Re: WIP: Faster Expression Processing v4

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>

To: Heikki Linnakangas <hlinnaka@iki.fi>

Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers@postgresql.org

Date: 2017-03-14T22:47:06Z

Lists: pgsql-hackers

Attachments

0001-Add-expression-dependencies-on-composite-type-whole-.patch.gz (application/x-patch-gzip) patch 0001
0002-Make-get_last_attnums-more-generic.patch.gz (application/x-patch-gzip) patch 0002
0003-Add-configure-test-for-computed-goto-support.patch.gz (application/x-patch-gzip) patch 0003
0004-Faster-expression-evaluation-and-targetlist-projecti.patch.gz (application/x-patch-gzip) patch 0004

Hi,

On 2017-03-14 16:58:54 +0200, Heikki Linnakangas wrote:
> * execInterpExpr.c is quite a mouthful. How about exprInterpreter.c?

I applied most of your changes in the attached version.

Notes:
* I quite like how the EEO_JUMP/EEO_NEXT stuff looks now / after your
  change, that's clearly better.
* I reverted the removal of EEO_SWITCH() - pgindent goes a bit bonkers
  if it can see the switch(), but not the case: statements.
* I re-added ExecEvalStepOp() - for one it's hugely useful during
  debugging, for another I'm actually using it in a follow patch (So JIT
  compilation can run after the interpreter has been initialized).
  Added code guaranteeing that we can't run
  ExecInstantiateInterpretedExpr() twice.
* Renamed EEO_* opcode enum members to EEOP_* as suggested
* I've not yet renamed execInterpExpr.c - I don't like execInterpreter.c
  because it doesn't reference expressions and execExprInterpreter.c
  seems a bit long - but I can live with both (preferring the
  latter). Not that surprisingly I can also live with execInterpExpr.c ;)
* Addressed your size_t sizing concern by using, as is proper anyway,
  intptr_t.
* I tried to clarify the comment in execExpr.c's header that you marked
  as hard to understand.

Greetings,

Andres Freund

Commits

Improve performance of ExecEvalWholeRowVar.
- 2f0903ea1965 10.0 landed
Remove unreachable code in expression evaluation.
- ad46a2aa79f9 10.0 landed
Faster expression evaluation and targetlist projection.
- b8d7f053c5c2 10.0 landed
Avoid syntax error on platforms that have neither LOCALE_T nor ICU.
- 457a44487328 10.0 cited
Add configure test to see if the C compiler has gcc-style computed gotos.
- bc18126a6bcb 10.0 landed
Improve regression test coverage for TID scanning.
- be6c3d19fd45 10.0 landed
Improve expression evaluation test coverage.
- ce38949ba23a 10.0 landed
Fix two errors with nested CASE/WHEN constructs.
- f0c7b789ab12 9.6.0 cited