Re: Default gucs for EXPLAIN

On Sun, Aug 02, 2020 at 12:00:56AM +0200, Daniel Gustafsson wrote:
> > On 10 Jul 2020, at 15:30, Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
> >
> > On 2020-05-23 11:14, Vik Fearing wrote:
> >> Here is a patch to provide default gucs for EXPLAIN options.
> >> I have two goals with this patch. The first is that I personally
> >> *always* want BUFFERS turned on, so this would allow me to do it without
> >> typing it every time.
> >
> > There was a lot of opposition to the approach taken by this patch, but there was a lot of support turning BUFFERS on by default. Would you like to submit a patch for that?
>
> My reading of this thread and the above that the patch, and CF entry, as it
> stands should be rejected - but that a separate patch for turning BUFFERS on by
> default would be highly appreciated. Unless objections I'll go do that in the
> CF app for 2020-07.

Sounds right. I have a patch to enable buffers by default, but that raises the
issue about how to avoid machine-dependent output when we run explain ANALYZE.
One option is to add "buffers off" to the existing incantation of (COSTS OFF,
TIMING OFF, SUMMARY OFF). But I think we should just add a new "REGRESS"
option, which does that and any future similar thing (like WAL OFF).

I have a patch to do that, too, which I included in an early version of this
series (which I since changed to run explain without analyze). That handles
most but not all machine-dependant output.
https://www.postgresql.org/message-id/20200306213310.GM684%40telsasoft.com

--
Justin