On Thu, Apr 02, 2020 at 01:05:56PM +0900, Fujii Masao wrote:
>
>
> On 2020/04/02 3:47, Julien Rouhaud wrote:
> > On Wed, Apr 1, 2020 at 7:51 PM Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com> wrote:
> > >
> > >
> > > On 2020/03/31 10:31, Justin Pryzby wrote:
> > > > On Wed, Jan 29, 2020 at 12:15:59PM +0100, Julien Rouhaud wrote:
> > > > > Rebase due to conflict with 3ec20c7091e97.
> > > >
> > > > This is failing to apply probably since 4a539a25ebfc48329fd656a95f3c1eb2cda38af3.
> > > > Could you rebase? (Also, not sure if this can be set as RFC?)
> > >
> > > I updated the patch. Attached.
> >
> > Thanks a lot! I'm sorry I missed Justin's ping, and it I just
> > realized that my cron job that used to warn me about cfbot failure was
> > broken :(
> >
> > > +/* Compute the difference between two BufferUsage */
> > > +BufferUsage
> > > +ComputeBufferCounters(BufferUsage *start, BufferUsage *stop)
> > >
> > > Since BufferUsageAccumDiff() was exported, ComputeBufferCounters() is
> > > no longer necessary. In the patched version, BufferUsageAccumDiff() is
> > > used to calculate the difference of buffer usage.
> >
> > Indeed, exposing BufferUsageAccumDiff wa definitely a good thing!
> >
> > > + if (es->summary && (planduration || es->buffers))
> > > + ExplainOpenGroup("Planning", "Planning", true, es);
> > >
> > > Isn't it more appropriate to check "bufusage" instead of "es->buffers" here?
> > > The patch changes the code so that "bufusage" is checked.
> >
> > AFAICS not unless ExplainOneQuery is also changed to pass a NULL
> > pointer if the BUFFER option wasn't provided (and maybe also
> > optionally skip the planning buffer computation). With this version
> > you now get:
> >
> > =# explain (analyze, buffers off) update t1 set id = id;
> > QUERY PLAN
> > -------------------------------------------------------------------------------------------------------
> > Update on t1 (cost=0.00..22.70 rows=1270 width=42) (actual
> > time=0.170..0.170 rows=0 loops=1)
> > -> Seq Scan on t1 (cost=0.00..22.70 rows=1270 width=42) (actual
> > time=0.050..0.054 rows=1 loops=1)
> > Planning Time: 1.461 ms
> > Buffers: shared hit=25
> > Execution Time: 1.071 ms
> > (5 rows)
> >
> > which seems wrong to me.
> >
> > I reused the es->buffers to avoid having needing something like:
>
> Yes, you're right! So I updated the patch as you suggested.
> Attached is the updated version of the patch.
> Thanks for the review!
Thanks a lot, it all looks good to me!