calestyo(at)scientia(dot)net writes:
> http://www.postgresql.org/docs/9.1/static/runtime-config-logging.html
> claims that log_filename is only used when logging_collector is enabled.
That is a true statement, as can easily be proven by looking at the
source code: nothing except syslogger.c pays any attention to the
Log_filename variable.
> However it seems that if the later is off, but the former is set (to
> anything), no log output goes to stderr as well.
That would depend on other settings that you haven't mentioned,
particularly log_destination. Keep in mind also that the active setting
of logging_collector can't be changed without a postmaster restart
(which is why it's a separate variable from log_destination).
regards, tom lane