Minimize CPU Utilization for Buffer Pool Status Update when Calculating Minimum Log Sequence Number Values on a Buffer
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-29
Disclosed is a process for avoiding the buffer status update operation in the performance critical routine that unfixes a buffer. When a buffer is fixed with an X-latch (suggesting possible modification of the buffer), then the buffer status is checked to see if the page has already been modified. If it has not already been modified, then its minimum LSN status is set to the next available LSN. When the page is unfixed, but has not yet been changed, then instead of updating this status to zero the not valid LSN, the status information is not changed. This status information is not cleaned up until a request to find the minimum LSN of all the buffers is received.