What is vtable binding?
There are two forms of Early binding. The first and slower method utilizes the Invoke method of the OLE IDispatch interface. The second and faster method utilizes a technique called virtual table (vtable) binding. It uses an offset into a virtual function table to determine what code to call. Calling a vtable-bound method for an in-process OLE server typically requires no more overhead than calling a function in a DLL. What does this mean to you as a Microsoft Office programmer? Almost nothing. This is all taken care of behind the scenes.
