1. A method of processing a database query, the method comprising: obtaining a test value set of parameters of one of a user-defined function and a user-defined method, wherein the one of the user-defined function and the user-defined method is included in a database query to be performed on at least one database table of a database, wherein the one user-defined function and the user-defined method is configured to call at least one function to be executed on content of the at least one database table of a database when included in the database query, wherein the test value set comprises input values to the one of the user-defined function and the user-defined method, wherein the test value set is maintained separately from the database; setting parameters of the one of the user-defined function and the user-defined method according to the test value set, wherein the test value set is used exclusively to set the parameters of the one of the user-defined function and the user-defined method; running the one of the user-function and the user-defined method based on the parameters; calculating an execution time of the running of the one of the user-defined function and the user-defined method; storing the execution time of the running of the one of the user-defined function and the user-defined method; receiving the database query; in response to receipt of the database query, creating a query response plan comprising planned execution of the one of the user-defined function and the user-defined method, wherein the stored calculated execution time of the one of the user-defined function and the user-defined method is used in the creation of to determine a cost of the query response plan; and executing the query response plan to generate a response to the database query.