Disk Cache Memory Parameters

The JADE database engine can make effective use of memory assigned to file caching to avoid or postpone input‑output operations in order to improve database performance.

However, if the total memory in use on your computer exceeds the physical memory available, the negative performance impact incurred by operating system paging activity may more than offset the benefits of this caching. For this reason, disk cache memory parameters need to be carefully selected to make effective use of available physical memory. One way to select optimal values for memory parameters is by testing the effect of changes in the target environment. Effects can be determined by timing specific units of work and by using the database statistics pdb_statistics.log file.

As certain parameters interact with each other (and indeed with other operating system‑configurable options), it may be necessary to make multiple passes, stabilizing each parameter in turn.