A method, system and article of manufacture for query execution management in a data processing system and, more particularly, for managing execution of queries including user-defined functions. One embodiment includes an operation for managing execution of a query against data of a database. The operation includes receiving a query against the data of the database, the query having at least one query condition including a user-defined function. It is determined whether the user-defined function satisfies a predefined index applicability criterion. If the user-defined function satisfies the predefined index applicability criterion, an index over relevant data of the database is created for the user-defined function. The index is suitable for use in execution of the query against the data of the database to determine a corresponding query result.