Abstract: The index optimization (XOP) program is a method to recommend new or improved performance indexes for use by an IBM mainframe DB2 database server for a given set of SQL statements. The recommendations are calculated based on a single call of the DB2 optimizer for each SQL statement with the existing index set, parsing of the SQL statements, the filter factors of the SQL statement predicates, and the getpage workload of an SQL statement. The getpage workload of an SQL statement is the read/change activity on each table and each index currently used for all invocations of an SQL statement. The XOP program computes new and improved performance indexes based on the getpage workload of all relevant SQL statements and does not use the DB2 optimizer to determine the usefulness of potential indexes.