A database engine and optimizer framework includes a decoder to identify and process SQL queries or statements that reference a UDF before they are executed. Once such a statement is detected, the decoder determines if the UDF is capable of being merged into an SQL statement and, if so, performs such a merge. In some embodiments, the decoder may not use a pre-cached version of the UDF but, instead, may include a component that locates and retrieves the latest version of the UDF for use when performing the merge. Also, for UDFs that cannot easily be merged into an SQL statement, the decoder may not merge the UDF into an SQL statement but may allow the optimizer and execution engine to retrieve and execute the UDF in the usual manner.