## OMS History Cache Hit Rate

OMS history cache hit rate <percentage>%, <number> of <number of> accesses failed

### Explanation

This message can occur for liveCache instances only.

The hit rate when accessing history data (links to undo log entries for the object) in the data cache is too low. In a running liveCache application, the hit rate should not fall below 100%, otherwise the data must be read physically.

The hit rate may fall for short periods of time, for example, when objects are accessed for the first time.

### User Response

Check the following points:

- The data cache load
- The size of the plan version
- Long-running OMS versions
- Configuration of the liveCache instance and the hardware

See also:

Concepts of the Database System, History Management