> On Aug 22, 2018, at 2:58 PM, Andreas Joseph Krogh <andr...@visena.com> wrote: > > På onsdag 22. august 2018 kl. 20:52:05, skrev Andres Freund > <and...@anarazel.de <mailto:and...@anarazel.de>>: > On 2018-08-22 19:51:12 +0200, Andreas Joseph Krogh wrote: > > I thought JITing of prepared queries happended once (in "prepare") > > No, it happens when the first JITed function is executed. > > > > so it didn't have to do the JITing every time the query is > > executed. Isn't the previously generated bytecode usable for > > subsequent queries? > > No, not currently. There's some reasons preventing that (primarily that > we currently rely on addresses of certain things not to change during > execution). There's ongoing work to change that, but that's certainly > not going to be ready for v11. > > Greetings, > > Andres Freund > > > Ok, thanks for clarifying.
Per earlier note[1] I was able to reproduce this issue with similar results to Andreas while running 11 Beta 3. jit = on https://explain.depesz.com/s/vgzD <https://explain.depesz.com/s/vgzD> Planning Time: 0.921 ms JIT: Functions: 193 Generation Time: 121.595 ms Inlining: false Inlining Time: 0.000 ms Optimization: false Optimization Time: 58.045 ms Emission Time: 1201.100 ms Execution Time: 1628.017 ms jit = off https://explain.depesz.com/s/AvZM <https://explain.depesz.com/s/AvZM> Planning Time: 1.398 ms Execution Time: 256.473 ms I increased the the search range I used in the query by 3x, and got these numbers: jit=on Planning Time: 0.931 ms JIT: Functions: 184 Generation Time: 126.587 ms Inlining: true Inlining Time: 98.865 ms Optimization: true Optimization Time: 20518.982 ms Emission Time: 7270.963 ms Execution Time: 28772.576 ms jit=off Planning Time: 1.527 ms Execution Time: 959.160 ms So, I would +1 this for open items. Jonathan [1] https://www.postgresql.org/message-id/7F838324-064B-4A24-952C-2800CFBD39D6%40postgresql.org <https://www.postgresql.org/message-id/7f838324-064b-4a24-952c-2800cfbd3...@postgresql.org>
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