Matthew Hagerty <matthew(at)venux(dot)net> writes:
> Does pg open its logfile every time it writes or does it open the file and
> hold it open as long as the postmaster is running?
If you do the usual
postmaster >logfile 2>&1
then the logfile is actually opened by the shell before the postmaster
ever starts; the postmaster has no way to close and re-open it. So,
no, you can't rotate the logfile transparently in that scenario.
I believe there's a compile-time option to use syslog instead, which
probably works better for this (assuming you have syslog).
regards, tom lane