Assigning Plan Volatility Scores to Control Reoptimization Frequency and Number of Stored Reoptimization Plans

Methods, systems, and computer program products are provided for improving the processing of database queries. Some embodiments include generating volatility scores for various plans for executing similar database queries. Different embodiments may utilize: database statistics, the variable values being selected for, and/or historical run time data, to generate the plan volatility scores. In some embodiments, the volatility scores are used to determine whether to generate a new plan for a query, whether to prune an existing plan, and/or how many different plans to store for a query.