1. A relational database management system of the type wherein a table function returns a set of result rows which are represented in an SQL statement by a container for the table function, the relational database management system executing on a processor that has access to a storage device and the relational database management system having the improvement comprising: a rewrite method in the storage device, the rewrite method being associated with the table function returning an SQL string which does not include the table function and which when executed will return a set of result rows which is equivalent to the set of result rows returned by the table function, the relational database system executing the rewrite method prior to executing the container to obtain the SQL string and thereupon rewriting the SQL statement such that the container for the table function is replaced by the returned SQL string.