use numbers_mt instead numbers

[den-crane]

mt - multi thread

select * from system.numbers limit 1000000000 format Null;
0 rows in set. Elapsed: 0.475 sec. Processed 1.00 billion rows, 8.00 GB (2.10 billion rows/s., 16.83 GB/s.)

select * from system.numbers_mt limit 1000000000 format Null;
0 rows in set. Elapsed: 0.305 sec. Processed 1.00 billion rows, 8.00 GB (3.28 billion rows/s., 26.21 GB/s.)

[ernado]

Thank you!

[ernado]

I've also used following command to get results for clickhouse-client:

$ clickhouse-client --query "SELECT number FROM system.numbers_mt LIMIT 500000000" --format Null --time
0.529

Seems like using FORMAT Null in query results in no data sent to client.