Optimizing Asynchronous I/O Reads
Purpose
Asynchronous I/O allows a program to execute other tasks immediately after initiating an I/O operation. This prevents threads from idling while waiting for I/O completion, thereby improving CPU utilization and overall throughput.
Procedure
- Log in to ClickHouse client.
1clickhouse -m -n
- Set asynchronous I/O read.
1 2
set preferred_block_size_bytes=2000000; set allow_asynchronous_read_from_io_pool_for_merge_tree=true;

- Exit the ClickHouse client.
1quit;
Parent topic: ClickHouse Tuning