Estimating compression

Update the estimate of the amount of space that you can save if you compress data in tables, indexes, and fragments.

Prerequisite: To estimate compression savings for tables and table fragments, the HCL OpenAdmin Tool (OAT) for Informix® requires HCL Informix version 11.50.xC6 or later. To estimate compression for indexes and for tables that contain simple large objects (TEXT and BYTE data types), OAT requires Informix 12.10.

You can use the compression estimate to determine whether you want to compress data in a table, index, or fragment. The compression estimate for tables and table fragments includes simple large objects (TEXT and BYTE data types). If a compression estimate is available, it is displayed on the Space Administration > Storage > Tables and Indexes page, in the Space Usage column. The time of the latest estimate is indicated in the hover help.

To update the compression estimate:

On the OAT menu, click Space Administration > Storage.
With the database server selected, expand the Tables and Indexes panel.
Select the tables, indexes, and fragments.
Click Actions > Update Data.

To monitor the progress of the task, click the Task Status tab.