Every cache has a “hit ratio”: the percentage of time that a requested piece of information is available in it. You can check the hit ratio of the index cache, the data cache, and the data file cache to determine whether to increase the cache size.
To check cache hit ratios, see “Checking Cache Hit Ratios” in Oracle Essbase Administration Services Online Help.
The cache hit ratio indicates the percentage of time that a requested piece of information is already in the cache. A higher hit ratio indicates that the data is in the cache more often. This improves performance, because the requested data need not be retrieved from disk for the next process. A hit ratio of 1.0 indicates that every time data is requested, it is found in the cache. This is the maximum performance possible from a cache setting.
The Hit Ratio on Index Cache setting indicates the Essbase kernel success rate in locating index information in the index cache without having to retrieve another index page from disk.
The Hit Ratio on Data File Cache setting indicates the Essbase kernel success rate in locating data file pages in the data file cache without having to retrieve the data file from disk.
The Hit Ratio on Data Cache setting indicates the Essbase success rate in locating data blocks in the data cache without having to retrieve the block from the data file cache.
Check memory allocation. Add smaller amounts of memory at a time , if needed, because a smaller increment may have the same benefit as a large one. Large, incremental allocations of memory usually result in very little gain in the hit ratio.