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Skip postgres tables for UndistributeTable(cascadeViaFKeys) (#4530) 

The reason behind skipping postgres tables is that we support
foreign keys between postgres tables and reference tables
(without converting postgres tables to citus local tables)
when enable_local_reference_table_foreign_keys is false or
when coordinator is not added to metadata.
pull/4528/head^2
Onur Tirtir 2021-01-17 20:32:30 +03:00 committed by GitHub
parent 2e61f93171
commit 5a3e8a6e24
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3 changed files with 64 additions and 15 deletions
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21
src/backend/distributed/commands/cascade_table_operation_for_connected_relations.c
View File

@ -353,19 +353,28 @@ ExecuteCascadeOperationForRelationIdList(List *relationIdList,
foreach_oid(relationId, relationIdList)
{
/*
* Caller already passed the relations that we should operate on,
* so we should not cascade here.
* The reason behind skipping certain table types in below loop is
* that we support some sort of foreign keys between postgres tables
* and citus tables when enable_local_reference_table_foreign_keys is
* false or when coordinator is not added to metadata.
*
* Also, as caller already passed the relations that we should operate
* on, we don't cascade via foreign keys here.
*/
bool cascadeViaForeignKeys = false;
switch (cascadeOperationType)
{
case CASCADE_FKEY_UNDISTRIBUTE_TABLE:
{
if (IsCitusTable(relationId))
{
TableConversionParameters params = {
.relationId = relationId,
.cascadeViaForeignKeys = cascadeViaForeignKeys
};
UndistributeTable(&params);
}
break;
}
@ -373,14 +382,6 @@ ExecuteCascadeOperationForRelationIdList(List *relationIdList,
{
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);
}

32
src/test/regress/expected/undistribute_table_cascade.out
View File

@ -4,6 +4,38 @@ SET citus.shard_replication_factor TO 1;
CREATE SCHEMA undistribute_table_cascade;
SET search_path TO undistribute_table_cascade;
SET client_min_messages to ERROR;
-- remove coordinator if it is added to pg_dist_node
SELECT COUNT(master_remove_node(nodename, nodeport)) < 2
FROM pg_dist_node WHERE nodename='localhost' AND nodeport=:master_port;
?column?
---------------------------------------------------------------------
t
(1 row)
BEGIN;
CREATE TABLE reference_table(col_1 INT UNIQUE);
CREATE TABLE distributed_table(col_1 INT UNIQUE);
CREATE TABLE local_table (col_1 INT REFERENCES reference_table(col_1), FOREIGN KEY (col_1) REFERENCES distributed_table(col_1));
SELECT create_reference_table('reference_table');
create_reference_table
---------------------------------------------------------------------
(1 row)
SELECT create_distributed_table('distributed_table', 'col_1');
create_distributed_table
---------------------------------------------------------------------
(1 row)
-- show that we skip postgres tables when undistributing citus tables
SELECT undistribute_table('reference_table', cascade_via_foreign_keys=>true);
undistribute_table
---------------------------------------------------------------------
(1 row)
ROLLBACK;
-- ensure that coordinator is added to pg_dist_node
SELECT 1 FROM master_add_node('localhost', :master_port, groupId => 0);
?column?

16
src/test/regress/sql/undistribute_table_cascade.sql
View File

@ -8,6 +8,22 @@ SET search_path TO undistribute_table_cascade;
SET client_min_messages to ERROR;
-- remove coordinator if it is added to pg_dist_node
SELECT COUNT(master_remove_node(nodename, nodeport)) < 2
FROM pg_dist_node WHERE nodename='localhost' AND nodeport=:master_port;
BEGIN;
CREATE TABLE reference_table(col_1 INT UNIQUE);
CREATE TABLE distributed_table(col_1 INT UNIQUE);
CREATE TABLE local_table (col_1 INT REFERENCES reference_table(col_1), FOREIGN KEY (col_1) REFERENCES distributed_table(col_1));
SELECT create_reference_table('reference_table');
SELECT create_distributed_table('distributed_table', 'col_1');
-- show that we skip postgres tables when undistributing citus tables
SELECT undistribute_table('reference_table', cascade_via_foreign_keys=>true);
ROLLBACK;
-- ensure that coordinator is added to pg_dist_node
SELECT 1 FROM master_add_node('localhost', :master_port, groupId => 0);