If we use EPLAIN YES option while binding the packages, DB2 writes the details of access paths choosen by all the SQLs(assigning each of them a unique no.) in the plan_table. You can analyze these paths and can change the SQL or add/remove indexes to improve the performance.
Please let me know if you need further clarification.
EXPLAIN is a very typical thing.
it gives you the following information.
1. Whether the DB2 has made use of index, and if yes which all indexes.
2. Whether a join criteria satisfied in the table.
3. Whether the table uses sort.
4. All the information about the access path used.
5. All the information about the user-defined functions used.
6. Based on these it gives the estimation cost of the QUREY, the most important thing to know.#
all this information is published in the PDS PLAN_TABLE.
Assuming the PLAN table has been in place on your id ;
the u can issue EXPLAIN from QMF too
EXPLAIN ALL SET QUERY NO=1
SELECT * FROM F6417DB.EMPLOYEE
ONce executed successfully u can see theresults by querying the table
yourid.PLAN table by giving the Query number as '1' in predicates.Go thru IBM manuals to understand each columns of PLAN table values and its meanings.
Otherwise go for soem third party tool like File-Aid for Db2 ,Platinum tools etc