On Thu, 20 Aug 2020 at 03:31, Fujii Masao <masao.fu...@oss.nttdata.com> wrote: > > > > On 2020/08/19 19:39, David Rowley wrote: > > On Wed, 19 Aug 2020 at 21:05, Julien Rouhaud <rjuju...@gmail.com> wrote: > >> > >> On Wed, Aug 19, 2020 at 08:49:48PM +1200, David Rowley wrote: > >>> However, I'm not quite sure how we should handle if someone does: > >>> EXPLAIN (BUFFERS on, SUMMARY off). Without the summary, there's no > >>> place to print the buffers, which seems bad as they asked for buffers. > >> > >> > >> But this won't be as much a problem if ANALYZE is asked, and having > >> different > >> behaviors isn't appealing. So maybe it's better to let people get what > >> they > >> asked for even if that's contradictory? > > > > I'd say BUFFERS on, BUFFERS off is contradictory. I don't think > > BUFFERS, SUMMARY OFF is. It's just that we show the buffer details for > > the planner in the summary. Since "summary" is not exactly a word > > that describes what you're asking EXPLAIN to do, I wouldn't blame > > users if they got confused as to why their BUFFERS on request was not > > displayed. > > Displaying the planner's buffer usage under summary is the root cause of > the confusion? If so, what about displaying that outside summary? > Attached is the POC patch that I'm just thinking.
I had a look at this and I like it better than what I proposed earlier. The change to show_buffer_usage() is a bit ugly, but I'm not really seeing a better way to do it. Perhaps that can be improved later if we ever find that there's some other special case to add. David
