The steps you take to develop, compile, install, and invoke an external stored procedure depend on whether the external stored procedure issues operating system I/O calls and whether the external stored procedure executes SQL. The meaning of I/O as it applies to external stored procedures is any operating system call that requires the operating system to retain a resource context, such as for open files or other operating system services. Such resource usage usually returns a handle to the caller that is used to access the resource and must be released when finished using it.
The next few pages provide high level overviews of the steps you take to develop external stored procedures. You can find details for each step in the following sections.