Optimize Memory Use

Understanding how Sybase IQ allocates memory can help you get the best performance from your system.

• Paging Increases Available Memory
  Although paging increases the amount of available memory, avoid or minimize page swapping for good memory management.
• Utilities to Monitor Swapping
  Use the utilities on your operating system to find out if your system is paging excessively.
• Server Memory
  Sybase IQ allocates heap memory for buffers, transactions, databases, and servers. Shared memory may also be used, but in much smaller quantities.
• Manage Buffer Caches
  Default cache sizes (16MB for the main and 12MB for the temporary cache) are too low for most databases. Allocate as much memory as possible to the IQ main and temporary buffer caches.
• Determine the Sizes of the Buffer Caches
  Calculating the correct buffer cache size depends on several factors.
• Set the Buffer Cache Sizes
  Sybase IQ initially sets the size of the main and temporary buffer caches to 16MB and 12MB respectively. Change the default size of the main and temporary buffer caches to accommodate your applications.
• Specify the Page Size
  Page size and buffer cache size affect memory use and disk I/O throughput for the database.
• Optimize for Large Numbers of Users
  To support the maximum number of users, you may need to increase the temporary dbspace, adjust the operating system parameters, and change the startup parameters.
• Platform-Specific Memory Options
  The total amount of usable memory is limited only by the virtual memory of the system.