mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-13 11:04:10 +00:00
8 lines
539 B
SQL
8 lines
539 B
SQL
SELECT sum(cityHash64(*)) FROM test.hits SETTINGS max_threads=40;
|
|
|
|
-- We had a bug which lead to additional compressed data read. test.hits compressed size is about 1.2Gb, but we read more then 3Gb.
|
|
-- Small additional reads still possible, so we compare with about 1.5Gb.
|
|
SYSTEM FLUSH LOGS;
|
|
|
|
SELECT ProfileEvents['ReadBufferFromFileDescriptorReadBytes'] < 1500000000 from system.query_log where query = 'SELECT sum(cityHash64(*)) FROM test.hits SETTINGS max_threads=40;' and current_database = currentDatabase() and type = 'QueryFinish';
|