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.

Begin program-specific programming interface information. REOPT(ALWAYS) means that Db2 replaces the value of the host variable with the true value at run time and then determine the access path. REOPT(AUTO) means that Db2 might replace the value of the host variable, depending on how it changed since the last execution.. End program-specific programming interface information.