I have 1 physical machine with 2 VMs (VMWare esxi) - one for database (PostgreSQL 9.2.1), and one for application. I'd like my application to connect to my database in an efficient way, and I've heard that using a file system socket is more efficient than a network socket (TCP overhead, IIRC).
- Is there a way to use a file system socket with the aforementioned setup? Or...
- Is there another, efficient connection method you'd recommend?
No, file system sockets (formally Unix Domain Sockets) only work within the same operating system (and while it's technically true that they're more efficient than network sockets, it's a pretty small difference unless you're sending tons of tiny requests).
TCP should work just fine here. If it doesn't after some testing, worry about it then. If you do have problems, they're more likely due to poor query design than the communication protocol between the application and server.