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

Hi,

On 2018-09-19 20:39:22 -0700, Andres Freund wrote:
> On 2018-09-19 23:26:52 -0400, Tom Lane wrote:
> > 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.

I'm wondering about upper-casing the individual times (and options) -
we're largely upper-casing properties, and for json/xml output each
would still be a property. Seems a tad bit more consistent.  I now have:

FORMAT text:
 JIT:
   Functions: 2
   Options: Inlining true, Optimization true, Expressions true, Deforming true
   Timing: Generation 0.298 ms, Inlining 2.250 ms, Optimization 5.797 ms, Emission 5.246 ms, Total 13.591 ms

FORMAT xml:
     <JIT>
       <Functions>2</Functions>
       <Options>
         <Inlining>true</Inlining>
         <Optimization>true</Optimization>
         <Expressions>true</Expressions>
         <Deforming>true</Deforming>
       </Options>
       <Timing>
         <Generation>0.651</Generation>
         <Inlining>2.260</Inlining>
         <Optimization>14.752</Optimization>
         <Emission>7.764</Emission>
         <Total>25.427</Total>
       </Timing>
     </JIT>

FORMAT json:
     "JIT": {
       "Functions": 2,
       "Options": {
         "Inlining": true,
         "Optimization": true,
         "Expressions": true,
         "Deforming": true
       },
       "Timing": {
         "Generation": 0.238,
         "Inlining": 0.807,
         "Optimization": 4.661,
         "Emission": 4.236,
         "Total": 9.942
       }
     },

>
> > (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.

Now that space is less of a concern, I added expressions, and deforming
as additional options - seems reasonable to have all PGJIT_* options
imo.

Btw, I chose true/false rather than on/off, to be consistent with
ExplainPropertyBool - but I've no strong feelings about it.

Greetings,

Andres Freund