mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-13 02:53:38 +00:00
81aeff2d2a
With JOIN from system.clusters one can figure out from which server data came. TODO: - optimization to avoid communicating with unrelated shards (for queries like "AND _shard_num = n") - fix aliases (see tests with serverError expected) v0: AddingConstColumnBlockInputStream v2: VirtualColumnUtils::rewriteEntityInAst v3: fix remote(Distributed) by appending _shard_num only if has been requested
73 lines
2.5 KiB
SQL
73 lines
2.5 KiB
SQL
-- make the order static
|
|
SET max_threads = 1;
|
|
|
|
-- remote(system.one)
|
|
SELECT 'remote(system.one)';
|
|
SELECT * FROM remote('127.0.0.1', system.one);
|
|
SELECT * FROM remote('127.0.0.{1,2}', system.one);
|
|
SELECT _shard_num, * FROM remote('127.0.0.1', system.one);
|
|
SELECT _shard_num, * FROM remote('127.0.0.{1,2}', system.one);
|
|
SELECT _shard_num, * FROM remote('127.0.0.{1,2}', system.one) WHERE _shard_num = 1;
|
|
|
|
-- dist_1 using test_shard_localhost
|
|
SELECT 'dist_1';
|
|
CREATE TABLE mem1 (key Int) Engine=Memory();
|
|
CREATE TABLE dist_1 AS mem1 Engine=Distributed(test_shard_localhost, currentDatabase(), mem1);
|
|
SELECT _shard_num FROM dist_1;
|
|
|
|
INSERT INTO mem1 VALUES (10);
|
|
SELECT _shard_num FROM dist_1;
|
|
SELECT _shard_num, key FROM dist_1;
|
|
SELECT key FROM dist_1;
|
|
|
|
INSERT INTO dist_1 VALUES (20);
|
|
SELECT _shard_num FROM dist_1;
|
|
SELECT _shard_num, key FROM dist_1;
|
|
SELECT key FROM dist_1;
|
|
|
|
-- dist_2 using test_cluster_two_shards_localhost
|
|
SELECT 'dist_2';
|
|
CREATE TABLE mem2 (key Int) Engine=Memory();
|
|
CREATE TABLE dist_2 AS mem2 Engine=Distributed(test_cluster_two_shards_localhost, currentDatabase(), mem2);
|
|
SELECT _shard_num FROM dist_2;
|
|
|
|
INSERT INTO mem2 VALUES (100);
|
|
SELECT _shard_num FROM dist_2;
|
|
SELECT _shard_num, key FROM dist_2;
|
|
SELECT key FROM dist_2;
|
|
|
|
-- multiple _shard_num
|
|
SELECT 'remote(Distributed)';
|
|
SELECT _shard_num, key FROM remote('127.0.0.1', currentDatabase(), dist_2);
|
|
|
|
-- JOIN system.clusters
|
|
SELECT 'JOIN system.clusters';
|
|
|
|
SELECT a._shard_num, a.key, b.host_name, b.host_address, b.port
|
|
FROM (SELECT *, _shard_num FROM dist_1) a
|
|
JOIN system.clusters b
|
|
ON a._shard_num = b.shard_num
|
|
WHERE b.cluster = 'test_cluster_two_shards_localhost';
|
|
-- Requires toUInt32() otherwise Type mismatch of columns (53)
|
|
SELECT _shard_num, key, b.host_name, b.host_address, b.port
|
|
FROM dist_1 a
|
|
JOIN system.clusters b
|
|
ON toUInt32(_shard_num) = b.shard_num
|
|
WHERE b.cluster = 'test_cluster_two_shards_localhost';
|
|
|
|
-- rewrite does not work with aliases, hence Missing columns (47)
|
|
SELECT a._shard_num, key FROM dist_1 a; -- { serverError 47; }
|
|
-- the same with JOIN, just in case
|
|
SELECT a._shard_num, a.key, b.host_name, b.host_address, b.port
|
|
FROM dist_1 a
|
|
JOIN system.clusters b
|
|
ON a._shard_num = b.shard_num
|
|
WHERE b.cluster = 'test_cluster_two_shards_localhost'; -- { serverError 47; }
|
|
|
|
SELECT 'dist_3';
|
|
CREATE TABLE mem3 (key Int, _shard_num String) Engine=Memory();
|
|
CREATE TABLE dist_3 AS mem3 Engine=Distributed(test_shard_localhost, currentDatabase(), mem3);
|
|
INSERT INTO mem3 VALUES (100, 'foo');
|
|
SELECT * FROM dist_3;
|
|
SELECT _shard_num, * FROM dist_3;
|