AUTO_TUNE configuration parameter

Use the AUTO_TUNE configuration parameter to enable or disable all automatic tuning configuration parameters that have values that are not present in the onconfig file.

onconfig.std value
AUTO_TUNE 1
values
0 = disabled
1 = enabled
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.

Usage

If an individual automatic tuning configuration parameter is not set in your current onconfig file, the database server uses the value specified in the AUTO_TUNE configuration parameter for that configuration parameter.

The automatic tuning configuration parameters are:
  • AUTO_AIOVPS
  • AUTO_CKPTS
  • AUTO_LRU_TUNING
  • AUTO_READAHEAD
  • AUTO_REPREPARE
  • AUTO_STAT_MODE

If an automatic tuning configuration parameter is set in the current onconfig file, the database server uses the value that is in the onconfig file. The AUTO_TUNE configuration parameter does not change that value.

Your onconfig file is in the %INFORMIXDIR%\etc or $INFORMIXDIR/etc directory.

Examples

Example 1: Suppose some of your automatic tuning configuration parameters are not set, but others have values:

  • AUTO_LRU_TUNING  (value not set) 
  • AUTO_STAT_MODE  (value not set) 
  • AUTO_LRU_CKPTS  (value not set) 
  • AUTO_AIOVPS 0
  • AUTO_REPREPARE 1
  • AUTO_READAHEAD 0

If you set the AUTO_TUNE configuration parameter to 1, the database server automatically changes the values that are not set to 1. The values that were previously set remain the same. The automatic tuning configuration parameters now have the following values:

  • AUTO_LRU_TUNING  1 
  • AUTO_STAT_MODE  1 
  • AUTO_CKPTS  1 
  • AUTO_AIOVPS 0
  • AUTO_REPREPARE 1
  • AUTO_READAHEAD 0

Example 2: Suppose all of your automatic tuning configuration parameters are set and have the following values:

  • AUTO_LRU_TUNING 1
  • AUTO_STAT_MODE 1
  • AUTO_LRU_CKPTS 1
  • AUTO_AIOVPS 0
  • AUTO_REPREPARE 1
  • AUTO_READAHEAD 0

In this situation, the AUTO_TUNE configuration does not change any of the values.

Example 3: Suppose that you removed the automatic tuning configuration parameters from your onconfig file but now want to use them. You can set AUTO_TUNE to 1 to re-enable all of the automatic tuning configuration parameters.


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