticsStmt(Node *node, const char *queryString,
+							 ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *dropStatisticsStmt = castNode(DropStmt, node);
 	Assert(dropStatisticsStmt->removeType == OBJECT_STATISTIC_EXT);
@@ -208,7 +210,8 @@ PreprocessDropStatisticsStmt(Node *node, const char *queryString)
  * ALTER STATISTICS RENAME.
  */
 List *
-PreprocessAlterStatisticsRenameStmt(Node *node, const char *queryString)
+PreprocessAlterStatisticsRenameStmt(Node *node, const char *queryString,
+									ProcessUtilityContext processUtilityContext)
 {
 	RenameStmt *renameStmt = castNode(RenameStmt, node);
 	Assert(renameStmt->renameType == OBJECT_STATISTIC_EXT);
@@ -246,7 +249,8 @@ PreprocessAlterStatisticsRenameStmt(Node *node, const char *queryString)
  * ALTER STATISTICS SET SCHEMA.
  */
 List *
-PreprocessAlterStatisticsSchemaStmt(Node *node, const char *queryString)
+PreprocessAlterStatisticsSchemaStmt(Node *node, const char *queryString,
+									ProcessUtilityContext processUtilityContext)
 {
 	AlterObjectSchemaStmt *stmt = castNode(AlterObjectSchemaStmt, node);
 	Assert(stmt->objectType == OBJECT_STATISTIC_EXT);
@@ -338,7 +342,8 @@ AlterStatisticsSchemaStmtObjectAddress(Node *node, bool missingOk)
  * ALTER STATISTICS .. SET STATISTICS.
  */
 List *
-PreprocessAlterStatisticsStmt(Node *node, const char *queryString)
+PreprocessAlterStatisticsStmt(Node *node, const char *queryString,
+							  ProcessUtilityContext processUtilityContext)
 {
 	AlterStatsStmt *stmt = castNode(AlterStatsStmt, node);
 
@@ -377,7 +382,8 @@ PreprocessAlterStatisticsStmt(Node *node, const char *queryString)
  * ALTER STATISTICS .. OWNER TO.
  */
 List *
-PreprocessAlterStatisticsOwnerStmt(Node *node, const char *queryString)
+PreprocessAlterStatisticsOwnerStmt(Node *node, const char *queryString,
+								   ProcessUtilityContext processUtilityContext)
 {
 	AlterOwnerStmt *stmt = castNode(AlterOwnerStmt, node);
 	Assert(stmt->objectType == OBJECT_STATISTIC_EXT);

src/backend/distributed/commands/table.c

@@ -45,10 +45,23 @@
 /* Local functions forward declarations for unsupported command checks */
 static void PostprocessCreateTableStmtPartitionOf(CreateStmt *createStatement,
 												  const char *queryString);
-static void ErrorIfAlterTableDefinesFKeyFromPostgresToCitusLocalTable(
+static bool AlterTableDefinesFKeyBetweenPostgresAndNonDistTable(
 	AlterTableStmt *alterTableStatement);
-static List * GetAlterTableStmtFKeyConstraintList(AlterTableStmt *alterTableStatement);
+static bool RelationIdListContainsCitusTableType(List *relationIdList,
+												 CitusTableType citusTableType);
+static bool RelationIdListContainsPostgresTable(List *relationIdList);
+static void ConvertPostgresLocalTablesToCitusLocalTables(
+	AlterTableStmt *alterTableStatement);
+static int CompareRangeVarsByOid(const void *leftElement, const void *rightElement);
+static List * GetAlterTableAddFKeyRightRelationIdList(
+	AlterTableStmt *alterTableStatement);
+static List * GetAlterTableAddFKeyRightRelationRangeVarList(
+	AlterTableStmt *alterTableStatement);
+static List * GetAlterTableAddFKeyConstraintList(AlterTableStmt *alterTableStatement);
 static List * GetAlterTableCommandFKeyConstraintList(AlterTableCmd *command);
+static List * GetRangeVarListFromFKeyConstraintList(List *fKeyConstraintList);
+static List * GetRelationIdListFromRangeVarList(List *rangeVarList, LOCKMODE lockmode,
+												bool missingOk);
 static bool AlterTableCommandTypeIsTrigger(AlterTableType alterTableType);
 static void ErrorIfUnsupportedAlterTableStmt(AlterTableStmt *alterTableStatement);
 static void ErrorIfCitusLocalTablePartitionCommand(AlterTableCmd *alterTableCmd,
@@ -87,7 +100,8 @@ static bool SetupExecutionModeForAlterTable(Oid relationId, AlterTableCmd *comma
  * about not processing same DROP command twice.
  */
 List *
-PreprocessDropTableStmt(Node *node, const char *queryString)
+PreprocessDropTableStmt(Node *node, const char *queryString,
+						ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *dropTableStatement = castNode(DropStmt, node);
 
@@ -153,7 +167,7 @@ PreprocessDropTableStmt(Node *node, const char *queryString)
 /*
  * PostprocessCreateTableStmt takes CreateStmt object as a parameter and errors
  * out if it creates a table with a foreign key that references to a citus local
- * table if pg version is older than 13 (see comment in function).
+ * table.
  *
  * This function also processes CREATE TABLE ... PARTITION OF statements via
  * PostprocessCreateTableStmtPartitionOf function.
@@ -161,17 +175,6 @@ PreprocessDropTableStmt(Node *node, const char *queryString)
 void
 PostprocessCreateTableStmt(CreateStmt *createStatement, const char *queryString)
 {
-#if PG_VERSION_NUM < PG_VERSION_13
-
-	/*
-	 * Postgres processes foreign key constraints implied by CREATE TABLE
-	 * commands by internally executing ALTER TABLE commands via standard
-	 * process utility starting from PG13. Hence, we will already perform
-	 * unsupported foreign key checks via PreprocessAlterTableStmt function
-	 * in PG13. But for the older version, we need to do unsupported foreign
-	 * key checks here.
-	 */
-
 	/*
 	 * Relation must exist and it is already locked as standard process utility
 	 * is already executed.
@@ -182,7 +185,6 @@ PostprocessCreateTableStmt(CreateStmt *createStatement, const char *queryString)
 	{
 		ErrorOutForFKeyBetweenPostgresAndCitusLocalTable(relationId);
 	}
-#endif
 
 	if (createStatement->inhRelations != NIL && createStatement->partbound != NULL)
 	{
@@ -346,7 +348,8 @@ PostprocessAlterTableSchemaStmt(Node *node, const char *queryString)
  * function returns NIL.
  */
 List *
-PreprocessAlterTableStmt(Node *node, const char *alterTableCommand)
+PreprocessAlterTableStmt(Node *node, const char *alterTableCommand,
+						 ProcessUtilityContext processUtilityContext)
 {
 	AlterTableStmt *alterTableStatement = castNode(AlterTableStmt, node);
 
@@ -376,14 +379,38 @@ PreprocessAlterTableStmt(Node *node, const char *alterTableCommand)
 		leftRelationId = IndexGetRelation(leftRelationId, missingOk);
 	}
 
-	/*
+	if (processUtilityContext != PROCESS_UTILITY_SUBCOMMAND &&
-	 * Normally, we would do this check in ErrorIfUnsupportedForeignConstraintExists
+		AlterTableDefinesFKeyBetweenPostgresAndNonDistTable(alterTableStatement) &&
-	 * in post process step. However, we skip doing error checks in post process if
+		CoordinatorAddedAsWorkerNode())
-	 * this pre process returns NIL -and this method returns NIL if the left relation
+	{
-	 * is a postgres table. So, we need to error out for foreign keys from postgres
+		/*
-	 * tables to citus local tables here.
+		 * We don't process subcommands generated by postgres.
-	 */
+		 * This is mainly because postgres started to issue ALTER TABLE commands
-	ErrorIfAlterTableDefinesFKeyFromPostgresToCitusLocalTable(alterTableStatement);
+		 * for some set of objects that are defined via CREATE TABLE commands as
+		 * of pg13. However, citus already has a separate logic for CREATE TABLE
+		 * commands.
+		 *
+		 * To support foreign keys from/to postgres local tables to/from reference
+		 * or citus local tables, we convert given postgres local table -and the
+		 * other postgres tables that it is connected via a fkey graph- to a citus
+		 * local table.
+		 *
+		 * Note that we don't convert postgres tables to citus local tables if
+		 * coordinator is not added to metadata as CreateCitusLocalTable requires
+		 * this. In this case, we assume user is about to create reference or
+		 * distributed table from local table and we don't want to break user
+		 * experience by asking to add coordinator to metadata.
+		 */
+		ConvertPostgresLocalTablesToCitusLocalTables(alterTableStatement);
+
+		/*
+		 * CreateCitusLocalTable converts relation to a shard relation and creates
+		 * shell table from scratch.
+		 * For this reason we should re-enter to PreprocessAlterTableStmt to operate
+		 * on shell table relation id.
+		 */
+		return PreprocessAlterTableStmt(node, alterTableCommand, processUtilityContext);
+	}
 
 	bool referencingIsLocalTable = !IsCitusTable(leftRelationId);
 	if (referencingIsLocalTable)
@@ -593,59 +620,249 @@ PreprocessAlterTableStmt(Node *node, const char *alterTableCommand)
 
 
 /*
- * ErrorIfAlterTableDefinesFKeyFromPostgresToCitusLocalTable errors out if
+ * AlterTableDefinesFKeyBetweenPostgresAndNonDistTable returns true if given
- * given ALTER TABLE statement defines foreign key from a postgres local table
+ * alter table command defines foreign key between a postgres table and a
- * to a citus local table.
+ * reference or citus local table.
  */
-static void
+static bool
-ErrorIfAlterTableDefinesFKeyFromPostgresToCitusLocalTable(
+AlterTableDefinesFKeyBetweenPostgresAndNonDistTable(AlterTableStmt *alterTableStatement)
-	AlterTableStmt *alterTableStatement)
 {
-	List *commandList = alterTableStatement->cmds;
+	List *foreignKeyConstraintList =
-
+		GetAlterTableAddFKeyConstraintList(alterTableStatement);
-	LOCKMODE lockmode = AlterTableGetLockLevel(commandList);
+	if (list_length(foreignKeyConstraintList) == 0)
-	Oid leftRelationId = AlterTableLookupRelation(alterTableStatement, lockmode);
-
-	if (IsCitusTable(leftRelationId))
 	{
-		/* left relation is not a postgres local table, */
+		/* we are not defining any foreign keys */
-		return;
+		return false;
 	}
 
-	List *alterTableFKeyConstraints =
+	List *rightRelationIdList =
-		GetAlterTableStmtFKeyConstraintList(alterTableStatement);
+		GetAlterTableAddFKeyRightRelationIdList(alterTableStatement);
-	Constraint *constraint = NULL;
+
-	foreach_ptr(constraint, alterTableFKeyConstraints)
+	LOCKMODE lockmode = AlterTableGetLockLevel(alterTableStatement->cmds);
+	Oid leftRelationId = AlterTableLookupRelation(alterTableStatement, lockmode);
+	if (!IsCitusTable(leftRelationId))
 	{
-		Oid rightRelationId = RangeVarGetRelid(constraint->pktable, lockmode,
+		return RelationIdListContainsCitusTableType(rightRelationIdList,
-											   alterTableStatement->missing_ok);
+													CITUS_TABLE_WITH_NO_DIST_KEY);
-		if (IsCitusTableType(rightRelationId, CITUS_LOCAL_TABLE))
+	}
+	else if (IsCitusTableType(leftRelationId, CITUS_TABLE_WITH_NO_DIST_KEY))
+	{
+		return RelationIdListContainsPostgresTable(rightRelationIdList);
+	}
+
+	return false;
+}
+
+
+/*
+ * RelationIdListContainsCitusTableType returns true if given relationIdList
+ * contains a citus table with given type.
+ */
+static bool
+RelationIdListContainsCitusTableType(List *relationIdList, CitusTableType citusTableType)
+{
+	Oid relationId = InvalidOid;
+	foreach_oid(relationId, relationIdList)
+	{
+		if (IsCitusTableType(relationId, citusTableType))
 		{
-			ErrorOutForFKeyBetweenPostgresAndCitusLocalTable(leftRelationId);
+			return true;
 		}
 	}
+
+	return false;
+}
+
+
+/*
+ * RelationIdListContainsPostgresTable returns true if given relationIdList
+ * contains a postgres table.
+ */
+static bool
+RelationIdListContainsPostgresTable(List *relationIdList)
+{
+	Oid relationId = InvalidOid;
+	foreach_oid(relationId, relationIdList)
+	{
+		if (OidIsValid(relationId) && !IsCitusTable(relationId))
+		{
+			return true;
+		}
+	}
+
+	return false;
+}
+
+
+/*
+ * ConvertPostgresLocalTablesToCitusLocalTables converts each postgres table
+ * involved in foreign keys to be defined by given alter table command and the
+ * other tables connected to them via a foreign key graph to citus local tables.
+ */
+static void
+ConvertPostgresLocalTablesToCitusLocalTables(AlterTableStmt *alterTableStatement)
+{
+	List *rightRelationRangeVarList =
+		GetAlterTableAddFKeyRightRelationRangeVarList(alterTableStatement);
+	RangeVar *leftRelationRangeVar = alterTableStatement->relation;
+	List *relationRangeVarList = lappend(rightRelationRangeVarList, leftRelationRangeVar);
+
+	/*
+	 * To prevent deadlocks, sort the list before converting each postgres local
+	 * table to a citus local table.
+	 */
+	relationRangeVarList = SortList(relationRangeVarList, CompareRangeVarsByOid);
+
+	/*
+	 * Here we should operate on RangeVar objects since relations oid's would
+	 * change in below loop due to CreateCitusLocalTable.
+	 */
+	RangeVar *relationRangeVar;
+	foreach_ptr(relationRangeVar, relationRangeVarList)
+	{
+		List *commandList = alterTableStatement->cmds;
+		LOCKMODE lockMode = AlterTableGetLockLevel(commandList);
+		bool missingOk = alterTableStatement->missing_ok;
+		Oid relationId = RangeVarGetRelid(relationRangeVar, lockMode, missingOk);
+		if (!OidIsValid(relationId))
+		{
+			/*
+			 * As we are in preprocess, missingOk might be true and relation
+			 * might not exist.
+			 */
+			continue;
+		}
+		else if (IsCitusTable(relationId))
+		{
+			/*
+			 * relationRangeVarList has also reference and citus local tables
+			 * involved in this ADD FOREIGN KEY command. Moreover, even if
+			 * relationId was belonging to a postgres  local table initially,
+			 * we might had already converted it to a citus local table by cascading.
+			 */
+			continue;
+		}
+
+		/*
+		 * The only reason behind using a try/catch block here is giving a proper
+		 * error message. For example, when creating a citus local table we might
+		 * give an error telling that partitioned tables are not supported for
+		 * citus local table creation. But as a user it wouldn't make much sense
+		 * to see such an error. So here we extend error message to tell that we
+		 * actually ended up with this error when trying to define the foreign key.
+		 *
+		 * Also, as CopyErrorData() requires (CurrentMemoryContext != ErrorContext),
+		 * so we store CurrentMemoryContext here.
+		 */
+		MemoryContext savedMemoryContext = CurrentMemoryContext;
+		PG_TRY();
+		{
+			bool cascade = true;
+			CreateCitusLocalTable(relationId, cascade);
+		}
+		PG_CATCH();
+		{
+			MemoryContextSwitchTo(savedMemoryContext);
+
+			ErrorData *errorData = CopyErrorData();
+			FlushErrorState();
+
+			if (errorData->elevel != ERROR)
+			{
+				PG_RE_THROW();
+			}
+
+			/* override error detail */
+			errorData->detail = "When adding a foreign key from a local table to "
+								"a reference table, Citus applies a conversion to "
+								"all the local tables in the foreign key graph";
+			ThrowErrorData(errorData);
+		}
+		PG_END_TRY();
+	}
 }
 
 
 /*
- * GetAlterTableStmtFKeyConstraintList returns a list of Constraint objects for
+ * CompareRangeVarsByOid is a comparison function to sort RangeVar object list.
- * the foreign keys that given ALTER TABLE statement defines.
+ */
+static int
+CompareRangeVarsByOid(const void *leftElement, const void *rightElement)
+{
+	RangeVar *leftRangeVar = *((RangeVar **) leftElement);
+	RangeVar *rightRangeVar = *((RangeVar **) rightElement);
+
+	/*
+	 * Any way we will check their existence, so it's okay to map non-existing
+	 * relations to InvalidOid when sorting.
+	 */
+	bool missingOk = true;
+
+	/*
+	 * As this is an object comparator function, there is no way to understand
+	 * proper lock mode. So assume caller already locked relations.
+	 */
+	LOCKMODE lockMode = NoLock;
+
+	Oid leftRelationId = RangeVarGetRelid(leftRangeVar, lockMode, missingOk);
+	Oid rightRelationId = RangeVarGetRelid(rightRangeVar, lockMode, missingOk);
+	return CompareOids(&leftRelationId, &rightRelationId);
+}
+
+
+/*
+ * GetAlterTableAddFKeyRightRelationIdList returns a list of oid's for right
+ * relations involved in foreign keys to be defined by given ALTER TABLE command.
  */
 static List *
-GetAlterTableStmtFKeyConstraintList(AlterTableStmt *alterTableStatement)
+GetAlterTableAddFKeyRightRelationIdList(AlterTableStmt *alterTableStatement)
 {
-	List *alterTableFKeyConstraintList = NIL;
+	List *rightRelationRangeVarList =
+		GetAlterTableAddFKeyRightRelationRangeVarList(alterTableStatement);
+	List *commandList = alterTableStatement->cmds;
+	LOCKMODE lockMode = AlterTableGetLockLevel(commandList);
+	bool missingOk = alterTableStatement->missing_ok;
+	List *rightRelationIdList =
+		GetRelationIdListFromRangeVarList(rightRelationRangeVarList, lockMode, missingOk);
+	return rightRelationIdList;
+}
+
+
+/*
+ * GetAlterTableAddFKeyRightRelationRangeVarList returns a list of RangeVar
+ * objects for right relations involved in foreign keys to be defined by
+ * given ALTER TABLE command.
+ */
+static List *
+GetAlterTableAddFKeyRightRelationRangeVarList(AlterTableStmt *alterTableStatement)
+{
+	List *fKeyConstraintList = GetAlterTableAddFKeyConstraintList(alterTableStatement);
+	List *rightRelationRangeVarList =
+		GetRangeVarListFromFKeyConstraintList(fKeyConstraintList);
+	return rightRelationRangeVarList;
+}
+
+
+/*
+ * GetAlterTableAddFKeyConstraintList returns a list of Constraint objects for
+ * foreign keys that given ALTER TABLE to be defined by given ALTER TABLE command.
+ */
+static List *
+GetAlterTableAddFKeyConstraintList(AlterTableStmt *alterTableStatement)
+{
+	List *foreignKeyConstraintList = NIL;
 
 	List *commandList = alterTableStatement->cmds;
 	AlterTableCmd *command = NULL;
 	foreach_ptr(command, commandList)
 	{
-		List *commandFKeyConstraintList = GetAlterTableCommandFKeyConstraintList(command);
+		List *commandForeignKeyConstraintList =
-		alterTableFKeyConstraintList = list_concat(alterTableFKeyConstraintList,
+			GetAlterTableCommandFKeyConstraintList(command);
-												   commandFKeyConstraintList);
+		foreignKeyConstraintList = list_concat(foreignKeyConstraintList,
+											   commandForeignKeyConstraintList);
 	}
 
-	return alterTableFKeyConstraintList;
+	return foreignKeyConstraintList;
 }
 
 
@@ -690,6 +907,47 @@ GetAlterTableCommandFKeyConstraintList(AlterTableCmd *command)
 }
 
 
+/*
+ * GetRangeVarListFromFKeyConstraintList returns a list of RangeVar objects for
+ * right relations in fKeyConstraintList.
+ */
+static List *
+GetRangeVarListFromFKeyConstraintList(List *fKeyConstraintList)
+{
+	List *rightRelationRangeVarList = NIL;
+
+	Constraint *fKeyConstraint = NULL;
+	foreach_ptr(fKeyConstraint, fKeyConstraintList)
+	{
+		RangeVar *rightRelationRangeVar = fKeyConstraint->pktable;
+		rightRelationRangeVarList = lappend(rightRelationRangeVarList,
+											rightRelationRangeVar);
+	}
+
+	return rightRelationRangeVarList;
+}
+
+
+/*
+ * GetRelationIdListFromRangeVarList returns relation id list for relations
+ * identified by RangeVar objects in given list.
+ */
+static List *
+GetRelationIdListFromRangeVarList(List *rangeVarList, LOCKMODE lockMode, bool missingOk)
+{
+	List *relationIdList = NIL;
+
+	RangeVar *rangeVar = NULL;
+	foreach_ptr(rangeVar, rangeVarList)
+	{
+		Oid rightRelationId = RangeVarGetRelid(rangeVar, lockMode, missingOk);
+		relationIdList = lappend_oid(relationIdList, rightRelationId);
+	}
+
+	return relationIdList;
+}
+
+
 /*
  * AlterTableCommandTypeIsTrigger returns true if given alter table command type
  * is identifies an ALTER TABLE .. TRIGGER .. command.
@@ -724,7 +982,8 @@ AlterTableCommandTypeIsTrigger(AlterTableType alterTableType)
  * the distributed environment. We warn out here.
  */
 List *
-PreprocessAlterTableMoveAllStmt(Node *node, const char *queryString)
+PreprocessAlterTableMoveAllStmt(Node *node, const char *queryString,
+								ProcessUtilityContext processUtilityContext)
 {
 	ereport(WARNING, (errmsg("not propagating ALTER TABLE ALL IN TABLESPACE "
 							 "commands to worker nodes"),
@@ -743,7 +1002,8 @@ PreprocessAlterTableMoveAllStmt(Node *node, const char *queryString)
  * shards.
  */
 List *
-PreprocessAlterTableSchemaStmt(Node *node, const char *queryString)
+PreprocessAlterTableSchemaStmt(Node *node, const char *queryString,
+							   ProcessUtilityContext processUtilityContext)
 {
 	AlterObjectSchemaStmt *stmt = castNode(AlterObjectSchemaStmt, node);
 	Assert(stmt->objectType == OBJECT_TABLE);

src/backend/distributed/commands/trigger.c

@@ -483,7 +483,8 @@ GetAlterTriggerDependsTriggerNameValue(AlterObjectDependsStmt *alterTriggerDepen
  * standard process utility.
  */
 List *
-PreprocessDropTriggerStmt(Node *node, const char *queryString)
+PreprocessDropTriggerStmt(Node *node, const char *queryString,
+						  ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *dropTriggerStmt = castNode(DropStmt, node);
 	Assert(dropTriggerStmt->removeType == OBJECT_TRIGGER);

src/backend/distributed/commands/type.c

@@ -116,7 +116,8 @@ static bool ShouldPropagateTypeCreate(void);
  * access to the ObjectAddress of the new type.
  */
 List *
-PreprocessCompositeTypeStmt(Node *node, const char *queryString)
+PreprocessCompositeTypeStmt(Node *node, const char *queryString,
+							ProcessUtilityContext processUtilityContext)
 {
 	if (!ShouldPropagateTypeCreate())
 	{
@@ -201,7 +202,8 @@ PostprocessCompositeTypeStmt(Node *node, const char *queryString)
  * this is already implemented by the post processing for adding columns to tables.
  */
 List *
-PreprocessAlterTypeStmt(Node *node, const char *queryString)
+PreprocessAlterTypeStmt(Node *node, const char *queryString,
+						ProcessUtilityContext processUtilityContext)
 {
 	AlterTableStmt *stmt = castNode(AlterTableStmt, node);
 	Assert(stmt->relkind == OBJECT_TYPE);
@@ -244,7 +246,8 @@ PreprocessAlterTypeStmt(Node *node, const char *queryString)
  * ObjectAddress for the new type just yet.
  */
 List *
-PreprocessCreateEnumStmt(Node *node, const char *queryString)
+PreprocessCreateEnumStmt(Node *node, const char *queryString,
+						 ProcessUtilityContext processUtilityContext)
 {
 	if (!ShouldPropagateTypeCreate())
 	{
@@ -316,7 +319,8 @@ PostprocessCreateEnumStmt(Node *node, const char *queryString)
  * workers directly to keep the types in sync accross the cluster.
  */
 List *
-PreprocessAlterEnumStmt(Node *node, const char *queryString)
+PreprocessAlterEnumStmt(Node *node, const char *queryString,
+						ProcessUtilityContext processUtilityContext)
 {
 	List *commands = NIL;
 
@@ -446,7 +450,8 @@ PostprocessAlterEnumStmt(Node *node, const char *queryString)
  * no types in the drop list are distributed no calls will be made to the workers.
  */
 List *
-PreprocessDropTypeStmt(Node *node, const char *queryString)
+PreprocessDropTypeStmt(Node *node, const char *queryString,
+					   ProcessUtilityContext processUtilityContext)
 {
 	DropStmt *stmt = castNode(DropStmt, node);
 
@@ -514,7 +519,8 @@ PreprocessDropTypeStmt(Node *node, const char *queryString)
  * executed on all the workers to keep the types in sync across the cluster.
  */
 List *
-PreprocessRenameTypeStmt(Node *node, const char *queryString)
+PreprocessRenameTypeStmt(Node *node, const char *queryString,
+						 ProcessUtilityContext processUtilityContext)
 {
 	ObjectAddress typeAddress = GetObjectAddressFromParseTree(node, false);
 	if (!ShouldPropagateObject(&typeAddress))
@@ -547,7 +553,8 @@ PreprocessRenameTypeStmt(Node *node, const char *queryString)
  * keep the type in sync across the cluster.
  */
 List *
-PreprocessRenameTypeAttributeStmt(Node *node, const char *queryString)
+PreprocessRenameTypeAttributeStmt(Node *node, const char *queryString,
+								  ProcessUtilityContext processUtilityContext)
 {
 	RenameStmt *stmt = castNode(RenameStmt, node);
 	Assert(stmt->renameType == OBJECT_ATTRIBUTE);
@@ -579,7 +586,8 @@ PreprocessRenameTypeAttributeStmt(Node *node, const char *queryString)
  * In this stage we can prepare the commands that need to be run on all workers.
  */
 List *
-PreprocessAlterTypeSchemaStmt(Node *node, const char *queryString)
+PreprocessAlterTypeSchemaStmt(Node *node, const char *queryString,
+							  ProcessUtilityContext processUtilityContext)
 {
 	AlterObjectSchemaStmt *stmt = castNode(AlterObjectSchemaStmt, node);
 	Assert(stmt->objectType == OBJECT_TYPE);
@@ -637,7 +645,8 @@ PostprocessAlterTypeSchemaStmt(Node *node, const char *queryString)
  * the workers to keep the type in sync across the cluster.
  */
 List *
-PreprocessAlterTypeOwnerStmt(Node *node, const char *queryString)
+PreprocessAlterTypeOwnerStmt(Node *node, const char *queryString,
+							 ProcessUtilityContext processUtilityContext)
 {
 	AlterOwnerStmt *stmt = castNode(AlterOwnerStmt, node);
 	Assert(stmt->objectType == OBJECT_TYPE);

src/backend/distributed/commands/utility_hook.c

@@ -384,7 +384,7 @@ multi_ProcessUtility(PlannedStmt *pstmt,
 
 		if (ops && ops->preprocess)
 		{
-			ddlJobs = ops->preprocess(parsetree, queryString);
+			ddlJobs = ops->preprocess(parsetree, queryString, context);
 		}
 	}
 	else

src/include/distributed/commands.h

@@ -18,6 +18,7 @@
 #include "utils/rel.h"
 #include "nodes/parsenodes.h"
 #include "tcop/dest.h"
+#include "tcop/utility.h"
 
 /*
  * DistributeObjectOps specifies handlers for node/object type pairs.
@@ -39,7 +40,7 @@ typedef struct DistributeObjectOps
 {
 	char * (*deparse)(Node *);
 	void (*qualify)(Node *);
-	List * (*preprocess)(Node *, const char *);
+	List * (*preprocess)(Node *, const char *, ProcessUtilityContext);
 	List * (*postprocess)(Node *, const char *);
 	ObjectAddress (*address)(Node *, bool);
 } DistributeObjectOps;
@@ -102,7 +103,8 @@ typedef enum SearchForeignKeyColumnFlags
 
 
 /* cluster.c - forward declarations */
-extern List * PreprocessClusterStmt(Node *node, const char *clusterCommand);
+extern List * PreprocessClusterStmt(Node *node, const char *clusterCommand,
+									ProcessUtilityContext processUtilityContext);
 
 /* index.c */
 typedef void (*PGIndexProcessor)(Form_pg_index, List **);
@@ -116,10 +118,16 @@ extern bool CallDistributedProcedureRemotely(CallStmt *callStmt, DestReceiver *d
 extern char * CreateCollationDDL(Oid collationId);
 extern List * CreateCollationDDLsIdempotent(Oid collationId);
 extern ObjectAddress AlterCollationOwnerObjectAddress(Node *stmt, bool missing_ok);
-extern List * PreprocessDropCollationStmt(Node *stmt, const char *queryString);
+extern List * PreprocessDropCollationStmt(Node *stmt, const char *queryString,
-extern List * PreprocessAlterCollationOwnerStmt(Node *stmt, const char *queryString);
+										  ProcessUtilityContext processUtilityContext);
-extern List * PreprocessAlterCollationSchemaStmt(Node *stmt, const char *queryString);
+extern List * PreprocessAlterCollationOwnerStmt(Node *stmt, const char *queryString,
-extern List * PreprocessRenameCollationStmt(Node *stmt, const char *queryString);
+												ProcessUtilityContext
+												processUtilityContext);
+extern List * PreprocessAlterCollationSchemaStmt(Node *stmt, const char *queryString,
+												 ProcessUtilityContext
+												 processUtilityContext);
+extern List * PreprocessRenameCollationStmt(Node *stmt, const char *queryString,
+											ProcessUtilityContext processUtilityContext);
 extern ObjectAddress RenameCollationStmtObjectAddress(Node *stmt, bool missing_ok);
 extern ObjectAddress AlterCollationSchemaStmtObjectAddress(Node *stmt,
 														   bool missing_ok);
@@ -133,16 +141,23 @@ extern bool IsDropCitusExtensionStmt(Node *parsetree);
 extern bool IsCreateAlterExtensionUpdateCitusStmt(Node *parsetree);
 extern void ErrorIfUnstableCreateOrAlterExtensionStmt(Node *parsetree);
 extern List * PostprocessCreateExtensionStmt(Node *stmt, const char *queryString);
-extern List * PreprocessDropExtensionStmt(Node *stmt, const char *queryString);
+extern List * PreprocessDropExtensionStmt(Node *stmt, const char *queryString,
+										  ProcessUtilityContext processUtilityContext);
 extern List * PreprocessAlterExtensionSchemaStmt(Node *stmt,
-												 const char *queryString);
+												 const char *queryString,
+												 ProcessUtilityContext
+												 processUtilityContext);
 extern List * PostprocessAlterExtensionSchemaStmt(Node *stmt,
 												  const char *queryString);
 extern List * PreprocessAlterExtensionUpdateStmt(Node *stmt,
-												 const char *queryString);
+												 const char *queryString,
+												 ProcessUtilityContext
+												 processUtilityContext);
 extern void PostprocessAlterExtensionCitusUpdateStmt(Node *node);
 extern List * PreprocessAlterExtensionContentsStmt(Node *node,
-												   const char *queryString);
+												   const char *queryString,
+												   ProcessUtilityContext
+												   processUtilityContext);
 extern List * CreateExtensionDDLCommand(const ObjectAddress *extensionAddress);
 extern ObjectAddress AlterExtensionSchemaStmtObjectAddress(Node *stmt,
 														   bool missing_ok);
@@ -182,51 +197,64 @@ extern bool RelationInvolvedInAnyNonInheritedForeignKeys(Oid relationId);
 
 
 /* function.c - forward declarations */
-extern List * PreprocessCreateFunctionStmt(Node *stmt, const char *queryString);
+extern List * PreprocessCreateFunctionStmt(Node *stmt, const char *queryString,
+										   ProcessUtilityContext processUtilityContext);
 extern List * PostprocessCreateFunctionStmt(Node *stmt,
 											const char *queryString);
 extern ObjectAddress CreateFunctionStmtObjectAddress(Node *stmt,
 													 bool missing_ok);
 extern ObjectAddress DefineAggregateStmtObjectAddress(Node *stmt,
 													  bool missing_ok);
-extern List * PreprocessAlterFunctionStmt(Node *stmt, const char *queryString);
+extern List * PreprocessAlterFunctionStmt(Node *stmt, const char *queryString,
+										  ProcessUtilityContext processUtilityContext);
 extern ObjectAddress AlterFunctionStmtObjectAddress(Node *stmt,
 													bool missing_ok);
-extern List * PreprocessRenameFunctionStmt(Node *stmt, const char *queryString);
+extern List * PreprocessRenameFunctionStmt(Node *stmt, const char *queryString,
+										   ProcessUtilityContext processUtilityContext);
 extern ObjectAddress RenameFunctionStmtObjectAddress(Node *stmt,
 													 bool missing_ok);
-extern List * PreprocessAlterFunctionOwnerStmt(Node *stmt, const char *queryString);
+extern List * PreprocessAlterFunctionOwnerStmt(Node *stmt, const char *queryString,
+											   ProcessUtilityContext processUtilityContext);
 extern ObjectAddress AlterFunctionOwnerObjectAddress(Node *stmt,
 													 bool missing_ok);
-extern List * PreprocessAlterFunctionSchemaStmt(Node *stmt, const char *queryString);
+extern List * PreprocessAlterFunctionSchemaStmt(Node *stmt, const char *queryString,
+												ProcessUtilityContext
+												processUtilityContext);
 extern ObjectAddress AlterFunctionSchemaStmtObjectAddress(Node *stmt,
 														  bool missing_ok);
 extern List * PostprocessAlterFunctionSchemaStmt(Node *stmt,
 												 const char *queryString);
-extern List * PreprocessDropFunctionStmt(Node *stmt, const char *queryString);
+extern List * PreprocessDropFunctionStmt(Node *stmt, const char *queryString,
+										 ProcessUtilityContext processUtilityContext);
 extern List * PreprocessAlterFunctionDependsStmt(Node *stmt,
-												 const char *queryString);
+												 const char *queryString,
+												 ProcessUtilityContext
+												 processUtilityContext);
 extern ObjectAddress AlterFunctionDependsStmtObjectAddress(Node *stmt,
 														   bool missing_ok);
 
 
 /* grant.c - forward declarations */
-extern List * PreprocessGrantStmt(Node *node, const char *queryString);
+extern List * PreprocessGrantStmt(Node *node, const char *queryString,
+								  ProcessUtilityContext processUtilityContext);
 
 
 /* index.c - forward declarations */
 extern bool IsIndexRenameStmt(RenameStmt *renameStmt);
 extern List * PreprocessIndexStmt(Node *createIndexStatement,
-								  const char *createIndexCommand);
+								  const char *createIndexCommand,
+								  ProcessUtilityContext processUtilityContext);
 extern char * ChooseIndexName(const char *tabname, Oid namespaceId,
 							  List *colnames, List *exclusionOpNames,
 							  bool primary, bool isconstraint);
 extern char * ChooseIndexNameAddition(List *colnames);
 extern List * ChooseIndexColumnNames(List *indexElems);
 extern List * PreprocessReindexStmt(Node *ReindexStatement,
-									const char *ReindexCommand);
+									const char *ReindexCommand,
+									ProcessUtilityContext processUtilityContext);
 extern List * PreprocessDropIndexStmt(Node *dropIndexStatement,
-									  const char *dropIndexCommand);
+									  const char *dropIndexCommand,
+									  ProcessUtilityContext processUtilityContext);
 extern List * PostprocessIndexStmt(Node *node,
 								   const char *queryString);
 extern void ErrorIfUnsupportedAlterIndexStmt(AlterTableStmt *alterTableStatement);
@@ -241,9 +269,12 @@ extern ObjectAddress CreateExtensionStmtObjectAddress(Node *stmt, bool missing_o
 /* policy.c -  forward declarations */
 extern List * CreatePolicyCommands(Oid relationId);
 extern void ErrorIfUnsupportedPolicy(Relation relation);
-extern List * PreprocessCreatePolicyStmt(Node *node, const char *queryString);
+extern List * PreprocessCreatePolicyStmt(Node *node, const char *queryString,
-extern List * PreprocessAlterPolicyStmt(Node *node, const char *queryString);
+										 ProcessUtilityContext processUtilityContext);
-extern List * PreprocessDropPolicyStmt(Node *stmt, const char *queryString);
+extern List * PreprocessAlterPolicyStmt(Node *node, const char *queryString,
+										ProcessUtilityContext processUtilityContext);
+extern List * PreprocessDropPolicyStmt(Node *stmt, const char *queryString,
+									   ProcessUtilityContext processUtilityContext);
 extern bool IsPolicyRenameStmt(RenameStmt *stmt);
 extern void CreatePolicyEventExtendNames(CreatePolicyStmt *stmt, const char *schemaName,
 										 uint64 shardId);
@@ -256,14 +287,17 @@ extern void DropPolicyEventExtendNames(DropStmt *stmt, const char *schemaName, u
 
 
 /* rename.c - forward declarations*/
-extern List * PreprocessRenameStmt(Node *renameStmt, const char *renameCommand);
+extern List * PreprocessRenameStmt(Node *renameStmt, const char *renameCommand,
+								   ProcessUtilityContext processUtilityContext);
 extern void ErrorIfUnsupportedRenameStmt(RenameStmt *renameStmt);
-extern List * PreprocessRenameAttributeStmt(Node *stmt, const char *queryString);
+extern List * PreprocessRenameAttributeStmt(Node *stmt, const char *queryString,
+											ProcessUtilityContext processUtilityContext);
 
 
 /* role.c - forward declarations*/
 extern List * PostprocessAlterRoleStmt(Node *stmt, const char *queryString);
-extern List * PreprocessAlterRoleSetStmt(Node *stmt, const char *queryString);
+extern List * PreprocessAlterRoleSetStmt(Node *stmt, const char *queryString,
+										 ProcessUtilityContext processUtilityContext);
 extern List * GenerateAlterRoleSetCommandForRole(Oid roleid);
 extern ObjectAddress AlterRoleStmtObjectAddress(Node *node,
 												bool missing_ok);
@@ -273,11 +307,14 @@ extern List * GenerateCreateOrAlterRoleCommand(Oid roleOid);
 
 /* schema.c - forward declarations */
 extern List * PreprocessDropSchemaStmt(Node *dropSchemaStatement,
-									   const char *queryString);
+									   const char *queryString,
+									   ProcessUtilityContext processUtilityContext);
 extern List * PreprocessAlterObjectSchemaStmt(Node *alterObjectSchemaStmt,
 											  const char *alterObjectSchemaCommand);
-extern List * PreprocessGrantOnSchemaStmt(Node *node, const char *queryString);
+extern List * PreprocessGrantOnSchemaStmt(Node *node, const char *queryString,
-extern List * PreprocessAlterSchemaRenameStmt(Node *node, const char *queryString);
+										  ProcessUtilityContext processUtilityContext);
+extern List * PreprocessAlterSchemaRenameStmt(Node *node, const char *queryString,
+											  ProcessUtilityContext processUtilityContext);
 extern ObjectAddress AlterSchemaRenameStmtObjectAddress(Node *node, bool missing_ok);
 
 /* sequence.c - forward declarations */
@@ -285,16 +322,25 @@ extern void ErrorIfUnsupportedSeqStmt(CreateSeqStmt *createSeqStmt);
 extern void ErrorIfDistributedAlterSeqOwnedBy(AlterSeqStmt *alterSeqStmt);
 
 /* statistics.c - forward declarations */
-extern List * PreprocessCreateStatisticsStmt(Node *node, const char *queryString);
+extern List * PreprocessCreateStatisticsStmt(Node *node, const char *queryString,
+											 ProcessUtilityContext processUtilityContext);
 extern List * PostprocessCreateStatisticsStmt(Node *node, const char *queryString);
 extern ObjectAddress CreateStatisticsStmtObjectAddress(Node *node, bool missingOk);
-extern List * PreprocessDropStatisticsStmt(Node *node, const char *queryString);
+extern List * PreprocessDropStatisticsStmt(Node *node, const char *queryString,
-extern List * PreprocessAlterStatisticsRenameStmt(Node *node, const char *queryString);
+										   ProcessUtilityContext processUtilityContext);
-extern List * PreprocessAlterStatisticsSchemaStmt(Node *node, const char *queryString);
+extern List * PreprocessAlterStatisticsRenameStmt(Node *node, const char *queryString,
+												  ProcessUtilityContext
+												  processUtilityContext);
+extern List * PreprocessAlterStatisticsSchemaStmt(Node *node, const char *queryString,
+												  ProcessUtilityContext
+												  processUtilityContext);
 extern List * PostprocessAlterStatisticsSchemaStmt(Node *node, const char *queryString);
 extern ObjectAddress AlterStatisticsSchemaStmtObjectAddress(Node *node, bool missingOk);
-extern List * PreprocessAlterStatisticsStmt(Node *node, const char *queryString);
+extern List * PreprocessAlterStatisticsStmt(Node *node, const char *queryString,
-extern List * PreprocessAlterStatisticsOwnerStmt(Node *node, const char *queryString);
+											ProcessUtilityContext processUtilityContext);
+extern List * PreprocessAlterStatisticsOwnerStmt(Node *node, const char *queryString,
+												 ProcessUtilityContext
+												 processUtilityContext);
 extern List * GetExplicitStatisticsCommandList(Oid relationId);
 extern List * GetExplicitStatisticsSchemaIdList(Oid relationId);
 
@@ -303,16 +349,20 @@ extern Node * ProcessCreateSubscriptionStmt(CreateSubscriptionStmt *createSubStm
 
 
 /* table.c - forward declarations */
-extern List * PreprocessDropTableStmt(Node *stmt, const char *queryString);
+extern List * PreprocessDropTableStmt(Node *stmt, const char *queryString,
+									  ProcessUtilityContext processUtilityContext);
 extern void PostprocessCreateTableStmt(CreateStmt *createStatement,
 									   const char *queryString);
 extern List * PostprocessAlterTableStmtAttachPartition(
 	AlterTableStmt *alterTableStatement,
 	const char *queryString);
 extern List * PostprocessAlterTableSchemaStmt(Node *node, const char *queryString);
-extern List * PreprocessAlterTableStmt(Node *node, const char *alterTableCommand);
+extern List * PreprocessAlterTableStmt(Node *node, const char *alterTableCommand,
-extern List * PreprocessAlterTableMoveAllStmt(Node *node, const char *queryString);
+									   ProcessUtilityContext processUtilityContext);
-extern List * PreprocessAlterTableSchemaStmt(Node *node, const char *queryString);
+extern List * PreprocessAlterTableMoveAllStmt(Node *node, const char *queryString,
+											  ProcessUtilityContext processUtilityContext);
+extern List * PreprocessAlterTableSchemaStmt(Node *node, const char *queryString,
+											 ProcessUtilityContext processUtilityContext);
 extern Node * WorkerProcessAlterTableStmt(AlterTableStmt *alterTableStatement,
 										  const char *alterTableCommand);
 extern bool IsAlterTableRenameStmt(RenameStmt *renameStmt);
@@ -332,18 +382,28 @@ extern List * MakeNameListFromRangeVar(const RangeVar *rel);
 extern void PreprocessTruncateStatement(TruncateStmt *truncateStatement);
 
 /* type.c - forward declarations */
-extern List * PreprocessCompositeTypeStmt(Node *stmt, const char *queryString);
+extern List * PreprocessCompositeTypeStmt(Node *stmt, const char *queryString,
+										  ProcessUtilityContext processUtilityContext);
 extern List * PostprocessCompositeTypeStmt(Node *stmt, const char *queryString);
-extern List * PreprocessAlterTypeStmt(Node *stmt, const char *queryString);
+extern List * PreprocessAlterTypeStmt(Node *stmt, const char *queryString,
-extern List * PreprocessCreateEnumStmt(Node *stmt, const char *queryString);
+									  ProcessUtilityContext processUtilityContext);
+extern List * PreprocessCreateEnumStmt(Node *stmt, const char *queryString,
+									   ProcessUtilityContext processUtilityContext);
 extern List * PostprocessCreateEnumStmt(Node *stmt, const char *queryString);
-extern List * PreprocessAlterEnumStmt(Node *stmt, const char *queryString);
+extern List * PreprocessAlterEnumStmt(Node *stmt, const char *queryString,
+									  ProcessUtilityContext processUtilityContext);
 extern List * PostprocessAlterEnumStmt(Node *stmt, const char *queryString);
-extern List * PreprocessDropTypeStmt(Node *stmt, const char *queryString);
+extern List * PreprocessDropTypeStmt(Node *stmt, const char *queryString,
-extern List * PreprocessRenameTypeStmt(Node *stmt, const char *queryString);
+									 ProcessUtilityContext processUtilityContext);
-extern List * PreprocessRenameTypeAttributeStmt(Node *stmt, const char *queryString);
+extern List * PreprocessRenameTypeStmt(Node *stmt, const char *queryString,
-extern List * PreprocessAlterTypeSchemaStmt(Node *stmt, const char *queryString);
+									   ProcessUtilityContext processUtilityContext);
-extern List * PreprocessAlterTypeOwnerStmt(Node *stmt, const char *queryString);
+extern List * PreprocessRenameTypeAttributeStmt(Node *stmt, const char *queryString,
+												ProcessUtilityContext
+												processUtilityContext);
+extern List * PreprocessAlterTypeSchemaStmt(Node *stmt, const char *queryString,
+											ProcessUtilityContext processUtilityContext);
+extern List * PreprocessAlterTypeOwnerStmt(Node *stmt, const char *queryString,
+										   ProcessUtilityContext processUtilityContext);
 extern List * PostprocessAlterTypeSchemaStmt(Node *stmt, const char *queryString);
 extern Node * CreateTypeStmtByObjectAddress(const ObjectAddress *address);
 extern ObjectAddress CompositeTypeStmtObjectAddress(Node *stmt, bool missing_ok);
@@ -384,7 +444,8 @@ extern List * PostprocessAlterTriggerDependsStmt(Node *node, const char *querySt
 extern void AlterTriggerDependsEventExtendNames(
 	AlterObjectDependsStmt *alterTriggerDependsStmt,
 	char *schemaName, uint64 shardId);
-extern List * PreprocessDropTriggerStmt(Node *node, const char *queryString);
+extern List * PreprocessDropTriggerStmt(Node *node, const char *queryString,
+										ProcessUtilityContext processUtilityContext);
 extern void ErrorOutForTriggerIfNotCitusLocalTable(Oid relationId);
 extern void DropTriggerEventExtendNames(DropStmt *dropTriggerStmt, char *schemaName,
 										uint64 shardId);
@@ -423,4 +484,8 @@ extern void CreateCitusLocalTable(Oid relationId, bool cascadeViaForeignKeys);
 extern bool ShouldPropagateSetCommand(VariableSetStmt *setStmt);
 extern void PostprocessVariableSetStmt(VariableSetStmt *setStmt, const char *setCommand);
 
+/* create_citus_local_table.c */
+
+extern void CreateCitusLocalTable(Oid relationId, bool cascade);
+
 #endif /*CITUS_COMMANDS_H */

src/test/regress/expected/citus_local_tables.out

@@ -413,8 +413,6 @@ NOTICE:  executing the command locally: CREATE UNIQUE INDEX   uniqueindex2_15040
 ---- utility command execution ----
 ---------------------------------------------------------------------
 SET search_path TO citus_local_tables_test_schema;
--- any foreign key between citus local tables and other tables except reference tables cannot be set
--- more tests at ref_citus_local_fkeys.sql
 -- between citus local tables and distributed tables
 ALTER TABLE citus_local_table_1 ADD CONSTRAINT fkey_c_to_dist FOREIGN KEY(a) references distributed_table(a);
 ERROR:  cannot create foreign key constraint since foreign keys from reference tables and citus local tables to distributed tables are not supported
@@ -422,15 +420,15 @@ ALTER TABLE distributed_table ADD CONSTRAINT fkey_dist_to_c FOREIGN KEY(a) refer
 ERROR:  cannot create foreign key constraint since relations are not colocated or not referencing a reference table
 -- between citus local tables and local tables
 ALTER TABLE citus_local_table_1 ADD CONSTRAINT fkey_c_to_local FOREIGN KEY(a) references local_table(a);
-ERROR:  cannot create foreign key constraint as "local_table" is a postgres local table
+NOTICE:  executing the command locally: SELECT worker_apply_inter_shard_ddl_command (1504027, 'citus_local_tables_test_schema', 1504037, 'citus_local_tables_test_schema', 'ALTER TABLE citus_local_table_1 ADD CONSTRAINT fkey_c_to_local FOREIGN KEY(a) references local_table(a);')
 ALTER TABLE local_table
   ADD CONSTRAINT fkey_local_to_c FOREIGN KEY(a) references citus_local_table_1(a),
   ADD CONSTRAINT fkey_self FOREIGN KEY(a) references local_table(a);
-ERROR:  cannot create foreign key constraint as "local_table" is a postgres local table
+ERROR:  cannot execute ADD CONSTRAINT command with other subcommands
 ALTER TABLE local_table
   ADD COLUMN b int references citus_local_table_1(a),
   ADD COLUMN c int references local_table(a);
-ERROR:  cannot create foreign key constraint as "local_table" is a postgres local table
+ERROR:  cannot execute ADD COLUMN command with PRIMARY KEY, UNIQUE, FOREIGN and CHECK constraints
 CREATE TABLE local_table_4 (
   a int unique references citus_local_table_1(a),
   b int references local_table_4(a));
@@ -478,6 +476,8 @@ ORDER BY 1;
 TRUNCATE citus_local_table_1, citus_local_table_2, distributed_table, local_table, reference_table;
 NOTICE:  executing the command locally: TRUNCATE TABLE citus_local_tables_test_schema.citus_local_table_1_xxxxx CASCADE
 NOTICE:  executing the command locally: TRUNCATE TABLE citus_local_tables_test_schema.citus_local_table_2_xxxxx CASCADE
+NOTICE:  executing the command locally: TRUNCATE TABLE citus_local_tables_test_schema.local_table_xxxxx CASCADE
+NOTICE:  truncate cascades to table "citus_local_table_1_xxxxxxx"
 NOTICE:  executing the command locally: TRUNCATE TABLE citus_local_tables_test_schema.reference_table_xxxxx CASCADE
 -- test vacuum
 VACUUM citus_local_table_1;
@@ -485,6 +485,8 @@ VACUUM citus_local_table_1, distributed_table, local_table, reference_table;
 -- test drop
 DROP TABLE citus_local_table_1, citus_local_table_2, distributed_table, local_table, reference_table;
 NOTICE:  executing the command locally: DROP TABLE IF EXISTS citus_local_tables_test_schema.reference_table_xxxxx CASCADE
+NOTICE:  executing the command locally: DROP TABLE IF EXISTS citus_local_tables_test_schema.local_table_xxxxx CASCADE
+NOTICE:  drop cascades to constraint fkey_c_to_local_1504027 on table citus_local_tables_test_schema.citus_local_table_1_1504027
 NOTICE:  executing the command locally: DROP TABLE IF EXISTS citus_local_tables_test_schema.citus_local_table_2_xxxxx CASCADE
 NOTICE:  executing the command locally: DROP TABLE IF EXISTS citus_local_tables_test_schema.citus_local_table_1_xxxxx CASCADE
 -- test some other udf's with citus local tables
@@ -498,9 +500,9 @@ SELECT create_citus_local_table('citus_local_table_4');
 -- should work --
 -- insert some data & create an index for table size udf's
 INSERT INTO citus_local_table_4 VALUES (1), (2), (3);
-NOTICE:  executing the command locally: INSERT INTO citus_local_tables_test_schema.citus_local_table_4_1504037 AS citus_table_alias (a) VALUES (1), (2), (3)
+NOTICE:  executing the command locally: INSERT INTO citus_local_tables_test_schema.citus_local_table_4_1504038 AS citus_table_alias (a) VALUES (1), (2), (3)
 CREATE INDEX citus_local_table_4_idx ON citus_local_table_4(a);
-NOTICE:  executing the command locally: CREATE  INDEX   citus_local_table_4_idx_1504037 ON citus_local_tables_test_schema.citus_local_table_4_1504037 USING btree (a )
+NOTICE:  executing the command locally: CREATE  INDEX   citus_local_table_4_idx_1504038 ON citus_local_tables_test_schema.citus_local_table_4_1504038 USING btree (a )
 SELECT citus_table_size('citus_local_table_4');
  citus_table_size
 ---------------------------------------------------------------------
@@ -587,7 +589,7 @@ BEGIN;
   SELECT tableName FROM pg_catalog.pg_tables WHERE tablename LIKE 'citus_local_table_4%';
           tablename
 ---------------------------------------------------------------------
- citus_local_table_4_1504037
+ citus_local_table_4_1504038
 (1 row)
 
 ROLLBACK;
@@ -596,7 +598,7 @@ SELECT shardid, get_colocated_shard_array(shardid)
 FROM (SELECT shardid FROM pg_dist_shard WHERE logicalrelid='citus_local_table_4'::regclass) as shardid;
  shardid | get_colocated_shard_array
 ---------------------------------------------------------------------
- 1504037 | {1504037}
+ 1504038 | {1504038}
 (1 row)
 
 BEGIN;
@@ -626,7 +628,7 @@ ERROR:  cannot delete from table
 CREATE TABLE postgres_local_table (a int);
 SELECT master_append_table_to_shard(shardId, 'postgres_local_table', 'localhost', :master_port)
 FROM (SELECT shardid FROM pg_dist_shard WHERE logicalrelid='citus_local_table_4'::regclass) as shardid;
-ERROR:  cannot append to shardId 1504037
+ERROR:  cannot append to shardId 1504038
 -- return true
 SELECT citus_table_is_visible('citus_local_table_4'::regclass::oid);
  citus_table_is_visible
@@ -667,7 +669,7 @@ SELECT create_citus_local_table('referenced_table');
 (1 row)
 
 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 (1504038, 'citus_local_tables_test_schema', 1504039, 'citus_local_tables_test_schema', '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 (1504039, 'citus_local_tables_test_schema', 1504040, 'citus_local_tables_test_schema', 'ALTER TABLE referencing_table ADD CONSTRAINT fkey_cl_to_cl FOREIGN KEY (a) REFERENCES referenced_table(a);')
 -- observe the debug messages telling that we switch to sequential
 -- execution when truncating a citus local table that is referenced
 -- by another table

src/test/regress/expected/fkeys_between_local_ref.out

@@ -0,0 +1,231 @@
+\set VERBOSITY terse
+SET citus.next_shard_id TO 1518000;
+SET citus.shard_replication_factor TO 1;
+CREATE SCHEMA fkeys_between_local_ref;
+SET search_path TO fkeys_between_local_ref;
+SET client_min_messages to ERROR;
+-- create a view for testing
+CREATE VIEW citus_local_tables_in_schema AS
+SELECT logicalrelid FROM pg_dist_partition, pg_tables
+WHERE tablename=logicalrelid::regclass::text AND
+      schemaname='fkeys_between_local_ref' AND
+      partmethod = 'n' AND repmodel = 'c';
+-- remove coordinator if it is added to pg_dist_node and test
+-- behavior when coordinator is not added to metadata
+SELECT COUNT(master_remove_node(nodename, nodeport)) < 2
+FROM pg_dist_node WHERE nodename='localhost' AND nodeport=:master_port;
+ ?column?
+---------------------------------------------------------------------
+ t
+(1 row)
+
+create table ref (a int primary key);
+select create_reference_table('ref');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+-- creating local table that references to reference table is supported
+create table other (x int primary key, y int);
+-- creating reference table from a local table that references
+-- to reference table is supported
+alter table other add constraint fk foreign key (y) references ref (a) on delete cascade;
+select create_reference_table('other');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+drop table if exists ref, ref2 cascade;
+create table ref (a int primary key);
+create table ref2 (x int);
+alter table ref2 add constraint fk foreign key (x) references ref (a);
+select create_reference_table('ref');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+-- we can also define more foreign keys after creating reference
+-- table from referenced table
+alter table ref2 add constraint fk2 foreign key (x) references ref (a);
+-- then we can create reference table from referencing table
+select create_reference_table('ref2');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+drop table if exists ref, ref2, other cascade;
+-- add coordinator to pg_dist_node for rest of the tests
+SELECT 1 FROM master_add_node('localhost', :master_port, groupId => 0);
+ ?column?
+---------------------------------------------------------------------
+        1
+(1 row)
+
+CREATE TABLE local_table_1 (col_1 INT UNIQUE);
+CREATE TABLE local_table_2 (col_1 INT UNIQUE);
+CREATE TABLE local_table_3 (col_1 INT UNIQUE);
+CREATE TABLE local_table_4 (col_1 INT UNIQUE);
+INSERT INTO local_table_1 SELECT i FROM generate_series(195, 205) i;
+INSERT INTO local_table_2 SELECT i FROM generate_series(195, 205) i;
+INSERT INTO local_table_3 SELECT i FROM generate_series(195, 205) i;
+INSERT INTO local_table_4 SELECT i FROM generate_series(195, 205) i;
+--                                        _
+--                                       | |
+--                                       | v
+-- local_table_2 -> local_table_1 -> local_table_4
+--                      ^ |               |
+--                      | v               |
+--                  local_table_3 <--------
+ALTER TABLE local_table_2 ADD CONSTRAINT fkey_1 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
+ALTER TABLE local_table_3 ADD CONSTRAINT fkey_2 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey_3 FOREIGN KEY (col_1) REFERENCES local_table_3(col_1);
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey_4 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
+ALTER TABLE local_table_4 ADD CONSTRAINT fkey_5 FOREIGN KEY (col_1) REFERENCES local_table_3(col_1);
+ALTER TABLE local_table_4 ADD CONSTRAINT fkey_6 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
+CREATE TABLE reference_table_1(col_1 INT UNIQUE, col_2 INT);
+INSERT INTO reference_table_1 SELECT i FROM generate_series(195, 205) i;
+SELECT create_reference_table('reference_table_1');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+CREATE TABLE partitioned_table_1 (col_1 INT, col_2 INT) PARTITION BY RANGE (col_1);
+CREATE TABLE partitioned_table_1_100_200 PARTITION OF partitioned_table_1 FOR VALUES FROM (100) TO (200);
+CREATE TABLE partitioned_table_1_200_300 PARTITION OF partitioned_table_1 FOR VALUES FROM (200) TO (300);
+INSERT INTO partitioned_table_1 SELECT i FROM generate_series(195, 205) i;
+ALTER TABLE partitioned_table_1 ADD CONSTRAINT fkey_8 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
+-- now that we attached partitioned table to graph below errors out
+-- since we cannot create citus local table from partitioned tables
+ALTER TABLE reference_table_1 ADD CONSTRAINT fkey_9 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
+ERROR:  cannot create citus local table "partitioned_table_1", only regular tables and foreign tables are supported for citus local table creation
+ALTER TABLE partitioned_table_1 DROP CONSTRAINT fkey_8;
+BEGIN;
+  -- now that we detached partitioned table from graph, succeeds
+  ALTER TABLE reference_table_1 ADD CONSTRAINT fkey_10 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
+  -- show that we converted all 4 local tables in this schema to citus local tables
+  SELECT COUNT(*)=4 FROM citus_local_tables_in_schema;
+ ?column?
+---------------------------------------------------------------------
+ t
+(1 row)
+
+ROLLBACK;
+-- this actually attempts to convert local tables to citus local tables but errors out
+-- as citus doesn't support defining foreign keys via add column commands
+ALTER TABLE local_table_1 ADD COLUMN col_3 INT REFERENCES reference_table_1(col_1);
+ERROR:  cannot execute ADD COLUMN command with PRIMARY KEY, UNIQUE, FOREIGN and CHECK constraints
+BEGIN;
+  -- define a foreign key so that all 4 local tables become citus local tables
+  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_1(col_1);
+  CREATE TABLE local_table_5 (col_1 INT UNIQUE);
+  -- now define foreign key from local to citus local table
+  ALTER TABLE local_table_5 ADD CONSTRAINT fkey_12 FOREIGN KEY (col_1) REFERENCES local_table_2(col_1);
+  -- now we have 5 citus local tables in this schema
+  SELECT COUNT(*)=5 FROM citus_local_tables_in_schema;
+ ?column?
+---------------------------------------------------------------------
+ t
+(1 row)
+
+ROLLBACK;
+-- they fail as local_table_99 does not exist
+ALTER TABLE local_table_99 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_1);
+ERROR:  relation "local_table_99" does not exist
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES local_table_99(col_1);
+ERROR:  relation "local_table_99" does not exist
+-- they fail as col_99 does not exist
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_99) REFERENCES reference_table_1(col_1);
+ERROR:  column "col_99" referenced in foreign key constraint does not exist
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_99);
+ERROR:  column "col_99" referenced in foreign key constraint does not exist
+-- fails as col_2 does not have a unique/primary key constraint
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_2);
+ERROR:  there is no unique constraint matching given keys for referenced table "reference_table_1"
+CREATE TABLE reference_table_2 (col_1 INT UNIQUE, col_2 INT);
+INSERT INTO reference_table_2 SELECT i FROM generate_series(195, 205) i;
+BEGIN;
+  -- define foreign key when both ends are local tables
+  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1);
+  -- we still don't convert local tables to citus local tables when
+  -- creating reference tables
+  SELECT create_reference_table('reference_table_2');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+  -- now defining another foreign key would convert local tables to
+  -- citus local tables as reference_table_2 is now a reference table
+  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_12 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1);
+  -- now print metadata to show that everyting is fine
+  SELECT logicalrelid::text AS tablename, partmethod, repmodel FROM pg_dist_partition
+  WHERE logicalrelid::text IN (SELECT tablename FROM pg_tables WHERE schemaname='fkeys_between_local_ref')
+  ORDER BY tablename;
+     tablename     | partmethod | repmodel
+---------------------------------------------------------------------
+ local_table_1     | n          | c
+ local_table_2     | n          | c
+ local_table_3     | n          | c
+ local_table_4     | n          | c
+ reference_table_1 | n          | t
+ reference_table_2 | n          | t
+(6 rows)
+
+ROLLBACK;
+-- we don't support foreign keys from citus local to reference tables
+-- with ON DELETE/UPDATE CASCADE behavior, so below two errors out
+BEGIN;
+  SELECT create_reference_table('reference_table_2');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+  ALTER TABLE reference_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES local_table_2(col_1) ON DELETE CASCADE;
+ERROR:  cannot define foreign key constraint, foreign keys from reference tables to citus local tables can only be defined with NO ACTION or RESTRICT behaviors
+ROLLBACK;
+BEGIN;
+  SELECT create_reference_table('reference_table_2');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+  ALTER TABLE reference_table_2 ADD CONSTRAINT fkey_local_to_ref FOREIGN KEY (col_1) REFERENCES local_table_2(col_1) ON UPDATE CASCADE;
+ERROR:  cannot define foreign key constraint, foreign keys from reference tables to citus local tables can only be defined with NO ACTION or RESTRICT behaviors
+ROLLBACK;
+-- but we support such foreign key behaviors when foreign key is from
+-- citus local to reference table
+BEGIN;
+  SELECT create_reference_table('reference_table_2');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+  ALTER TABLE local_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1) ON DELETE CASCADE;
+  DELETE FROM reference_table_2 WHERE col_1=200;
+  -- we deleted one row as DELETE cascades, so we should have 10 rows
+  SELECT COUNT(*) FROM local_table_2;
+ count
+---------------------------------------------------------------------
+    10
+(1 row)
+
+ROLLBACK;
+BEGIN;
+  SELECT create_reference_table('reference_table_2');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+  ALTER TABLE local_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1) ON UPDATE CASCADE;
+ROLLBACK;
+-- cleanup at exit
+DROP SCHEMA fkeys_between_local_ref CASCADE;

src/test/regress/expected/multi_foreign_key.out

@@ -26,17 +26,17 @@ DROP TABLE referencing_table;
 CREATE TABLE referencing_table(id int, ref_id int, FOREIGN KEY(ref_id) REFERENCES referenced_table(id) ON UPDATE SET NULL);
 SELECT create_distributed_table('referencing_table', 'ref_id', 'hash');
 ERROR:  cannot create foreign key constraint
-DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation  when distribution key included in the foreign constraint.
+DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation when distribution key included in the foreign constraint.
 DROP TABLE referencing_table;
 CREATE TABLE referencing_table(id int, ref_id int, FOREIGN KEY(ref_id) REFERENCES referenced_table(id) ON UPDATE SET DEFAULT);
 SELECT create_distributed_table('referencing_table', 'ref_id', 'hash');
 ERROR:  cannot create foreign key constraint
-DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation  when distribution key included in the foreign constraint.
+DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation when distribution key included in the foreign constraint.
 DROP TABLE referencing_table;
 CREATE TABLE referencing_table(id int, ref_id int, FOREIGN KEY(ref_id) REFERENCES referenced_table(id) ON UPDATE CASCADE);
 SELECT create_distributed_table('referencing_table', 'ref_id', 'hash');
 ERROR:  cannot create foreign key constraint
-DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation  when distribution key included in the foreign constraint.
+DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation when distribution key included in the foreign constraint.
 DROP TABLE referencing_table;
 -- self referencing table with replication factor > 1
 CREATE TABLE self_referencing_table(id int, ref_id int, PRIMARY KEY (id, ref_id), FOREIGN KEY(id,ref_id) REFERENCES self_referencing_table(id, ref_id));
@@ -448,13 +448,13 @@ ERROR:  cannot create foreign key constraint
 DETAIL:  SET NULL or SET DEFAULT is not supported in ON DELETE operation when distribution key is included in the foreign key constraint
 ALTER TABLE referencing_table ADD CONSTRAINT test_constraint FOREIGN KEY(ref_id) REFERENCES referenced_table(id) ON UPDATE SET NULL;
 ERROR:  cannot create foreign key constraint
-DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation  when distribution key included in the foreign constraint.
+DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation when distribution key included in the foreign constraint.
 ALTER TABLE referencing_table ADD CONSTRAINT test_constraint FOREIGN KEY(ref_id) REFERENCES referenced_table(id) ON UPDATE SET DEFAULT;
 ERROR:  cannot create foreign key constraint
-DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation  when distribution key included in the foreign constraint.
+DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation when distribution key included in the foreign constraint.
 ALTER TABLE referencing_table ADD CONSTRAINT test_constraint FOREIGN KEY(ref_id) REFERENCES referenced_table(id) ON UPDATE CASCADE;
 ERROR:  cannot create foreign key constraint
-DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation  when distribution key included in the foreign constraint.
+DETAIL:  SET NULL, SET DEFAULT or CASCADE is not supported in ON UPDATE operation when distribution key included in the foreign constraint.
 -- test foreign constraint creation while adding the column
 ALTER TABLE referencing_table ADD COLUMN referencing_col int REFERENCES referenced_table(id) ON UPDATE CASCADE;;
 ERROR:  cannot create foreign key constraint

src/test/regress/multi_schedule

@@ -327,6 +327,7 @@ test: citus_local_tables
 test: multi_row_router_insert mixed_relkind_tests create_ref_dist_from_citus_local
 test: undistribute_table_cascade
 test: create_citus_local_table_cascade
+test: fkeys_between_local_ref
 
 test: remove_coordinator
 

src/test/regress/sql/citus_local_tables.sql

@@ -313,9 +313,6 @@ CREATE UNIQUE INDEX uniqueIndex2 ON "LocalTabLE.1!?!"(id);
 
 SET search_path TO citus_local_tables_test_schema;
 
--- any foreign key between citus local tables and other tables except reference tables cannot be set
--- more tests at ref_citus_local_fkeys.sql
-
 -- between citus local tables and distributed tables
 ALTER TABLE citus_local_table_1 ADD CONSTRAINT fkey_c_to_dist FOREIGN KEY(a) references distributed_table(a);
 ALTER TABLE distributed_table ADD CONSTRAINT fkey_dist_to_c FOREIGN KEY(a) references citus_local_table_1(a);

src/test/regress/sql/fkeys_between_local_ref.sql

@@ -0,0 +1,179 @@
+\set VERBOSITY terse
+
+SET citus.next_shard_id TO 1518000;
+SET citus.shard_replication_factor TO 1;
+
+CREATE SCHEMA fkeys_between_local_ref;
+SET search_path TO fkeys_between_local_ref;
+
+SET client_min_messages to ERROR;
+
+-- create a view for testing
+CREATE VIEW citus_local_tables_in_schema AS
+SELECT logicalrelid FROM pg_dist_partition, pg_tables
+WHERE tablename=logicalrelid::regclass::text AND
+      schemaname='fkeys_between_local_ref' AND
+      partmethod = 'n' AND repmodel = 'c';
+
+
+-- remove coordinator if it is added to pg_dist_node and test
+-- behavior when coordinator is not added to metadata
+SELECT COUNT(master_remove_node(nodename, nodeport)) < 2
+FROM pg_dist_node WHERE nodename='localhost' AND nodeport=:master_port;
+
+create table ref (a int primary key);
+select create_reference_table('ref');
+-- creating local table that references to reference table is supported
+create table other (x int primary key, y int);
+
+-- creating reference table from a local table that references
+-- to reference table is supported
+alter table other add constraint fk foreign key (y) references ref (a) on delete cascade;
+select create_reference_table('other');
+
+drop table if exists ref, ref2 cascade;
+
+create table ref (a int primary key);
+create table ref2 (x int);
+alter table ref2 add constraint fk foreign key (x) references ref (a);
+select create_reference_table('ref');
+-- we can also define more foreign keys after creating reference
+-- table from referenced table
+alter table ref2 add constraint fk2 foreign key (x) references ref (a);
+-- then we can create reference table from referencing table
+select create_reference_table('ref2');
+
+drop table if exists ref, ref2, other cascade;
+
+
+-- add coordinator to pg_dist_node for rest of the tests
+SELECT 1 FROM master_add_node('localhost', :master_port, groupId => 0);
+
+CREATE TABLE local_table_1 (col_1 INT UNIQUE);
+CREATE TABLE local_table_2 (col_1 INT UNIQUE);
+CREATE TABLE local_table_3 (col_1 INT UNIQUE);
+CREATE TABLE local_table_4 (col_1 INT UNIQUE);
+INSERT INTO local_table_1 SELECT i FROM generate_series(195, 205) i;
+INSERT INTO local_table_2 SELECT i FROM generate_series(195, 205) i;
+INSERT INTO local_table_3 SELECT i FROM generate_series(195, 205) i;
+INSERT INTO local_table_4 SELECT i FROM generate_series(195, 205) i;
+
+--                                        _
+--                                       | |
+--                                       | v
+-- local_table_2 -> local_table_1 -> local_table_4
+--                      ^ |               |
+--                      | v               |
+--                  local_table_3 <--------
+ALTER TABLE local_table_2 ADD CONSTRAINT fkey_1 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
+ALTER TABLE local_table_3 ADD CONSTRAINT fkey_2 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey_3 FOREIGN KEY (col_1) REFERENCES local_table_3(col_1);
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey_4 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
+ALTER TABLE local_table_4 ADD CONSTRAINT fkey_5 FOREIGN KEY (col_1) REFERENCES local_table_3(col_1);
+ALTER TABLE local_table_4 ADD CONSTRAINT fkey_6 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
+
+CREATE TABLE reference_table_1(col_1 INT UNIQUE, col_2 INT);
+INSERT INTO reference_table_1 SELECT i FROM generate_series(195, 205) i;
+SELECT create_reference_table('reference_table_1');
+
+CREATE TABLE partitioned_table_1 (col_1 INT, col_2 INT) PARTITION BY RANGE (col_1);
+CREATE TABLE partitioned_table_1_100_200 PARTITION OF partitioned_table_1 FOR VALUES FROM (100) TO (200);
+CREATE TABLE partitioned_table_1_200_300 PARTITION OF partitioned_table_1 FOR VALUES FROM (200) TO (300);
+INSERT INTO partitioned_table_1 SELECT i FROM generate_series(195, 205) i;
+
+ALTER TABLE partitioned_table_1 ADD CONSTRAINT fkey_8 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
+
+-- now that we attached partitioned table to graph below errors out
+-- since we cannot create citus local table from partitioned tables
+ALTER TABLE reference_table_1 ADD CONSTRAINT fkey_9 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
+
+ALTER TABLE partitioned_table_1 DROP CONSTRAINT fkey_8;
+
+BEGIN;
+  -- now that we detached partitioned table from graph, succeeds
+  ALTER TABLE reference_table_1 ADD CONSTRAINT fkey_10 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
+
+  -- show that we converted all 4 local tables in this schema to citus local tables
+  SELECT COUNT(*)=4 FROM citus_local_tables_in_schema;
+ROLLBACK;
+
+-- this actually attempts to convert local tables to citus local tables but errors out
+-- as citus doesn't support defining foreign keys via add column commands
+ALTER TABLE local_table_1 ADD COLUMN col_3 INT REFERENCES reference_table_1(col_1);
+
+BEGIN;
+  -- define a foreign key so that all 4 local tables become citus local tables
+  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_1(col_1);
+
+  CREATE TABLE local_table_5 (col_1 INT UNIQUE);
+  -- now define foreign key from local to citus local table
+  ALTER TABLE local_table_5 ADD CONSTRAINT fkey_12 FOREIGN KEY (col_1) REFERENCES local_table_2(col_1);
+
+  -- now we have 5 citus local tables in this schema
+  SELECT COUNT(*)=5 FROM citus_local_tables_in_schema;
+ROLLBACK;
+
+-- they fail as local_table_99 does not exist
+ALTER TABLE local_table_99 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_1);
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES local_table_99(col_1);
+
+-- they fail as col_99 does not exist
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_99) REFERENCES reference_table_1(col_1);
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_99);
+
+-- fails as col_2 does not have a unique/primary key constraint
+ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_2);
+
+CREATE TABLE reference_table_2 (col_1 INT UNIQUE, col_2 INT);
+INSERT INTO reference_table_2 SELECT i FROM generate_series(195, 205) i;
+
+BEGIN;
+  -- define foreign key when both ends are local tables
+  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1);
+
+  -- we still don't convert local tables to citus local tables when
+  -- creating reference tables
+  SELECT create_reference_table('reference_table_2');
+
+  -- now defining another foreign key would convert local tables to
+  -- citus local tables as reference_table_2 is now a reference table
+  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_12 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1);
+
+  -- now print metadata to show that everyting is fine
+  SELECT logicalrelid::text AS tablename, partmethod, repmodel FROM pg_dist_partition
+  WHERE logicalrelid::text IN (SELECT tablename FROM pg_tables WHERE schemaname='fkeys_between_local_ref')
+  ORDER BY tablename;
+ROLLBACK;
+
+-- we don't support foreign keys from citus local to reference tables
+-- with ON DELETE/UPDATE CASCADE behavior, so below two errors out
+
+BEGIN;
+  SELECT create_reference_table('reference_table_2');
+  ALTER TABLE reference_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES local_table_2(col_1) ON DELETE CASCADE;
+ROLLBACK;
+
+BEGIN;
+  SELECT create_reference_table('reference_table_2');
+  ALTER TABLE reference_table_2 ADD CONSTRAINT fkey_local_to_ref FOREIGN KEY (col_1) REFERENCES local_table_2(col_1) ON UPDATE CASCADE;
+ROLLBACK;
+
+-- but we support such foreign key behaviors when foreign key is from
+-- citus local to reference table
+
+BEGIN;
+  SELECT create_reference_table('reference_table_2');
+  ALTER TABLE local_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1) ON DELETE CASCADE;
+
+  DELETE FROM reference_table_2 WHERE col_1=200;
+  -- we deleted one row as DELETE cascades, so we should have 10 rows
+  SELECT COUNT(*) FROM local_table_2;
+ROLLBACK;
+
+BEGIN;
+  SELECT create_reference_table('reference_table_2');
+  ALTER TABLE local_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1) ON UPDATE CASCADE;
+ROLLBACK;
+
+-- cleanup at exit
+DROP SCHEMA fkeys_between_local_ref CASCADE;