When you enable the automatic PLAN_TABLE creation option, the
started task will automatically create a PLAN_TABLE if none exists
for the qualifier of a particular target SQL statement. Depending
on the usage of the EXPLAIN feature, the result could be that many
tables are created.
Note: This option only applies to DB2 versions 6 and 7.
To avoid creating a large number of tables, you can explicitly
create the plan tables for those qualifiers for which you want EXPLAIN
support enabled, and specify NO, in the automatic PLAN_TABLE creation
option of the DB2EXPLAIN entry for the DB2 subsystem.