DB2 10.5 for Linux, UNIX, and Windows

Self-tuning memory overview

Self-tuning memory simplifies the task of memory configuration by automatically setting values for memory configuration parameters and sizing buffer pools. When enabled, the memory tuner dynamically distributes available memory resources among the following memory consumers: buffer pools, locking memory, package cache, and sort memory.

Self-tuning memory is enabled through the self_tuning_mem database configuration parameter.

The following memory-related database configuration parameters can be automatically tuned:

database_memory - Database shared memory size
locklist - Maximum storage for lock list
maxlocks - Maximum percent of lock list before escalation
pckcachesz - Package cache size
sheapthres_shr - Sort heap threshold for shared sorts
sortheap - Sort heap size

Starting withDB2® Cancun Release 10.5.0.4, each member in a DB2 pureScale® environment has its own self-tuning memory manager (STMM) tuner.

Starting withDB2 Version 10.5 Fix Pack 5, the following memory-related database configuration parameters can also be automatically tuned in a DB2 pureScale environment:

cf_db_mem_sz - CF Database memory
cf_gbp_sz - Group buffer pool
cf_lock_sz- CF Lock manager
cf_sca_sz - Shared communication area