Are memory mapped files faster than Named Pipes?

Question

I was reading SQL Server Internals and Troubleshooting (Wrox) and it effectively says that Shared Memory is the default connection method, followed by TCP and then Named Pipes. What's curious though is that they say:

"Named Pipes was developed for local area networks (LANs) but it can be inefficient across slower networks such as wide area networks (WANs)"

I thought named pipes was strictly for IPC? And that in order to jump from IPC to network communication you had to use TCP/UDP. More interesting to me though is the mention of shared memory/memory mapped files - are they faster than NamedPipes/IPC?

Answer 1

The answer is, as usual, "It depends." If there is a lot of data involved, shared memory will cut out much of the overhead of copying it. But using a mapped file in this way still requires some adjunct form of IPC to coordinate access to the shared memory space.