- Buffer pools, Hiper pools, Dataspaces
– Watch pagins for read/write in Statistics reports
– Calculate the Rate/Sec single digit is OK, but you are still paging…. - EDM pool
- RID pool
- Sort/work space – per user
Memory is one DB2s more critical resources, and it probably uses more than other systems running on your processor. The amount of memory used may increase dynamically and significantly with sudden large uses of RID pool facilities, or Sorting requirements.
Overall, keeping data in memory to avoid I/Os is the way to optimize the performance of your applications.
When memory is over-allocated, meaning the amount requested by DB2 is much larger than the amount of real storage on your processor – z/OS will start to move pages to/from expanded memory at ever increasing rates. This will eventually degrade the performance of the entire processor as well as the DB2 system.