mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-23 16:12:01 +00:00
30 lines
1.3 KiB
SQL
30 lines
1.3 KiB
SQL
DROP TABLE IF EXISTS t_optimize_equal_ranges;
|
|
|
|
CREATE TABLE t_optimize_equal_ranges (a UInt64, b String, c UInt64) ENGINE = MergeTree ORDER BY a;
|
|
|
|
SET max_block_size = 1024;
|
|
SET max_bytes_before_external_group_by = 0;
|
|
SET optimize_aggregation_in_order = 0;
|
|
SET optimize_use_projections = 0;
|
|
|
|
INSERT INTO t_optimize_equal_ranges SELECT 0, toString(number), number FROM numbers(30000);
|
|
INSERT INTO t_optimize_equal_ranges SELECT 1, toString(number), number FROM numbers(30000);
|
|
INSERT INTO t_optimize_equal_ranges SELECT 2, toString(number), number FROM numbers(30000);
|
|
|
|
SELECT a, uniqExact(b) FROM t_optimize_equal_ranges GROUP BY a ORDER BY a SETTINGS max_threads = 16;
|
|
SELECT a, uniqExact(b) FROM t_optimize_equal_ranges GROUP BY a ORDER BY a SETTINGS max_threads = 1;
|
|
SELECT a, sum(c) FROM t_optimize_equal_ranges GROUP BY a ORDER BY a SETTINGS max_threads = 16;
|
|
SELECT a, sum(c) FROM t_optimize_equal_ranges GROUP BY a ORDER BY a SETTINGS max_threads = 1;
|
|
|
|
SYSTEM FLUSH LOGS;
|
|
|
|
SELECT
|
|
used_aggregate_functions[1] AS func,
|
|
Settings['max_threads'] AS threads,
|
|
ProfileEvents['AggregationOptimizedEqualRangesOfKeys'] > 0
|
|
FROM system.query_log
|
|
WHERE type = 'QueryFinish' AND current_database = currentDatabase() AND query LIKE '%SELECT%FROM%t_optimize_equal_ranges%'
|
|
ORDER BY func, threads;
|
|
|
|
DROP TABLE t_optimize_equal_ranges;
|