1. A computer program product for facilitating processing within a computing environment, said computer program product comprising: a computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: executing a function using a first execution path; obtaining the function to be executed a next time; determining, based on obtaining the function, whether the first execution path is to be used to execute the function the next time, comprising: checking whether use of a result cache associated with the function is effective; and choosing not to use the first execution path based on the checking indicating use of the result cache is ineffective; automatically switching to a second execution path, based on determining the first execution path is not to be used, wherein the first execution path and the second execution path are supported automatically absent external changes, and wherein the automatically switching to the second execution path occurs absent external changes of internal control structures; and executing the function using the second execution path, based on automatically switching to the second execution path, wherein the first execution path and the second execution path are determined at preparation time of code that includes the function, wherein the function is a user-defined function, the first execution path uses caching and the second execution path uses inlining.