Caching tables for EIM

One other measure that can help performance is to pin small tables that are frequently accessed in cache. The value of BUFFER_POOL_KEEP determines the 'keep pool', example, the portion of the buffer cache that will not be flushed by the LRU algorithm.

The 'keep pool' allows one to 'pin' certain tables in memory, thus improving performance for accessing those tables. This will ensure that after the first time that the table is accessed it will always be in memory. Otherwise it is possible that the table will get pushed out of memory and will require disk access the next time used. Keep in mind that the amount of memory allocated to the ‘keep’ area is subtracted from the overall buffer cache memory (defined by DB_BLOCK_BUFFERS).

A good candidate for this would be the S_LST_OF_VAL table. The syntax for pinning a table in cache is as follows:

ALTER TABLE S_LST_OF_VAL CACHE;