To assess the need for running reorg, use statistics from the systabstats table and the optdiag utility. systabstats contains statistics on the utilization of table space, while optdiag generates reports based on statistics in both systabstats and the sysstatistics table.
For information on the systabstats table, see Chapter 2, “Statistics Tables and Displaying Statistics with optdiag” in the Performance and Tuning Series: Physical Database Tuning. For information about optdiag, see Utility Programs for UNIX Platforms.