Introduction

Firebird uses a page cache to hold pages in memory. It is much quicker to retrieve pages from RAM than to go out onto the disc system and read them physically each time they are required. The following description of how Firebird uses its cache is taken from a posting by Ann Harrison on the Firebird Support mailing list.

The posting was in response to a query asking if there is a way to reduce the memory cache without giving up too much performance? This was itself in respect of a system that was taking a long time to wake up from hibernation and the cause was thought to be the time required to load back all the cache pages from disc before the first query (after hibernation) could be processed. The cause was confirmed and the DBA responsible for the database asked, on the list, how he could reduce the buffer cache as much as possible but still have a responsive system.

Ann has given her permission for this posting to be documented formally as part of the Firebird documentation project.