Re: Query is over 2x slower with jit=on

čt 20. 9. 2018 v 5:39 odesílatel Andres Freund <andres@anarazel.de> napsal:

> On 2018-09-19 23:26:52 -0400, Tom Lane wrote:
> > Andres Freund <andres@anarazel.de> writes:
> > > On 2018-09-17 17:50:15 -0400, Tom Lane wrote:
> > >> Just to throw a contrarian opinion into this: I find the current
> EXPLAIN
> > >> output for JIT to be insanely verbose already.
> >
> > > Hm, it'd have been nice to get that feedback a little bit earlier, I
> did
> > > inquire...
> >
> > > Currently:
> >
> > > JIT:
> > >   Functions: 2
> > >   Generation Time: 0.680 ms
> > >   Inlining: true
> > >   Inlining Time: 7.591 ms
> > >   Optimization: true
> > >   Optimization Time: 20.522 ms
> > >   Emission Time: 14.607 ms
> >
> > Just to clarify, that seems perfectly fine for the "machine readable"
> > output formats.  I'd just like fewer lines in the "human readable"
> > output.
>
> Yea, I do think that's a fair complaint.
>
>
> > > How about making that:
> >
> > > JIT:
> > >   Functions: 2
>
> FWIW, not that I want to do that now, but at some point it might make
> sense to sub-divide this into things like number of "expressions",
> "tuple deforming", "plans", ...  Just mentioning that if somebody wants
> to comment on reformatting this as well, if we're tinkering anyway.
>
>
> > >   Options: Inlining, Optimization
> > >   Times (Total, Generation, Inlining, Optimization, Emission): 43.4
> ms, 0.680 ms, 7.591 ms, 20.522 ms, 14.607 ms
>

+1

Pavel


> >
> > > or something similar?
> >
> > That's going in the right direction.  Personally I'd make the last line
> > more like
> >
> >     Times: generation 0.680 ms, inlining 7.591 ms, optimization 20.522
> ms, emission 14.607 ms, total 43.4 ms
>
> Yea, that's probably easier to read.
>
>
> > (total at the end seems more natural to me, YMMV).
>
> I kind of think doing it first is best, because that's usually the first
> thing one wants to know.
>
>
> > Also, the "options" format you suggest here seems a bit too biased
> > towards binary on/off options --- what happens when there's a
> > three-way option?  So maybe that line should be like
> >
> >     Options: inlining on, optimization on
> >
> > though I'm less sure about that part.
>
> I'm pretty certain you're right :).  There's already arguments around
> making optimization more gradual (akin to O1,2,3).
>
> Greetings,
>
> Andres Freund
>
>