Chapter 11. Performance tuning of DB2 UDB Workgroup Server 385
without an order by clause. The DBA should monitor if the sort heap is big
enough. If not, the DBA must increase the heap size when better performance is
necessary and more memory is available.
Be careful when increasing the sort heap. Because the heap is part of the agent
memory, for each connection, the space is allocated and that multiplies the
memory required by the number of agents.
To determine whether you have a sort performance problem, look at the total
CPU time spent on sorting compared to the time spent for the whole application
using, for example, the snapshot monitor for database and database manager. If
total sort time is a large portion of CPU time for the application, ...