Implement "citus local table" creation logic and a udf

src/backend/distributed/commands/create_citus_local_table.c

@@ -38,9 +38,6 @@
 
 static void ErrorIfUnsupportedCreateCitusLocalTable(Relation relation);
 static void ErrorIfUnsupportedCitusLocalTableKind(Oid relationId);
-static void ErrorIfRelationIsAKnownShard(Oid relationId);
-static void ErrorIfTableHasExternalForeignKeys(Oid relationId);
-static void ErrorIfCoordinatorNotAddedAsWorkerNode(Oid relationId);
 static uint64 ConvertLocalTableToShard(Oid relationId);
 static void RenameRelationToShardRelation(Oid shellRelationId, uint64 shardId);
 static void RenameShardRelationConstraints(Oid shardRelationId, uint64 shardId);
@@ -104,7 +101,7 @@ ErrorIfUnsupportedCreateCitusLocalTable(Relation relation)
 
 	Oid relationId = relation->rd_id;
 
-	ErrorIfCoordinatorNotAddedAsWorkerNode(relationId);
+	ErrorIfCoordinatorNotAddedAsWorkerNode();
 	ErrorIfUnsupportedCitusLocalTableKind(relationId);
 	EnsureTableNotDistributed(relationId);
 
@@ -166,82 +163,6 @@ ErrorIfUnsupportedCitusLocalTableKind(Oid relationId)
 }
 
 
-/*
- * ErrorIfRelationIsAKnownShard errors out if the relation with relationId is
- * a shard relation relation.
- */
-static void
-ErrorIfRelationIsAKnownShard(Oid relationId)
-{
-	/* search the relation in all schemas */
-	bool onlySearchPath = false;
-	if (!RelationIsAKnownShard(relationId, onlySearchPath))
-	{
-		return;
-	}
-
-	const char *relationName = get_rel_name(relationId);
-
-	ereport(ERROR, (errmsg("cannot create citus local table as \"%s\" is a shard "
-						   "relation ", relationName)));
-}
-
-
-/*
- * ErrorIfTableHasExternalForeignKeys errors out if the relation with relationId
- * is involved in a foreign key relationship other than the self-referencing ones.
- */
-static void
-ErrorIfTableHasExternalForeignKeys(Oid relationId)
-{
-	int flags = (INCLUDE_REFERENCING_CONSTRAINTS | EXCLUDE_SELF_REFERENCES);
-	List *foreignKeyIdsTableReferencing = GetForeignKeyOids(relationId, flags);
-
-	flags = (INCLUDE_REFERENCED_CONSTRAINTS | EXCLUDE_SELF_REFERENCES);
-	List *foreignKeyIdsTableReferenced = GetForeignKeyOids(relationId, flags);
-
-	List *foreignKeysWithOtherTables = list_concat(foreignKeyIdsTableReferencing,
-												   foreignKeyIdsTableReferenced);
-
-	if (list_length(foreignKeysWithOtherTables) == 0)
-	{
-		return;
-	}
-
-	const char *relationName = get_rel_name(relationId);
-
-	ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					errmsg("cannot create citus local table \"%s\", citus local "
-						   "tables cannot be involved in foreign key relationships "
-						   "with other tables initially", relationName),
-					errhint("Drop foreign keys with other tables and re-define them "
-							"with ALTER TABLE commands after creating the table.")));
-}
-
-
-/*
- * ErrorIfCoordinatorNotAddedAsWorkerNode error out if coordinator is not added
- * to metadata.
- */
-static void
-ErrorIfCoordinatorNotAddedAsWorkerNode(Oid relationId)
-{
-	if (CoordinatorAddedAsWorkerNode())
-	{
-		return;
-	}
-
-	const char *relationName = get_rel_name(relationId);
-
-	ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-					errmsg("cannot create citus local table \"%s\", citus local "
-						   "tables can only be created from coordinator node if "
-						   "it is added as a worker node", relationName),
-					errhint("First, add the coordinator with master_add_node "
-							"command")));
-}
-
-
 /*
  * CreateCitusLocalTable is the internal method that creates a citus table
  * from the table with relationId. The created table would have the following

src/backend/distributed/commands/foreign_constraint.c

@@ -649,6 +649,37 @@ FindForeignKeyOidWithName(List *foreignKeyOids, const char *inputConstraintName)
 }
 
 
+/*
+ * ErrorIfTableHasExternalForeignKeys errors out if the relation with relationId
+ * is involved in a foreign key relationship other than the self-referencing ones.
+ */
+void
+ErrorIfTableHasExternalForeignKeys(Oid relationId)
+{
+	int flags = (INCLUDE_REFERENCING_CONSTRAINTS | EXCLUDE_SELF_REFERENCES);
+	List *foreignKeyIdsTableReferencing = GetForeignKeyOids(relationId, flags);
+
+	flags = (INCLUDE_REFERENCED_CONSTRAINTS | EXCLUDE_SELF_REFERENCES);
+	List *foreignKeyIdsTableReferenced = GetForeignKeyOids(relationId, flags);
+
+	List *foreignKeysWithOtherTables = list_concat(foreignKeyIdsTableReferencing,
+												   foreignKeyIdsTableReferenced);
+
+	if (list_length(foreignKeysWithOtherTables) == 0)
+	{
+		return;
+	}
+
+	const char *relationName = get_rel_name(relationId);
+	ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					errmsg("relation \"%s\" is involved in a foreign key relationship "
+						   "with another table", relationName),
+					errhint("Drop foreign keys with other tables and re-define them "
+							"with ALTER TABLE commands after the current operation "
+							"is done.")));
+}
+
+
 /*
  * GetForeignKeyOids takes in a relationId, and returns a list of OIDs for
  * foreign constraints that the relation with relationId is involved according

src/backend/distributed/operations/worker_node_manager.c

@@ -445,11 +445,7 @@ ReferenceTablePlacementNodeList(LOCKMODE lockMode)
 WorkerNode *
 CoordinatorNode()
 {
-	if (!CoordinatorAddedAsWorkerNode())
-	{
-		ereport(ERROR, (errmsg("couldn't find the coordinator node in the metadata "
-							   "as it is not added as a worker")));
-	}
+	ErrorIfCoordinatorNotAddedAsWorkerNode();
 
 	WorkerNode *coordinatorNode = LookupNodeForGroup(COORDINATOR_GROUP_ID);
 
@@ -460,6 +456,23 @@ CoordinatorNode()
 }
 
 
+/*
+ * ErrorIfCoordinatorNotAddedAsWorkerNode errors out if coordinator is not added
+ * to metadata.
+ */
+void
+ErrorIfCoordinatorNotAddedAsWorkerNode()
+{
+	if (CoordinatorAddedAsWorkerNode())
+	{
+		return;
+	}
+
+	ereport(ERROR, (errmsg("could not find the coordinator node in "
+						   "metadata as it is not added as a worker")));
+}
+
+
 /*
  * DistributedTablePlacementNodeList returns a list of all active, primary
  * worker nodes that can store new data, i.e shouldstoreshards is 'true'

src/backend/distributed/worker/worker_shard_visibility.c

@@ -97,6 +97,25 @@ citus_table_is_visible(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * ErrorIfRelationIsAKnownShard errors out if the relation with relationId is
+ * a shard relation.
+ */
+void
+ErrorIfRelationIsAKnownShard(Oid relationId)
+{
+	/* search the relation in all schemas */
+	bool onlySearchPath = false;
+	if (!RelationIsAKnownShard(relationId, onlySearchPath))
+	{
+		return;
+	}
+
+	const char *relationName = get_rel_name(relationId);
+	ereport(ERROR, (errmsg("relation \"%s\" is a shard relation ", relationName)));
+}
+
+
 /*
  * RelationIsAKnownShard gets a relationId, check whether it's a shard of
  * any distributed table. If onlySearchPath is true, then it searches

src/include/distributed/commands.h

@@ -124,6 +124,7 @@ extern bool HasForeignKeyToReferenceTable(Oid relationOid);
 extern bool TableReferenced(Oid relationOid);
 extern bool TableReferencing(Oid relationOid);
 extern bool ConstraintIsAForeignKey(char *inputConstaintName, Oid relationOid);
+extern void ErrorIfTableHasExternalForeignKeys(Oid relationId);
 extern List * GetForeignKeyOids(Oid relationId, int flags);
 
 

src/include/distributed/worker_manager.h

@@ -76,6 +76,7 @@ extern List * ActivePrimaryNodeList(LOCKMODE lockMode);
 extern bool CoordinatorAddedAsWorkerNode(void);
 extern List * ReferenceTablePlacementNodeList(LOCKMODE lockMode);
 extern WorkerNode * CoordinatorNode(void);
+extern void ErrorIfCoordinatorNotAddedAsWorkerNode(void);
 extern List * DistributedTablePlacementNodeList(LOCKMODE lockMode);
 extern bool NodeCanHaveDistTablePlacements(WorkerNode *node);
 extern uint32 ActiveReadableWorkerNodeCount(void);

src/include/distributed/worker_shard_visibility.h

@@ -17,6 +17,7 @@ extern bool OverrideTableVisibility;
 
 
 extern void ReplaceTableVisibleFunction(Node *inputNode);
+extern void ErrorIfRelationIsAKnownShard(Oid relationId);
 extern bool RelationIsAKnownShard(Oid shardRelationId, bool onlySearchPath);
 
 

src/test/regress/bin/normalize.sed

@@ -35,7 +35,7 @@ s/ keyval(1|2|ref)_[0-9]+ / keyval\1_xxxxxxx /g
 s/ daily_uniques_[0-9]+ / daily_uniques_xxxxxxx /g
 
 # shard table names for isolation_create_citus_local_table
-s/ "citus_local_table_[0-9]_[0-9]+" / "citus_local_table_[0-9]_xxxxxxx" /g
+s/ "citus_local_table_[0-9]+_[0-9]+" / "citus_local_table_[0-9]+_xxxxxxx" /g
 
 # In foreign_key_restriction_enforcement, normalize shard names
 s/"(on_update_fkey_table_|fkey_)[0-9]+"/"\1xxxxxxx"/g

src/test/regress/expected/citus_local_tables.out

@@ -40,7 +40,7 @@ SELECT 1 FROM master_remove_node('localhost', :master_port);
 CREATE TABLE citus_local_table_1 (a int primary key);
 -- this should fail as coordinator is removed from pg_dist_node
 SELECT create_citus_local_table('citus_local_table_1');
-ERROR:  cannot create citus local table "citus_local_table_1", citus local tables can only be created from coordinator node if it is added as a worker node
+ERROR:  could not find the coordinator node in metadata as it is not added as a worker
 -- let coordinator have citus local tables again for next tests
 set client_min_messages to ERROR;
 SELECT 1 FROM master_add_node('localhost', :master_port, groupId => 0);
@@ -96,32 +96,28 @@ SELECT create_citus_local_table('citus_local_table_2');
 (1 row)
 
 CREATE TABLE distributed_table (a int);
--- cannot create citus local table from an existing citus table
 SELECT create_distributed_table('distributed_table', 'a');
  create_distributed_table
 ---------------------------------------------------------------------
 
 (1 row)
 
--- this will error out
+-- cannot create citus local table from an existing citus table
 SELECT create_citus_local_table('distributed_table');
 ERROR:  table "distributed_table" is already distributed
--- partitiond table tests --
+-- partitioned table tests --
 CREATE TABLE partitioned_table(a int, b int) PARTITION BY RANGE (a);
 CREATE TABLE partitioned_table_1 PARTITION OF partitioned_table FOR VALUES FROM (0) TO (10);
 CREATE TABLE partitioned_table_2 PARTITION OF partitioned_table FOR VALUES FROM (10) TO (20);
 -- cannot create partitioned citus local tables
 SELECT create_citus_local_table('partitioned_table');
 ERROR:  cannot create citus local table "partitioned_table", only regular tables and foreign tables are supported for citus local table creation
--- cannot create citus local table as a partition of a local table
 BEGIN;
   CREATE TABLE citus_local_table PARTITION OF partitioned_table FOR VALUES FROM (20) TO (30);
-  -- this should fail
+  -- cannot create citus local table as a partition of a local table
   SELECT create_citus_local_table('citus_local_table');
 ERROR:  cannot create citus local table "citus_local_table", citus local tables cannot be partition of other tables
 ROLLBACK;
--- cannot create citus local table as a partition of a local table
--- via ALTER TABLE commands as well
 BEGIN;
   CREATE TABLE citus_local_table (a int, b int);
   SELECT create_citus_local_table('citus_local_table');
@@ -130,11 +126,11 @@ BEGIN;
 
 (1 row)
 
-  -- this should fail
+  -- cannot create citus local table as a partition of a local table
+  -- via ALTER TABLE commands as well
   ALTER TABLE partitioned_table ATTACH PARTITION citus_local_table FOR VALUES FROM (20) TO (30);
 ERROR:  non-distributed tables cannot have distributed partitions
 ROLLBACK;
--- cannot attach citus local table to a partitioned distributed table
 BEGIN;
   SELECT create_distributed_table('partitioned_table', 'a');
  create_distributed_table
@@ -149,7 +145,7 @@ BEGIN;
 
 (1 row)
 
-  -- this should fail
+  -- cannot attach citus local table to a partitioned distributed table
   ALTER TABLE partitioned_table ATTACH PARTITION citus_local_table FOR VALUES FROM (20) TO (30);
 ERROR:  distributed tables cannot have non-colocated distributed tables as a partition
 ROLLBACK;
@@ -318,9 +314,9 @@ CREATE TABLE local_table_3 (a int primary key, b int references local_table_3(a)
 -- below two should fail as we do not allow foreign keys between
 -- postgres local tables and citus local tables
 SELECT create_citus_local_table('local_table_1');
-ERROR:  cannot create citus local table "local_table_1", citus local tables cannot be involved in foreign key relationships with other tables initially
+ERROR:  relation "local_table_1" is involved in a foreign key relationship with another table
 SELECT create_citus_local_table('local_table_2');
-ERROR:  cannot create citus local table "local_table_2", citus local tables cannot be involved in foreign key relationships with other tables initially
+ERROR:  relation "local_table_2" is involved in a foreign key relationship with another table
 -- below should work as we allow initial self references in citus local tables
 SELECT create_citus_local_table('local_table_3');
  create_citus_local_table

src/test/regress/expected/isolation_create_citus_local_table.out

@@ -10,7 +10,7 @@ create_citus_local_table
 step s2-create-citus-local-table-1: SELECT create_citus_local_table('citus_local_table_1'); <waiting ...>
 step s1-commit: COMMIT;
 step s2-create-citus-local-table-1: <... completed>
-error in steps s1-commit s2-create-citus-local-table-1: ERROR:  cannot create citus local table as "citus_local_table_[0-9]_xxxxxxx" is a shard relation
+error in steps s1-commit s2-create-citus-local-table-1: ERROR:  relation "citus_local_table_[0-9]+_xxxxxxx" is a shard relation
 step s2-commit: COMMIT;
 master_remove_node
 
@@ -26,7 +26,7 @@ create_citus_local_table
 step s2-create-citus-local-table-3: SELECT create_citus_local_table('another_schema.citus_local_table_3'); <waiting ...>
 step s1-commit: COMMIT;
 step s2-create-citus-local-table-3: <... completed>
-error in steps s1-commit s2-create-citus-local-table-3: ERROR:  cannot create citus local table as "citus_local_table_[0-9]_xxxxxxx" is a shard relation
+error in steps s1-commit s2-create-citus-local-table-3: ERROR:  relation "citus_local_table_[0-9]+_xxxxxxx" is a shard relation
 step s2-commit: COMMIT;
 master_remove_node
 
@@ -187,7 +187,7 @@ master_remove_node
 step s2-create-citus-local-table-1: SELECT create_citus_local_table('citus_local_table_1'); <waiting ...>
 step s1-commit: COMMIT;
 step s2-create-citus-local-table-1: <... completed>
-error in steps s1-commit s2-create-citus-local-table-1: ERROR:  cannot create citus local table "citus_local_table_1", citus local tables can only be created from coordinator node if it is added as a worker node
+error in steps s1-commit s2-create-citus-local-table-1: ERROR:  could not find the coordinator node in metadata as it is not added as a worker
 step s2-commit: COMMIT;
 master_remove_node
 

src/test/regress/spec/isolation_create_citus_local_table.spec

@@ -46,7 +46,7 @@ step "s2-rollback" { ROLLBACK; }
 
 // create_citus_local_table vs command/query //
 
-// Second session should error out as the table become a citus local table after the first session commits ..
+// Second session should error out as the table becomes a citus local table after the first session commits ..
 permutation "s1-begin" "s2-begin" "s1-create-citus-local-table-1" "s2-create-citus-local-table-1" "s1-commit" "s2-commit"
 // .. and it should error out even if we are in a different schema than the table
 permutation "s1-begin" "s2-begin" "s1-create-citus-local-table-3" "s2-create-citus-local-table-3" "s1-commit" "s2-commit"