This metric shows the total number of active sorts currently underway. Sorts are very expensive in terms of CPU, and also I/O time if active sorts are overflowing to TEMPSPACE. If the database is a data warehouse database, the majority of sorts tend to overflow SORTHEAP memory. You may be able to use this metric to gauge how much TEMPSPACE disk storage you are currently using. There are no alerts or warnings for this metric, but, as you become familiar with the norms of your database, it would be a good idea to set your own appropriate warning and alert thresholds.
Tip: Reducing Sort Costs
To reduce the number of sorts and save substantial CPU cycles, use the statistics to identify the statements having the highest aggregate sort time costs. Create clustering indexes to reduce sort costs, or convert the table to an MDC table if appropriate.