Cache Statistics

The Cache Statistics screen displays caching statistics based on the cache option configured via the XDB Server Configuration utility. The screen displays information in units of 4K memory pages. You can use this information to analyze cache hit ratios and monitor cache effectiveness. The statistics include caching information for all table, dictionary, and index files.

Information Description
Total Pages Shows the number of pages in the cache.
Page Size Size of each page in bytes.
Pages in Use Percentage of the cache pages allocated to all files that use this cache.
Dirty Percentage of total pages in the cache that have not yet been written to disk.
Cache Reads Total number of pages requested from the cache.
Pages Read Total number of pages read into the cache from disk.
Disk Reads Total number of read I/O calls performed. Matches pages read, since pages are requested only one at a time.
Read Hit Percentage of pages requested that did not require a disk read I/O operation.
Cache Writes Total number of dirty pages released to the cache.
Pages Written Total number of pages written to disk.
Disk Writes Total number of disk write I/O calls performed. This number may be less than pages written since flushing causes a series of pages to be written to an accumulator first, and then all written together in one I/O.
Write Hit Percentage of pages released dirty to the cache that were not written to the disk.
Tosses Number of cache pages allocated to a file that were written out to disk to make room for a new page.
Checkpoints Number of checkpoint calls made to this cache.