DB2 Performance Advice: Read Time(ms)
This metric shows the average read time duration as computed by ((POOL_READ_TIME ms) / (POOL_DATA_P_READS + POOL_INDEX_P_READS)).
Average Read Time can be improved by:
- Eliminating scans from the statement workload. The less prefetch asynchronous I/O that DB2 performs, then less demand will be placed upon disk drives and controllers and performance will improve.
- Ensuring that tablespace containers have equal sizes (DMS) and are distributed across available disk drives. The last thing you want is multiple containers on the same disk, or containers placed on OS paging devices.
To reduce average read times:
- Analyze the SQL workload to find statements with the highest rows read and CPU costs, then implement indexes, Clustering indexes, MDC tables, or MQTs to improve statement speed and efficiency. For best results
in the least amount of time, DBI suggests using pureFeat.
- Find the tablespace with the slowest average Read Time(ms) and carefully analyze the definition of its containers. Why is this tablespace so much slower than the database overall? Refer to improvement advice #2 above.