Databases: object caching

Self-tutoring about computer systems: the tutor looks into what an object cache does.

As I understand it, object caching is the storage of the answers to questions received by a database. The questions are called queries.

A given query of a database will likely involve a large number of operations (value comparisons, etc). Moreover, the reply could include a list of dozens, or many more, records. Performing the comparisons, then editing the list of positives, creates demand on the server.

Put simply, an object cache is a folder of such replies. Typically it will accumulate the common queries quickly. Then, when the database receives a query, it checks the object cache folder to see if that query has been answered before. If so, the object cache folder will also contain the reply, a copy of which the server can just send along without thinking more about it. Therefore, using an object cache can significantly reduce server demand.

As the database contents change, the replies in the object cache can become outdated; therefore, the object cache should be refreshed every so often.

Source:

wpastra.com