Server Optimization Policies
Use this page to configure the database server to automatically compress, repack, shrink, and defragment tables and fragments, and to remove in-place alter operations from tables.
Prerequisites: For the
space optimization policies, the OpenAdmin Tool (OAT) for Informix® requires IBM®
Informix 11.70
or later. To compress indexes and simple large objects
(TEXT and BYTE data types), OAT requires Informix 12.10.
You can enable or disable the Scheduler task that implements the optimization policies. The policies set the thresholds that determine when to compress, shrink, repack, and defragment the tables and fragments. You can update the thresholds for each of these operations or disable any of them. You can also specify when the Scheduler task runs.
- Policies
- Enable the selected policies
- Select this option to enable the Scheduler task. Then enable the specific policies and set the thresholds.
- Compress
- Build a compression dictionary and compress the tables and table fragments that are not compressed. A separate compression dictionary is built for each individual compressed fragment and each compressed, non-fragmented table.
- Repack
- Consolidate free space in the tables and fragments.
- Shrink
- Return any free space in the tables and table fragments to the dbspace. Returning free space reduces the total size of the tables and fragments.
- Defragment extents
- Merge extents in the tables and table fragments to reduce the number of extents.
- Remove outstanding in-place alter operations
- Select this option to remove in-place alters from tables, and remove data pages that have outdated definitions for tables.
- Specify when to run the task for the enabled policies
- The task runs once a week by default. You can specify a different frequency, a time to start the task, or the days on which to run the task.