Re: reducing statistics write overhead

Martin Pihlak <martin.pihlak@gmail.com> writes:
> So, as a simple optimization I am proposing that the file should be
> only written when some backend requests statistics. This would
> significantly reduce the undesired write traffic at the cost of
> slightly slower stats access.

How necessary is this given the recent fixes to allow the stats file to
be kept on a ramdisk?

> Attached is a WIP patch, which basically implements this:

This patch breaks deadlock checking and statement_timeout, because
backends already use SIGALRM.  You can't just take over that signal.
It's possible that you could get things to work by treating this as an
additional reason for SIGALRM, but that code is unreasonably complex
already.  I'd suggest finding some other way.
        regards, tom lane