Determine the Sizes of the Buffer Caches

Calculating the correct buffer cache size depends on several factors.

• Operating System and Other Applications
  Most operating systems use a large percent of available memory for file system buffering. Understand the buffering policies for your operating system to avoid over-allocating memory.
• Memory Overhead
  After you determine how much physical memory the operating system and other applications require, calculate how much of the remaining memory is required by Sybase IQ.
• Main and Temp Buffer Caches
  A general guideline for cache sizes is 40% for the main buffer cache and 60% for the temp buffer cache. Start with this guideline, monitor server performance, then adjust the cache size as necessary.