• SAPDBA is installed correctly. Refer to SAPDBA Setup.

• You are logged on in expert mode, that is, as user informix , and you have started SAPDBA. Refer to Starting SAPDBA.
• You have completed a storage analysis of tables and indexes with SAPDBA. This helps you identify the tables or the dbspace that needs reorganization.

1. You choose a reorganization method, depending on the purpose of the reorganization:

· Tables in Dbspace by ‘alter fragment...’ and Tables Listed in File by ‘alter fragment...’

The "alter fragment" method is the fastest. However, SAPDBA does not alter the storage parameters (although some tables that were scattered might end up with fewer extents) and the table statistics are not updated. This is best if you want to move tables to another dbspace.

Refer to Reorganizing a Group of Tables with SAPDBA.

· Tables in Dbspace by 'insert into select from …' and Tables Listed in File by 'insert into select from …'

The "insert into select from" method tunes the storage parameters for each table optimally, so this is best if you want to reclaim space.

Refer to Reorganizing a Group of Tables with SAPDBA.

· Reorganize Dbspace

This uses the "alter fragment" or the "insert into select from" method, depending on the phase of the reorganization and the Informix version that you are using. This method is normally a good compromise. For more information, see Reorganizing a Dbspace and Its Tables with SAPDBA.

If you use the "tables in dbspace" methods, then SAPDBA reorganizes all the tables of the dbspace. If you use the "tables listed in file" methods, then SAPDBA uses a file containing a list of dbspaces and other parameters. You must set up the file yourself before the reorganization.

2. You prepare for the reorganization.
3. You perform the reorganization.
4. You finish the reorganization.

After a reorganization, your database is less likely to run into space problems. However, you need to keep on monitoring the space situation. Refer to Storage Analysis of Tables and Indexes with SAPDBA.