Horton

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

Andreas Joseph Krogh <andreas@visena.com>

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From: Andreas Joseph Krogh <andreas@visena.com>
To: Andres Freund <andres@anarazel.de>
Cc: Robert Haas <robertmhaas@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, "Jonathan S. Katz" <jkatz@postgresql.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-08-22T18:58:45Z
Lists: pgsql-hackers 
På onsdag 22. august 2018 kl. 20:52:05, skrev Andres Freund <andres@anarazel.de 
<mailto:andres@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.
 
--
 Andreas Joseph Krogh

Commits

  1. Fix issues around EXPLAIN with JIT.

  2. Collect JIT instrumentation from workers.

  3. Make EXPLAIN output for JIT compilation more dense.

  4. Save/restore SPI's global variables in SPI_connect() and SPI_finish().

  5. Rationalize handling of single and double quotes in bootstrap data.