Compiling code at run-time (compile-time execution) gives you the capability to execute dynamic procedures that execute queries and other immediate compile-and-run-related activities. (Although, with Version 9, you are more likely to use dynamic queries than dynamic procedures to execute immediate queries.) Compile-time execution can be an asset while developing an application, but a security issue when deploying, if other safeguards are not provided to protect the source code.
If an application is deployed using runtime compilation, ensure that your security framework is tightly defined so that your other security efforts cannot be violated. For example, you should ensure that all source files are appropriately secured at the operating-system level.