Frank Joerdens <frank(at)joerdens(dot)de> writes:
> What performance penalty can I expect when going over TCP/IP sockets
> instead of Unix sockets?
On a properly designed kernel, there shouldn't be any measurable
performance difference between a local TCP connection and a Unix-socket
connection.
There are not-so-well-designed kernels out there, but I forget which
they are (and you didn't bother to specify your platform anyway).
If you want a reliable answer, fire up a data-transfer-intensive task,
say a COPY OUT of a large table, and time it both ways.
regards, tom lane