An Access Plan is built automatically by the operating system. Each time an SQL request runs, the system tries to determine the best method for fullfilling the request. Attempting to find the optimum performance for a request can be thought of as the "building of an access plan". An important performance issue is whether the Access Plan gets reused or rebuilt each time a request runs. Static SQL versus dynamic SQL plays a huge role.

Access Paths are indexes or logical views that are stored on the system for providing data in a predefined sequence. Efficient use of prebuilt indexes or Access Paths is critical to optimizing SQL performance on your systems. The ability of SQL to quickly subset data via an index will have a direct effect on your application's SQL performance.