Maintaining and improving the performance of the database

You can use the database maintenance tool to calculate statistics for the IBM Spectrum Control database. The tool can also reorganize the database to restore efficiency and improve performance.

About this task

By default, the database maintenance tool runs the Db2® runstats command on all database tables that are used by IBM Spectrum Control. By using the runstats command, the database maintenance tool updates statistics about the characteristics of a table and its associated indexes. Because Db2 uses the statistics to determine access paths to data, when you run the database maintenance tool you help to ensure the effectiveness of the paths that are selected.

By specifying an option of the database maintenance tool, you can instruct the tool to reorganize the database tables, if necessary. A set of formulas are applied to the statistics that were collected about the database to determine if reorganization is necessary. Tables are reorganized by reconstructing rows to eliminate fragmented data and by compacting information. Index data is reorganized into unfragmented, physically contiguous pages.

You can customize the reorganization function in the database maintenance tool by updating a properties file. Properties determine which formulas can trigger database reorganization. You can specify properties that exclude tables from being reorganized based on size. Also, you can specify a property to force database reorganization.