DB2 Version 9.7 for Linux, UNIX, and Windows

Reorganizing tables offline

Reorganizing tables offline is the fastest way to defragment your tables. Reorganization reduces the amount of space that is required for a table and improves data access and query performance.

About this task

After you have identified the tables that require reorganization, you can run the reorg utility against those tables and, optionally, against any indexes that are defined on those tables.

Before you begin

You must have SYSADM, SYSCTRL, SYSMAINT, DBADM, or SQLADM authority, or CONTROL privilege on the table that is to be reorganized. You must also have a database connection to reorganize a table.

Procedure

  1. To reorganize a table using the REORG TABLE command, simply specify the name of the table. For example:
       reorg table employee
    You can reorganize a table using a specific temporary table space. For example:
       reorg table employee use mytemp
    You can reorganize a table and have the rows reordered according to a specific index. For example:
       reorg table employee index myindex
  2. To reorganize a table using an SQL CALL statement, specify the REORG TABLE command with the ADMIN_CMD procedure. For example:
       call sysproc.admin_cmd ('reorg table employee')
  3. To reorganize a table using the administrative application programming interface, call the db2Reorg API.

What to do next

After reorganizing a table, collect statistics on that table so that the optimizer has the most accurate data for evaluating query access plans.