A method, computer program product and computing device for promoting
reuse of previously generated access plans are disclosed. SQL statements
containing literals are amended so as to substitute a parameter marker
for each literal. Amended statements are provided to the DBMS along with
parameters including the substituted literals and a substitution
indicator indicating that the substitution has been performed. The DBMS
assesses the soundness of the substitutions that are performed. Soundness
may be measured in terms of the semantic correctness of the amended
statement and the likelihood that the literal substitution will improve
DBMS efficiency. If a substitution is unsound, the DBMS may obtain and
optimize the original version of the amended SQL statement. Otherwise,
the amended statement is optimized. Advantageously, SQL statements
originally differing only in the value of one or more literals may become
functionally equivalent, and the reuse of cached, previously generated
access plans is thus promoted.