Update the places where we check circular dependency

src/backend/distributed/commands/dependencies.c

@@ -31,7 +31,6 @@
 
 typedef bool (*AddressPredicate)(const ObjectAddress *);
 
-static void ErrorIfCircularDependencyExists(const ObjectAddress *objectAddress);
 static int ObjectAddressComparator(const void *a, const void *b);
 static List * GetDependencyCreateDDLCommands(const ObjectAddress *dependency);
 static List * FilterObjectAddressListByPredicate(List *objectAddressList,
@@ -57,13 +56,6 @@ EnsureDependenciesExistOnAllNodes(const ObjectAddress *target)
 	List *dependenciesWithCommands = NIL;
 	List *ddlCommands = NULL;
 
-	/*
-	 * Having circular dependency between distributed objects prevents Citus from
-	 * adding a new node. So, error out if circular dependency exists for the given
-	 * target object.
-	 */
-	ErrorIfCircularDependencyExists(target);
-
 	/* collect all dependencies in creation order and get their ddl commands */
 	List *dependencies = GetDependenciesForObject(target);
 	ObjectAddress *dependency = NULL;
@@ -143,40 +135,6 @@ EnsureDependenciesExistOnAllNodes(const ObjectAddress *target)
 }
 
 
-/*
- * ErrorIfCircularDependencyExists checks whether given object has circular dependency
- * with itself via existing objects of pg_dist_object.
- */
-static void
-ErrorIfCircularDependencyExists(const ObjectAddress *objectAddress)
-{
-	List *dependencies = GetAllSupportedDependenciesForObject(objectAddress);
-
-	ObjectAddress *dependency = NULL;
-	foreach_ptr(dependency, dependencies)
-	{
-		if (dependency->classId == objectAddress->classId &&
-			dependency->objectId == objectAddress->objectId &&
-			dependency->objectSubId == objectAddress->objectSubId)
-		{
-			char *objectDescription = NULL;
-
-			#if PG_VERSION_NUM >= PG_VERSION_14
-			objectDescription = getObjectDescription(objectAddress, false);
-			#else
-			objectDescription = getObjectDescription(objectAddress);
-			#endif
-
-			ereport(ERROR, (errmsg("Citus can not handle circular dependencies "
-								   "between distributed objects"),
-							errdetail("\"%s\" circularly depends itself, resolve "
-									  "circular dependency first",
-									  objectDescription)));
-		}
-	}
-}
-
-
 /*
  * Copied from PG object_address_comparator function to compare ObjectAddresses.
  */

src/backend/distributed/commands/utility_hook.c

@@ -58,6 +58,7 @@
 #include "distributed/metadata_cache.h"
 #endif
 #include "distributed/metadata_sync.h"
+#include "distributed/metadata/dependency.h"
 #include "distributed/metadata/distobject.h"
 #include "distributed/multi_executor.h"
 #include "distributed/multi_explain.h"
@@ -656,6 +657,18 @@ ProcessUtilityInternal(PlannedStmt *pstmt,
 	 */
 	if (EnableDDLPropagation)
 	{
+		/*
+		 * Having circular dependency between distributed objects prevents Citus from
+		 * adding a new node. So, error out if circular dependency exists for the given
+		 * target object.
+		 *
+		 * We need to check circular dependency here in addition to checking it within
+		 * MarkObjectDistributedLocally since altering already distributed object won't
+		 * call MarkObjectDistributedLocally but will hit the check here.
+		 */
+		ObjectAddress targetObject = GetObjectAddressFromParseTree(parsetree, false);
+		ErrorIfCircularDependencyExists(&targetObject);
+
 		if (ops && ops->postprocess)
 		{
 			List *processJobs = ops->postprocess(parsetree, queryString);

src/backend/distributed/metadata/dependency.c

@@ -378,6 +378,40 @@ RecurseObjectDependencies(ObjectAddress target, expandFn expand, followFn follow
 }
 
 
+/*
+ * ErrorIfCircularDependencyExists checks whether given object has circular dependency
+ * with itself via existing objects of pg_dist_object.
+ */
+void
+ErrorIfCircularDependencyExists(const ObjectAddress *objectAddress)
+{
+	List *dependencies = GetAllSupportedDependenciesForObject(objectAddress);
+
+	ObjectAddress *dependency = NULL;
+	foreach_ptr(dependency, dependencies)
+	{
+		if (dependency->classId == objectAddress->classId &&
+			dependency->objectId == objectAddress->objectId &&
+			dependency->objectSubId == objectAddress->objectSubId)
+		{
+			char *objectDescription = NULL;
+
+			#if PG_VERSION_NUM >= PG_VERSION_14
+			objectDescription = getObjectDescription(objectAddress, false);
+			#else
+			objectDescription = getObjectDescription(objectAddress);
+			#endif
+
+			ereport(ERROR, (errmsg("Citus can not handle circular dependencies "
+								   "between distributed objects"),
+							errdetail("\"%s\" circularly depends itself, resolve "
+									  "circular dependency first",
+									  objectDescription)));
+		}
+	}
+}
+
+
 /*
  * DependencyDefinitionFromPgDepend loads all pg_depend records describing the
  * dependencies of target.

src/backend/distributed/metadata/distobject.c

@@ -30,6 +30,7 @@
 #include "commands/extension.h"
 #include "distributed/colocation_utils.h"
 #include "distributed/commands/utility_hook.h"
+#include "distributed/metadata/dependency.h"
 #include "distributed/metadata/distobject.h"
 #include "distributed/metadata/pg_dist_object.h"
 #include "distributed/metadata_cache.h"
@@ -198,6 +199,16 @@ MarkObjectDistributedViaSuperUser(const ObjectAddress *distAddress)
 static void
 MarkObjectDistributedLocally(const ObjectAddress *distAddress)
 {
+	/*
+	 * Having circular dependency between distributed objects prevents Citus from
+	 * adding a new node. So, error out if circular dependency exists for the given
+	 * target object.
+	 *
+	 * Similar check also added to postprocess phase of ProcessUtilityInternal to
+	 * handle altering already distributed objects.
+	 */
+	ErrorIfCircularDependencyExists(distAddress);
+
 	int paramCount = 3;
 	Oid paramTypes[3] = {
 		OIDOID,

src/include/distributed/metadata/dependency.h

@@ -24,6 +24,7 @@ extern List * GetAllDependenciesForObject(const ObjectAddress *target);
 extern void EnsureRelationDependenciesCanBeDistributed(ObjectAddress *relationAddress);
 extern ObjectAddress * GetUndistributableDependency(ObjectAddress *target);
 extern List * OrderObjectAddressListInDependencyOrder(List *objectAddressList);
+extern void ErrorIfCircularDependencyExists(const ObjectAddress *objectAddress);
 extern bool SupportedDependencyByCitus(const ObjectAddress *address);
 extern List * GetPgDependTuplesForDependingObjects(Oid targetObjectClassId,
 												   Oid targetObjectId);