Sizing the Data File Cache

The data file cache holds data files (.pag files) in memory if you are using direct I/O. If you are not using direct I/O, the data file cache is not used. How much of the data within data files can fit into memory simultaneously depends on the amount of memory you allocate to the data file cache.

In general, if you must choose whether to allocate memory to the data cache or to the data file cache, choose the data file cache if you are using direct I/O.

Table 173 shows default and recommended settings for the data file cache:

Table 173. Data File Cache Size Settings

Minimum Value

Default Value

Recommended Value

Direct I/O: 10,240 KB (10,485,760 bytes)

Direct I/O: 32,768 KB (33,554,432 bytes)

Combined size of all essn.pag files, if possible; otherwise, as large as possible.

This cache setting not used if Essbase is set to use buffered I/O.

In general, if you are using direct I/O, make the data file cache as large as system resources allow. If you are using buffered I/O, the data file cache is not used.

For information on testing and fine-tuning cache settings, see Fine-Tuning Cache Settings.