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

On April 18, 2018 12:16:35 PM PDT, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>On Wed, Apr 18, 2018 at 11:50 AM, Andres Freund <andres(at)anarazel(dot)de>
>wrote:
>> JIT has cost, and sometimes it's not beneficial. Here our heuristics
>> when to JIT appear to be a bit off. In the parallel world it's worse
>> because the JITing is duplicated for parallel workers atm.
>
>It seems like you're describing it as if the JIT just didn't produce
>gains sufficient to make up for the cost of doing it, but that's not
>really the issue here AFAICS. Here the JIT actually made code that
>run slower than the un-JIT-ted code. That seems like a different sort
>of problem.

Not convinced that that is true - the issue is more likely that JIT work in workers is counted as execute time... Gotta add that somehow, not sure what the best way would be.
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