Cache page retention based on page cost

A computer program product for retaining data pages in a cache, the computer program product comprising a non-transitory computer-readable storage medium having computer-usable program code embodied therein, the computer-usable program code configured to perform the following when executed by at least one processor:

• store a plurality of data pages in a cache;
• calculate, for each data page of the plurality of data pages, a cost associated with promoting the data page from persistent storage media to the cache, the cost taking into account any data transformation that is needed to promote the data page from the persistent storage media to the cache;
• retain each data page in the cache for an amount time that is associated with its cost;
• and
• as the cache fills, reduce the effect that the cost has on data page retention in the cache.

An apparatus for retaining data pages in a cache, the apparatus comprising:

• at least one processor;
• at least one memory device coupled to the at least one processor and storing instructions for execution on the at least one processor, the instructions causing the at least one processor to:
• store a plurality of data pages in a cache;
• calculate, for each data page of the plurality of data pages, a cost associated with promoting the data page from persistent storage media to the cache, the cost taking into account any data transformation that is needed to promote the data page from the persistent storage media to the cache;
• retain each data page in the cache for an amount time that is associated with its cost;
• and
• as the cache fills, reduce the effect that the cost has on data page retention in the cache.