Configuration parameters that affect memory utilization

A large number of configuration parameters in the ONCONFIG file affect memory utilization and performance.

The following configuration parameters significantly affect memory utilization:
  • BUFFERPOOL
  • DS_NONPDQ_QUERY_MEM
  • DS_TOTAL_MEMORY
  • EXTSHMADD
  • LOCKS
  • LOGBUFF
  • LOW_MEMORY_MGR
  • LOW_MEMORY_RESERVE
  • PHYSBUFF
  • RESIDENT
  • SHMADD
  • SHMBASE
  • SHMTOTAL
  • SHMVIRTSIZE
  • SHMVIRT_ALLOCSEG
  • STACKSIZE
  • Memory cache parameters (see Configure and monitor memory caches)
  • Network buffer size (see Network buffer pools)

The SHMBASE parameter indicates the starting address for database server shared memory. When set according to the instructions in the machine notes file or release notes file, this parameter has no appreciable effect on performance. For the path name of each file, see the Introduction to this guide.

The DS_NONPDQ_QUERY_MEM parameter increases the amount of memory that is available for non-PDQ queries. You can only use this parameter if PDQ priority is set to zero. For more information, see Configuring memory for queries with hash joins, aggregates, and other memory-intensive elements.

The following sections describe the performance effects and considerations associated with some of the configuration parameters that are listed at the beginning of this section.


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