Patent ID: 7421562
Filing Date: 2008-09-02
Classification: G06F

Abstract:
1. A method for extended memory support in a database system having a primary cache for storing database pages, the method comprising: using a memory mapped file, creating a secondary cache in system memory available to the database system; mapping a virtual address range to at least a portion of the secondary cache; when the primary cache is full, replacing database pages from the primary cache using the secondary cache; in response to a request for a particular database page, searching for the database particular page in the secondary cache if the particular database page is not found in the primary cache; if the particular database page is found in the secondary cache, determining a virtual address in the secondary cache where the particular database page resides based on the mapping; and swapping the particular database page found in the secondary cache with a database page in the primary cache, so as to replace a database page in the primary cache with the particular database page from the secondary cache.