DefragThreshold

The DefragThreshold attribute defines the level of online defragmentation. Higher values trigger more intense defragmentation, targeting row pages even when they contain a relatively small number of rows. It leads to more space being freed.

The acceptable values range from 1 to 3 with each value corresponding to a specific level of defragmentation sensitivity. For details, see Online Defragmentation of TimesTen Databases in the Oracle TimesTen In-Memory Database Operations Guide.

The defragmentation process obtains table locks and row locks while executing defragmentation. Higher DefragThreshold values cause more pages to be defragmented, as more row pages become eligible for defragmentation. As a result, table and row locks are acquired more often, which increases the likelihood of lock contention or conflicts with concurrent transactions.

Required Privilege

Only the instance administrator can change the value of this attribute.

Setting

Set DefragThreshold as follows:

Where to set the attribute How the attribute is represented Setting

C or Java programs or UNIX and Linux systems odbc.ini file in TimesTen

DefragThreshold

  • 1 - low
  • 2 - medium (default)
  • 3 - high

Note:

You can view or modify the setting using ttDBConfig built-in. See ttDBConfig.