Method and apparatus for efficient runtime memory access in a database

A method for managing memory used for query execution, the method comprising the computer-implemented steps of:

• allocating a buffer map table with locations that correspond to a buffer pool in a cache memory;
• wherein the cache memory is managed by a cache memory manager;
• wherein the buffer map table is managed by a buffer pool manager that is distinct from said cache memory manager;
• wherein the buffer pool includes a plurality of buffers;
• in response to a need to cache a query working set of a query in the cache memory, the buffer pool manager allocating to the query working set a buffer from the buffer map table that corresponds to a buffer in the buffer pool,
• prior to generating said buffer map table,
• calculating working set memory requirements of an average query;
• generating an estimate of how many queries will be executing at a given time;
• determining how many buffers within the buffer pool are required to accommodate the average query based on the estimate of how many queries will be executing at a given time;
• generating the buffer map table based on the working set requirements of the average query and the estimate of how many queries will be executing at a given time.