mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-15 19:02:04 +00:00
58 lines
1.5 KiB
SQL
58 lines
1.5 KiB
SQL
DROP TABLE IF EXISTS t1;
|
|
|
|
SET allow_experimental_statistic = 1;
|
|
SET allow_statistic_optimize = 1;
|
|
|
|
CREATE TABLE t1
|
|
(
|
|
a Float64 STATISTIC(tdigest),
|
|
b Int64 STATISTIC(tdigest),
|
|
pk String,
|
|
) Engine = MergeTree() ORDER BY pk
|
|
SETTINGS min_bytes_for_wide_part = 0;
|
|
|
|
SHOW CREATE TABLE t1;
|
|
|
|
INSERT INTO t1 select number, -number, generateUUIDv4() FROM system.numbers LIMIT 10000;
|
|
|
|
SELECT 'After insert';
|
|
EXPLAIN SYNTAX SELECT count(*) FROM t1 WHERE b < 10 and a < 10;
|
|
SELECT count(*) FROM t1 WHERE b < 10 and a < 10;
|
|
SELECT count(*) FROM t1 WHERE b < NULL and a < '10';
|
|
|
|
ALTER TABLE t1 DROP STATISTIC a, b TYPE tdigest;
|
|
|
|
SELECT 'After drop statistic';
|
|
EXPLAIN SYNTAX SELECT count(*) FROM t1 WHERE b < 10 and a < 10;
|
|
SELECT count(*) FROM t1 WHERE b < 10 and a < 10;
|
|
|
|
SHOW CREATE TABLE t1;
|
|
|
|
ALTER TABLE t1 ADD STATISTIC a, b TYPE tdigest;
|
|
|
|
SELECT 'After add statistic';
|
|
|
|
SHOW CREATE TABLE t1;
|
|
|
|
ALTER TABLE t1 MATERIALIZE STATISTIC a, b TYPE tdigest;
|
|
INSERT INTO t1 select number, -number, generateUUIDv4() FROM system.numbers LIMIT 10000;
|
|
|
|
SELECT 'After materialize statistic';
|
|
EXPLAIN SYNTAX SELECT count(*) FROM t1 WHERE b < 10 and a < 10;
|
|
SELECT count(*) FROM t1 WHERE b < 10 and a < 10;
|
|
|
|
OPTIMIZE TABLE t1 FINAL;
|
|
|
|
SELECT 'After merge';
|
|
EXPLAIN SYNTAX SELECT count(*) FROM t1 WHERE b < 10 and a < 10;
|
|
SELECT count(*) FROM t1 WHERE b < 10 and a < 10;
|
|
|
|
ALTER TABLE t1 RENAME COLUMN b TO c;
|
|
SHOW CREATE TABLE t1;
|
|
|
|
SELECT 'After rename';
|
|
EXPLAIN SYNTAX SELECT count(*) FROM t1 WHERE c < 10 and a < 10;
|
|
SELECT count(*) FROM t1 WHERE c < 10 and a < 10;
|
|
|
|
DROP TABLE IF EXISTS t1;
|