Capturing EXPLAIN information with QMF

You can use QMF™ to display the results of EXPLAIN to the terminal.

About this task

Begin program-specific programming interface information.
You can create your own form to display the output or use the default form for QMF.
End program-specific programming interface information.

  • Parameter markers in place of host variables
    If you have host variables in a predicate for an original query in a static application and if you are using QMF or SPUFI to execute EXPLAIN for the query, you should consider using parameter markers where you use host variables in the original query.
  • When to use a constant
    If you know that a static plan or package was bound with REOPT(ALWAYS) or REOPT(AUTO) and you have some idea of what is returned in the host variable, including the constant in the QMF EXPLAIN results can be more accurate.
  • Access path differences for static and dynamic SQL statements
    Even when parameter markers are used, the access paths for static and dynamic queries might differ.
Parent topic: Investigating SQL performance by using EXPLAIN