An input is accessed representing a tuning parameter for a first query statement and a tolerance level. The tolerance level represents a degree of acceptable discrepancy between the first query statement and another query statement. A first fingerprint is generated for the first query statement based on a content of the first query statement and the tolerance level; and the first fingerprint and the tuning parameter are stored. The first fingerprint is used as an index for an optimizer to associate the tuning parameter with a second query statement that corresponds to the first fingerprint.