generation_counter includes time spent on both JIT:ing expressions
and tuple deforming which are configured independently via options
jit_expressions and jit_tuple_deforming. As they are combined in
the same counter it's not apparent what fraction of time the tuple
deforming takes.
This adds deform_counter dedicated to tuple deforming, which allows
seeing more directly the influence jit_tuple_deforming is having on
the query. The counter is exposed in EXPLAIN and pg_stat_statements
bumpin pg_stat_statements to 1.11.
Author: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/20220612091253.eegstkufdsu4kfls@erthalion.local
In one or two places it seemed reasonable to modify the example so as
to shorten its output slightly; but for the most part I just added a
&zwsp; after 67 characters, which is the most we can fit on a line
of monospace text in A4 format.
Discussion: https://postgr.es/m/6916.1589146280@sss.pgh.pa.us
I (Andres) was more than a bit hasty in committing 33001fd7a7072d48327
after last minute changes, leading to a number of problems (jit output
was only shown for JIT in parallel workers, and just EXPLAIN without
ANALYZE didn't work). Lukas luckily found these issues quickly.
Instead of combining instrumentation in in standard_ExecutorEnd(), do
so on demand in the new ExplainPrintJITSummary().
Also update a documentation example of the JIT output, changed in
52050ad8ebec8d831.
Author: Lukas Fittl, with minor changes by me
Discussion: https://postgr.es/m/CAP53PkxmgJht69pabxBXJBM+0oc6kf3KHMborLP7H2ouJ0CCtQ@mail.gmail.com
Backpatch: 11, where JIT compilation was introduced
Per discussion, JIT isn't quite mature enough to ship enabled-by-default.
I failed to resist the temptation to do a bunch of copy-editing on the
related documentation. Also, clean up some inconsistencies in which
section of config.sgml the JIT GUCs are documented in vs. what guc.c
and postgresql.config.sample had.
Discussion: https://postgr.es/m/20180914222657.mw25esrzbcnu6qlu@alap3.anarazel.de
An xref to a <para>'s ID isn't very helpful because paras don't have
names. This causes a warning while building PDFs, though for some
reason not while building HTML. The link arguably went to the wrong
place, too.
To fix, introduce a sub-section we can reference.
As promised in earlier commits, this adds documentation about the new
build options, the new GUCs, about the planner logic when JIT is used,
and the benefits of JIT in general.
Also adds a more implementation oriented README.
I'm sure we're going to want to expand this further, but I think this
is a reasonable start.
Author: Andres Freund, with contributions by Thomas Munro
Reviewed-By: Thomas Munro
Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de
