Interpreting data access by using EXPLAIN
You can use the values captured in EXPLAIN tables, and instances of PLAN_TABLE in particular, to analyze how Db2 accesses data when it processes a particular SQL statement.
Tip: 
You can generate diagrams of the access paths used for your SQL statements by using the visual explain capability in tools such as IBM® Db2 Administration Foundation for z/OS® and IBM Db2 for z/OS Developer Extension.
You can generate diagrams of the access paths used for your SQL statements by using the visual explain capability in tools such as IBM® Db2 Administration Foundation for z/OS® and IBM Db2 for z/OS Developer Extension.