Horton

Re: WIP: Faster Expression Processing and Tuple Deforming (including JIT)

CK Tan <cktan@vitessedata.com>

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From: CK Tan <cktan@vitessedata.com>
To: Andres Freund <andres@anarazel.de>
Cc: Peter Geoghegan <pg@heroku.com>, Pg Hackers <pgsql-hackers@postgresql.org>, Heikki Linnakangas <hlinnaka@iki.fi>, Doug Doole <ddoole@salesforce.com>
Date: 2016-12-13T02:29:42Z
Lists: pgsql-hackers 
On Mon, Dec 12, 2016 at 6:14 PM, Andres Freund <andres@anarazel.de> wrote:
>
>
> For Q1 I think the bigger win is JITing the transition function
> invocation in advance_aggregates/transition_function - that's IIRC where
> the biggest bottleneck lies.
>

Yeah, we bundle the agg core into our expr work... no point otherwise since
we do
it for OLAP.

As for experience, I think you have found out for yourself. There is a lot
that
can be done and heuristics are involved in many places to decide whether
to jit fully, partially, or not at all.  But it looks like you have a solid
basis now
to proceed and explore the beyond :-)

Send me private email if you have a particular question.

Regards,
-cktan

Commits

  1. Improve performance of ExecEvalWholeRowVar.

  2. Remove unreachable code in expression evaluation.

  3. Faster expression evaluation and targetlist projection.

  4. Avoid syntax error on platforms that have neither LOCALE_T nor ICU.

  5. Add configure test to see if the C compiler has gcc-style computed gotos.

  6. Improve regression test coverage for TID scanning.

  7. Improve expression evaluation test coverage.

  8. Fix two errors with nested CASE/WHEN constructs.