AUTO_LRU_TUNING configuration parameter

Use the AUTO_LRU_TUNING configuration parameter to enable automatic LRU tuning, which automatically maintains enough clean pages for page replacement.

onconfig.std value
Not set. If the AUTO_TUNE configuration parameter is set to 1, automatic LRU tuning is enabled.
values
0 = Off

1 = On

takes effect
After you edit your onconfig file and restart the database server.
When you reset the value dynamically in your onconfig file by running the onmode -wf command.
When you reset the value in memory by running the onmode -wm command.
If an AUTO_LRU_TUNING value is not set in your current onconfig file and you edit the AUTO_TUNE configuration parameter and restart the database server

Usage

Automatic LRU tuning changes affect all buffer pools, and adjust the lru_min_dirty and lru_max_dirty values in the BUFFERPOOL configuration parameter.

Starting with Informix server version 15.0.1.x, user can change the BUFFERPOOL configuration parameter on the fly. Some of the attributes i.e. buffers and lrus are not dynamically tunable. lru_min_dirty and lru_max_dirty can be tuned dynamically. However, If AUTO_LRU_TUNING is set to 1, any onmode -w[mf] command that attempts to modify lru_min_dirty or lru_max_dirty for a buffer pool, fails with the message In order to manually modify lru min or max for a buffer pool, AUTO_LRU_TUNING must be disabled.