mirror of https://github.com/citusdata/citus.git
215 lines
8.2 KiB
Plaintext
215 lines
8.2 KiB
Plaintext
CREATE SCHEMA background_rebalance;
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SET search_path TO background_rebalance;
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SET citus.next_shard_id TO 85674000;
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SET citus.shard_replication_factor TO 1;
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ALTER SYSTEM SET citus.background_task_queue_interval TO '1s';
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SELECT pg_reload_conf();
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pg_reload_conf
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---------------------------------------------------------------------
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t
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(1 row)
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CREATE TABLE t1 (a int PRIMARY KEY);
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SELECT create_distributed_table('t1', 'a', shard_count => 4, colocate_with => 'none');
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create_distributed_table
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---------------------------------------------------------------------
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(1 row)
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-- verify the rebalance works - no-op - when the shards are balanced. Noop is shown by wait complaining there is nothing
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-- to wait on.
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SELECT 1 FROM citus_rebalance_start();
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NOTICE: No moves available for rebalancing
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?column?
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---------------------------------------------------------------------
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1
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(1 row)
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SELECT citus_rebalance_wait();
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WARNING: no ongoing rebalance that can be waited on
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citus_rebalance_wait
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---------------------------------------------------------------------
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(1 row)
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SELECT citus_move_shard_placement(85674000, 'localhost', :worker_1_port, 'localhost', :worker_2_port, shard_transfer_mode => 'block_writes');
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citus_move_shard_placement
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---------------------------------------------------------------------
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(1 row)
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-- rebalance a table in the background
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SELECT 1 FROM citus_rebalance_start();
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NOTICE: Scheduled 1 moves as job xxx
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DETAIL: Rebalance scheduled as background job
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HINT: To monitor progress, run: SELECT * FROM pg_dist_background_task WHERE job_id = xxx ORDER BY task_id ASC; or SELECT * FROM get_rebalance_progress();
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?column?
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---------------------------------------------------------------------
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1
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(1 row)
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SELECT citus_rebalance_wait();
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citus_rebalance_wait
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---------------------------------------------------------------------
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(1 row)
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SELECT citus_move_shard_placement(85674000, 'localhost', :worker_1_port, 'localhost', :worker_2_port, shard_transfer_mode => 'block_writes');
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citus_move_shard_placement
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---------------------------------------------------------------------
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(1 row)
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CREATE TABLE t2 (a int);
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SELECT create_distributed_table('t2', 'a' , colocate_with => 't1');
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create_distributed_table
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---------------------------------------------------------------------
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(1 row)
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-- show that we get an error when a table in the colocation group can't be moved non-blocking
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SELECT 1 FROM citus_rebalance_start();
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ERROR: cannot use logical replication to transfer shards of the relation t2 since it doesn't have a REPLICA IDENTITY or PRIMARY KEY
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DETAIL: UPDATE and DELETE commands on the shard will error out during logical replication unless there is a REPLICA IDENTITY or PRIMARY KEY.
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HINT: If you wish to continue without a replica identity set the shard_transfer_mode to 'force_logical' or 'block_writes'.
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SELECT 1 FROM citus_rebalance_start(shard_transfer_mode => 'block_writes');
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NOTICE: Scheduled 1 moves as job xxx
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DETAIL: Rebalance scheduled as background job
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HINT: To monitor progress, run: SELECT * FROM pg_dist_background_task WHERE job_id = xxx ORDER BY task_id ASC; or SELECT * FROM get_rebalance_progress();
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?column?
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---------------------------------------------------------------------
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1
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(1 row)
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SELECT citus_rebalance_wait();
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citus_rebalance_wait
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---------------------------------------------------------------------
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(1 row)
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DROP TABLE t2;
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SELECT citus_move_shard_placement(85674000, 'localhost', :worker_1_port, 'localhost', :worker_2_port, shard_transfer_mode => 'block_writes');
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citus_move_shard_placement
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---------------------------------------------------------------------
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(1 row)
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-- show we can stop a rebalance, the stop causes the move to not have happened, eg, our move back below fails.
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SELECT 1 FROM citus_rebalance_start();
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NOTICE: Scheduled 1 moves as job xxx
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DETAIL: Rebalance scheduled as background job
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HINT: To monitor progress, run: SELECT * FROM pg_dist_background_task WHERE job_id = xxx ORDER BY task_id ASC; or SELECT * FROM get_rebalance_progress();
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?column?
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---------------------------------------------------------------------
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1
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(1 row)
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SELECT citus_rebalance_stop();
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citus_rebalance_stop
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---------------------------------------------------------------------
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(1 row)
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-- waiting on this rebalance is racy, as it sometimes sees no rebalance is ongoing while other times it actually sees it ongoing
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-- we simply sleep a bit here
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SELECT pg_sleep(1);
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pg_sleep
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---------------------------------------------------------------------
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(1 row)
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-- failing move due to a stopped rebalance, first clean orphans to make the error stable
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SET client_min_messages TO WARNING;
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CALL citus_cleanup_orphaned_shards();
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RESET client_min_messages;
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SELECT citus_move_shard_placement(85674000, 'localhost', :worker_1_port, 'localhost', :worker_2_port, shard_transfer_mode => 'block_writes');
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WARNING: shard is already present on node localhost:xxxxx
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DETAIL: Move may have already completed.
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citus_move_shard_placement
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---------------------------------------------------------------------
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(1 row)
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-- show we can't start the rebalancer twice
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SELECT 1 FROM citus_rebalance_start();
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NOTICE: Scheduled 1 moves as job xxx
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DETAIL: Rebalance scheduled as background job
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HINT: To monitor progress, run: SELECT * FROM pg_dist_background_task WHERE job_id = xxx ORDER BY task_id ASC; or SELECT * FROM get_rebalance_progress();
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?column?
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---------------------------------------------------------------------
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1
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(1 row)
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SELECT 1 FROM citus_rebalance_start();
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ERROR: A rebalance is already running as job xxx
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DETAIL: A rebalance was already scheduled as background job
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HINT: To monitor progress, run: SELECT * FROM pg_dist_background_task WHERE job_id = xxx ORDER BY task_id ASC; or SELECT * FROM get_rebalance_progress();
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SELECT citus_rebalance_wait();
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citus_rebalance_wait
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---------------------------------------------------------------------
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(1 row)
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-- show that the old rebalancer cannot be started with a background rebalance in progress
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SELECT citus_move_shard_placement(85674000, 'localhost', :worker_1_port, 'localhost', :worker_2_port, shard_transfer_mode => 'block_writes');
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citus_move_shard_placement
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---------------------------------------------------------------------
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(1 row)
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SELECT 1 FROM citus_rebalance_start();
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NOTICE: Scheduled 1 moves as job xxx
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DETAIL: Rebalance scheduled as background job
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HINT: To monitor progress, run: SELECT * FROM pg_dist_background_task WHERE job_id = xxx ORDER BY task_id ASC; or SELECT * FROM get_rebalance_progress();
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?column?
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---------------------------------------------------------------------
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1
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(1 row)
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SELECT rebalance_table_shards();
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ERROR: A rebalance is already running as job xxx
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DETAIL: A rebalance was already scheduled as background job
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HINT: To monitor progress, run: SELECT * FROM pg_dist_background_task WHERE job_id = xxx ORDER BY task_id ASC; or SELECT * FROM get_rebalance_progress();
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SELECT citus_rebalance_wait();
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citus_rebalance_wait
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---------------------------------------------------------------------
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(1 row)
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DROP TABLE t1;
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-- make sure a non-super user can stop rebalancing
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CREATE USER non_super_user_rebalance WITH LOGIN;
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GRANT ALL ON SCHEMA background_rebalance TO non_super_user_rebalance;
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SET ROLE non_super_user_rebalance;
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CREATE TABLE non_super_user_t1 (a int PRIMARY KEY);
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SELECT create_distributed_table('non_super_user_t1', 'a', shard_count => 4, colocate_with => 'none');
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create_distributed_table
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---------------------------------------------------------------------
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(1 row)
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SELECT citus_move_shard_placement(85674008, 'localhost', :worker_1_port, 'localhost', :worker_2_port, shard_transfer_mode => 'block_writes');
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citus_move_shard_placement
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---------------------------------------------------------------------
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(1 row)
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SELECT 1 FROM citus_rebalance_start();
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NOTICE: Scheduled 1 moves as job xxx
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DETAIL: Rebalance scheduled as background job
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HINT: To monitor progress, run: SELECT * FROM pg_dist_background_task WHERE job_id = xxx ORDER BY task_id ASC; or SELECT * FROM get_rebalance_progress();
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?column?
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---------------------------------------------------------------------
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1
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(1 row)
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SELECT citus_rebalance_stop();
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citus_rebalance_stop
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---------------------------------------------------------------------
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(1 row)
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RESET ROLE;
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SET client_min_messages TO WARNING;
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DROP SCHEMA background_rebalance CASCADE;
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