Move 2 functions to correct files (#7000)

Followup item from
https://github.com/citusdata/citus/pull/6933#discussion_r1217896933

src/backend/distributed/commands/alter_table.c

@@ -361,6 +361,43 @@ worker_change_sequence_dependency(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * DropFKeysAndUndistributeTable drops all foreign keys that relation with
+ * relationId is involved then undistributes it.
+ * Note that as UndistributeTable changes relationId of relation, this
+ * function also returns new relationId of relation.
+ * Also note that callers are responsible for storing & recreating foreign
+ * keys to be dropped if needed.
+ */
+Oid
+DropFKeysAndUndistributeTable(Oid relationId)
+{
+	DropFKeysRelationInvolvedWithTableType(relationId, INCLUDE_ALL_TABLE_TYPES);
+
+	/* store them before calling UndistributeTable as it changes relationId */
+	char *relationName = get_rel_name(relationId);
+	Oid schemaId = get_rel_namespace(relationId);
+
+	/* suppress notices messages not to be too verbose */
+	TableConversionParameters params = {
+		.relationId = relationId,
+		.cascadeViaForeignKeys = false,
+		.suppressNoticeMessages = true
+	};
+	UndistributeTable(&params);
+
+	Oid newRelationId = get_relname_relid(relationName, schemaId);
+
+	/*
+	 * We don't expect this to happen but to be on the safe side let's error
+	 * out here.
+	 */
+	EnsureRelationExists(newRelationId);
+
+	return newRelationId;
+}
+
+
 /*
  * UndistributeTables undistributes given relations. It first collects all foreign keys
  * to recreate them after the undistribution. Then, drops the foreign keys and

src/backend/distributed/commands/create_distributed_table.c

@@ -1571,85 +1571,6 @@ EnsureDistributedSequencesHaveOneType(Oid relationId, List *seqInfoList)
 }
 
 
-/*
- * GetFKeyCreationCommandsRelationInvolvedWithTableType returns a list of DDL
- * commands to recreate the foreign keys that relation with relationId is involved
- * with given table type.
- */
-List *
-GetFKeyCreationCommandsRelationInvolvedWithTableType(Oid relationId, int tableTypeFlag)
-{
-	int referencingFKeysFlag = INCLUDE_REFERENCING_CONSTRAINTS |
-							   tableTypeFlag;
-	List *referencingFKeyCreationCommands =
-		GetForeignConstraintCommandsInternal(relationId, referencingFKeysFlag);
-
-	/* already captured self referencing foreign keys, so use EXCLUDE_SELF_REFERENCES */
-	int referencedFKeysFlag = INCLUDE_REFERENCED_CONSTRAINTS |
-							  EXCLUDE_SELF_REFERENCES |
-							  tableTypeFlag;
-	List *referencedFKeyCreationCommands =
-		GetForeignConstraintCommandsInternal(relationId, referencedFKeysFlag);
-	return list_concat(referencingFKeyCreationCommands, referencedFKeyCreationCommands);
-}
-
-
-/*
- * DropFKeysAndUndistributeTable drops all foreign keys that relation with
- * relationId is involved then undistributes it.
- * Note that as UndistributeTable changes relationId of relation, this
- * function also returns new relationId of relation.
- * Also note that callers are responsible for storing & recreating foreign
- * keys to be dropped if needed.
- */
-Oid
-DropFKeysAndUndistributeTable(Oid relationId)
-{
-	DropFKeysRelationInvolvedWithTableType(relationId, INCLUDE_ALL_TABLE_TYPES);
-
-	/* store them before calling UndistributeTable as it changes relationId */
-	char *relationName = get_rel_name(relationId);
-	Oid schemaId = get_rel_namespace(relationId);
-
-	/* suppress notices messages not to be too verbose */
-	TableConversionParameters params = {
-		.relationId = relationId,
-		.cascadeViaForeignKeys = false,
-		.suppressNoticeMessages = true
-	};
-	UndistributeTable(&params);
-
-	Oid newRelationId = get_relname_relid(relationName, schemaId);
-
-	/*
-	 * We don't expect this to happen but to be on the safe side let's error
-	 * out here.
-	 */
-	EnsureRelationExists(newRelationId);
-
-	return newRelationId;
-}
-
-
-/*
- * DropFKeysRelationInvolvedWithTableType drops foreign keys that relation
- * with relationId is involved with given table type.
- */
-void
-DropFKeysRelationInvolvedWithTableType(Oid relationId, int tableTypeFlag)
-{
-	int referencingFKeysFlag = INCLUDE_REFERENCING_CONSTRAINTS |
-							   tableTypeFlag;
-	DropRelationForeignKeys(relationId, referencingFKeysFlag);
-
-	/* already captured self referencing foreign keys, so use EXCLUDE_SELF_REFERENCES */
-	int referencedFKeysFlag = INCLUDE_REFERENCED_CONSTRAINTS |
-							  EXCLUDE_SELF_REFERENCES |
-							  tableTypeFlag;
-	DropRelationForeignKeys(relationId, referencedFKeysFlag);
-}
-
-
 /*
  * DecideDistTableReplicationModel function decides which replication model should be
  * used for a distributed table depending on given distribution configuration.

src/backend/distributed/commands/foreign_constraint.c

@@ -896,6 +896,48 @@ GetForeignConstraintCommandsInternal(Oid relationId, int flags)
 }
 
 
+/*
+ * GetFKeyCreationCommandsRelationInvolvedWithTableType returns a list of DDL
+ * commands to recreate the foreign keys that relation with relationId is involved
+ * with given table type.
+ */
+List *
+GetFKeyCreationCommandsRelationInvolvedWithTableType(Oid relationId, int tableTypeFlag)
+{
+	int referencingFKeysFlag = INCLUDE_REFERENCING_CONSTRAINTS |
+							   tableTypeFlag;
+	List *referencingFKeyCreationCommands =
+		GetForeignConstraintCommandsInternal(relationId, referencingFKeysFlag);
+
+	/* already captured self referencing foreign keys, so use EXCLUDE_SELF_REFERENCES */
+	int referencedFKeysFlag = INCLUDE_REFERENCED_CONSTRAINTS |
+							  EXCLUDE_SELF_REFERENCES |
+							  tableTypeFlag;
+	List *referencedFKeyCreationCommands =
+		GetForeignConstraintCommandsInternal(relationId, referencedFKeysFlag);
+	return list_concat(referencingFKeyCreationCommands, referencedFKeyCreationCommands);
+}
+
+
+/*
+ * DropFKeysRelationInvolvedWithTableType drops foreign keys that relation
+ * with relationId is involved with given table type.
+ */
+void
+DropFKeysRelationInvolvedWithTableType(Oid relationId, int tableTypeFlag)
+{
+	int referencingFKeysFlag = INCLUDE_REFERENCING_CONSTRAINTS |
+							   tableTypeFlag;
+	DropRelationForeignKeys(relationId, referencingFKeysFlag);
+
+	/* already captured self referencing foreign keys, so use EXCLUDE_SELF_REFERENCES */
+	int referencedFKeysFlag = INCLUDE_REFERENCED_CONSTRAINTS |
+							  EXCLUDE_SELF_REFERENCES |
+							  tableTypeFlag;
+	DropRelationForeignKeys(relationId, referencedFKeysFlag);
+}
+
+
 /*
  * HasForeignKeyWithLocalTable returns true if relation has foreign key
  * relationship with a local table.