mirror of
https://github.com/timescale/timescaledb.git
synced 2025-05-23 14:39:15 +08:00
4e1e15f079
New cluster-like command which writes to a new index than swaps, much like is done for the data table, and only acquires exclusive locks for said swap. This trades off disk usage for lower contention: we hold locks for a much lower period of time, allowing reads to work concurrently, but we have both the old and new versions of the table existing at once, approximately doubling storage usage while reorder is running. Currently only works on chunks.
89 lines
2.3 KiB
SQL
89 lines
2.3 KiB
SQL
-- Copyright (c) 2016-2018 Timescale, Inc. All Rights Reserved.
|
|
--
|
|
-- This file is licensed under the Apache License,
|
|
-- see LICENSE-APACHE at the top level directory.
|
|
|
|
CREATE TABLE cluster_test(time timestamptz, temp float, location int);
|
|
|
|
SELECT create_hypertable('cluster_test', 'time', chunk_time_interval => interval '1 day');
|
|
|
|
-- Show default indexes
|
|
SELECT * FROM test.show_indexes('cluster_test');
|
|
|
|
-- Create two chunks
|
|
INSERT INTO cluster_test VALUES ('2017-01-20T09:00:01', 23.4, 1),
|
|
('2017-01-21T09:00:01', 21.3, 2);
|
|
|
|
-- Run cluster
|
|
CLUSTER VERBOSE cluster_test USING cluster_test_time_idx;
|
|
|
|
-- Create a third chunk
|
|
INSERT INTO cluster_test VALUES ('2017-01-22T09:00:01', 19.5, 3);
|
|
|
|
-- Show clustered indexes
|
|
SELECT indexrelid::regclass, indisclustered
|
|
FROM pg_index
|
|
WHERE indisclustered = true ORDER BY 1;
|
|
|
|
-- Reorder just our table
|
|
CLUSTER VERBOSE cluster_test;
|
|
|
|
-- Show clustered indexes, including new chunk
|
|
SELECT indexrelid::regclass, indisclustered
|
|
FROM pg_index
|
|
WHERE indisclustered = true ORDER BY 1;
|
|
|
|
-- Reorder all tables (although will only be our test table)
|
|
CLUSTER VERBOSE;
|
|
|
|
-- Change the clustered index
|
|
CREATE INDEX ON cluster_test (time, location);
|
|
|
|
CLUSTER VERBOSE cluster_test using cluster_test_time_location_idx;
|
|
|
|
-- Show updated clustered indexes
|
|
SELECT indexrelid::regclass, indisclustered
|
|
FROM pg_index
|
|
WHERE indisclustered = true ORDER BY 1;
|
|
|
|
--check the setting of cluster indexes on hypertables and chunks
|
|
ALTER TABLE cluster_test CLUSTER ON cluster_test_time_idx;
|
|
|
|
SELECT indexrelid::regclass, indisclustered
|
|
FROM pg_index
|
|
WHERE indisclustered = true
|
|
ORDER BY 1,2;
|
|
|
|
CLUSTER VERBOSE cluster_test;
|
|
|
|
ALTER TABLE cluster_test SET WITHOUT CLUSTER;
|
|
|
|
SELECT indexrelid::regclass, indisclustered
|
|
FROM pg_index
|
|
WHERE indisclustered = true
|
|
ORDER BY 1,2;
|
|
|
|
\set ON_ERROR_STOP 0
|
|
CLUSTER VERBOSE cluster_test;
|
|
\set ON_ERROR_STOP 1
|
|
|
|
ALTER TABLE _timescaledb_internal._hyper_1_1_chunk CLUSTER ON _hyper_1_1_chunk_cluster_test_time_idx;
|
|
|
|
SELECT indexrelid::regclass, indisclustered
|
|
FROM pg_index
|
|
WHERE indisclustered = true
|
|
ORDER BY 1,2;
|
|
|
|
CLUSTER VERBOSE _timescaledb_internal._hyper_1_1_chunk;
|
|
|
|
ALTER TABLE _timescaledb_internal._hyper_1_1_chunk SET WITHOUT CLUSTER;
|
|
|
|
SELECT indexrelid::regclass, indisclustered
|
|
FROM pg_index
|
|
WHERE indisclustered = true
|
|
ORDER BY 1,2;
|
|
|
|
\set ON_ERROR_STOP 0
|
|
CLUSTER VERBOSE _timescaledb_internal._hyper_1_1_chunk;
|
|
\set ON_ERROR_STOP 1
|