Memory Options

SAP Sybase IQ uses memory for a variety of purposes.

• IQ Buffer Cache Size Controls
  The IQ Buffer Cache Size options, as well as other options you can set once the server is running, determine how much memory is available.
• IQ Buffer Partitioning Control
  By default, buffer partitioning based on the number of CPUs is enabled. Adjust the partitions to improve load or query performance.
• Concurrent User Switches
  Your license sets the absolute number of concurrent users. The required -gm switch limits the number of concurrent user connections on a particular server.
• Concurrent Query Switch
  To limit the number of user connections to fewer than your license allows, use the -iqgovern switch to control query use.
• Wired Memory Switch
  The -iqwmem switch creates a pool of “wired” memory on certain UNIX platforms only.
• Number of Processing Threads
  SAP Sybase IQ assigns varying numbers of kernel threads to each user connection, based on the type of processing being done by that process, the total number of threads available, and the setting of various options. Increasing the number of threads might improve performance.
• Number of Processors
  On a multiprocessor machine, use the -gt option, to set the number of processors used by the database server for catalog store operations.
• Catalog Store Cache Size
  Use the -c switch to set the amount of memory in the cache for the catalog store.
• Number of CPUs Switch
  The -iqnumbercpus switch on the SAP Sybase IQ startup command specifies the number of CPUs available to IQ, overriding the physical number of CPUs for resource planning purposes.