citusdata · eaydingol · Feb 18, 2026 · Feb 19, 2026 · Feb 19, 2026 · Feb 19, 2026
diff --git a/src/backend/distributed/commands/table.c b/src/backend/distributed/commands/table.c
diff --git a/src/backend/distributed/commands/utility_hook.c b/src/backend/distributed/commands/utility_hook.c
@@ -349,8 +349,24 @@ citus_ProcessUtility(PlannedStmt *pstmt,
 
 	PG_TRY();
 	{
-		citus_ProcessUtilityInternal(pstmt, queryString, context, params, queryEnv, dest,
-									 completionTag);
+		/*
+		 * For CREATE TABLE AS SELECT with auto-distribution enabled,
+		 * try the optimized path that avoids pulling data through the
+		 * coordinator. If successful, skip normal CTAS processing.
+		 */
+		bool ctasHandled = false;
+		if (context == PROCESS_UTILITY_TOPLEVEL &&
+			IsA(parsetree, CreateTableAsStmt))
+		{
+			ctasHandled = TryOptimizeCTASForAutoDistribution(
+				(CreateTableAsStmt *) parsetree, queryString);
+		}
+
+		if (!ctasHandled)
+		{
+			citus_ProcessUtilityInternal(pstmt, queryString, context, params,
+										 queryEnv, dest, completionTag);
+		}
 
 		if (UtilityHookLevel == 1)
 		{
@@ -370,6 +386,7 @@ citus_ProcessUtility(PlannedStmt *pstmt,
 			 * to create a tenant schema table or a Citus managed table.
 			 */
 			if (context == PROCESS_UTILITY_TOPLEVEL &&
+				!ctasHandled &&
 				(IsA(parsetree, CreateStmt) ||
 				 IsA(parsetree, CreateForeignTableStmt) ||
 				 IsA(parsetree, CreateTableAsStmt)))

diff --git a/src/backend/distributed/shared_library_init.c b/src/backend/distributed/shared_library_init.c
@@ -1251,6 +1251,21 @@ RegisterCitusConfigVariables(void)
 		GUC_STANDARD,
 		ErrorIfNotASuitableDeadlockFactor, NULL, NULL);
 
+	DefineCustomStringVariable(
+		"citus.distribution_columns",
+		gettext_noop("Sets a priority list of distribution columns for new tables."),
+		gettext_noop("A comma-separated list of column names in priority order "
+					 "(e.g. 'tenant_id,customer_id,department'). When a new table "
+					 "is created, Citus walks the list in order and distributes "
+					 "the table by the first column name that exists in the table. "
+					 "Applies to CREATE TABLE and CREATE TABLE AS SELECT. "
+					 "Set to empty string to disable."),
+		&DistributionColumns,
+		"",
+		PGC_USERSET,
+		GUC_STANDARD,
+		CheckDistributionColumns, AssignDistributionColumns, NULL);
+
 	DefineCustomBoolVariable(
 		"citus.enable_alter_database_owner",
 		gettext_noop("Enables propagating ALTER DATABASE ... OWNER TO ... statements to "

diff --git a/src/include/distributed/commands.h b/src/include/distributed/commands.h
@@ -26,6 +26,11 @@
 
 extern bool AddAllLocalTablesToMetadata;
 extern bool EnableSchemaBasedSharding;
+extern char *DistributionColumns;
+extern List *ParsedDistributionColumns;
+
+extern bool CheckDistributionColumns(char **newval, void **extra, GucSource source);
+extern void AssignDistributionColumns(const char *newval, void *extra);
 
 /* controlled via GUC, should be accessed via EnableLocalReferenceForeignKeys() */
 extern bool EnableLocalReferenceForeignKeys;
@@ -669,6 +674,8 @@ extern char * GetAlterColumnWithNextvalDefaultCmd(Oid sequenceOid, Oid relationI
 												  char *colname, bool missingTableOk);
 
 extern void ErrorIfTableHasIdentityColumn(Oid relationId);
+extern bool TryOptimizeCTASForAutoDistribution(CreateTableAsStmt *ctasStmt,
+												const char *queryString);
 extern void ConvertNewTableIfNecessary(Node *createStmt);
 extern void ConvertToTenantTableIfNecessary(AlterObjectSchemaStmt *alterObjectSchemaStmt);
 

diff --git a/src/test/regress/Makefile b/src/test/regress/Makefile
@@ -56,7 +56,7 @@ vanilla_diffs_file = $(citus_abs_srcdir)/pg_vanilla_outputs/$(MAJORVERSION)/regr
 # intermediate, for muscle memory backward compatibility.
 check: check-full check-enterprise-full
 # check-full triggers all tests that ought to be run routinely
-check-full: check-multi check-multi-mx check-multi-1 check-multi-1-create-citus check-operations check-add-backup-node check-follower-cluster check-isolation check-failure check-split check-vanilla check-columnar check-columnar-isolation check-pg-upgrade check-arbitrary-configs check-citus-upgrade check-citus-upgrade-mixed check-citus-upgrade-local check-citus-upgrade-mixed-local check-pytest check-query-generator check-tap
+check-full: check-multi check-multi-mx check-multi-1 check-multi-1-create-citus check-post-citus14 check-operations check-add-backup-node check-follower-cluster check-isolation check-failure check-split check-vanilla check-columnar check-columnar-isolation check-pg-upgrade check-arbitrary-configs check-citus-upgrade check-citus-upgrade-mixed check-citus-upgrade-local check-citus-upgrade-mixed-local check-pytest check-query-generator check-tap
 # check-enterprise-full triggers all enterprise specific tests
 check-enterprise-full: check-enterprise check-enterprise-isolation check-enterprise-failure check-enterprise-isolation-logicalrep-1 check-enterprise-isolation-logicalrep-2 check-enterprise-isolation-logicalrep-3
 
@@ -173,6 +173,10 @@ check-multi-1: all
 	$(pg_regress_multi_check) --load-extension=citus \
 	-- $(MULTI_REGRESS_OPTS) --schedule=$(citus_abs_srcdir)/multi_1_schedule $(EXTRA_TESTS)
 
+check-post-citus14: all
+	$(pg_regress_multi_check) --load-extension=citus \
+	-- $(MULTI_REGRESS_OPTS) --schedule=$(citus_abs_srcdir)/post_citus14_schedule $(EXTRA_TESTS)
+
 check-multi-1-create-citus: all
 	$(pg_regress_multi_check) --load-extension=citus \
 	-- $(MULTI_REGRESS_OPTS) --schedule=$(citus_abs_srcdir)/multi_1_create_citus_schedule $(EXTRA_TESTS)