On Sat, May 23, 2020 at 06:33:48PM +0200, Vik Fearing wrote: > > Do we really want default_explain_analyze ? > > It sounds like bad news that EXPLAIN DELETE might or might not remove rows > > depending on the state of a variable. > > I have had sessions where not using ANALYZE was the exception, not the > rule. I would much prefer to type EXPLAIN (ANALYZE OFF) in those cases.
I suggest that such sessions are themselves exceptional. > > I think this should be split into two patches: > > One to make the default explain options configurable, and a separate patch > > to > > change the defaults. > > This patch does not change the defaults, so I'm not sure what you mean here? Sorry, ignore that; I wrote it before digesting the patch. On Sat, May 23, 2020 at 06:16:25PM +0000, Nikolay Samokhvalov wrote: > Not having BUFFERS enabled by default means that in most cases, when asking > for help, people send execution plans without buffers info. I also presumed that's where this patch was going to lead, but it doesn't actually change the default. So doesn't address that, except that if someone reports a performance problem, we can tell them to run: |alter system set explain_buffers=on; SELECT pg_reload_conf() ..which is no better, except that it would also affect any *additional* problem reports which might be made from that cluster. If you want to change the default, I think that should be a separate patch/thread. -- Justin
