Horton

Re: WIP: Faster Expression Processing v4

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2017-03-15T03:23:48Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> On 2017-03-14 19:34:12 -0400, Tom Lane wrote:
>> It seems bizarre that you chose to spell the new configure symbol as
>> HAVE__COMPUTED_GOTO rather than HAVE_COMPUTED_GOTO

> I went back-and-forth about this a number of times.  We have a bunch of
> symbols defined with HAVE__ as a prefix (and some with HAVE_GCC__) - and
> more of the nearby code seems to use __ rather than _.  I don't really
> know why we started doing that, but it's far from new..

> Any idea why we introduce __ stuff?

The nearby stuff is describing features that have a specific name that
includes a leading underscore or two, like __builtin_unreachable().
That doesn't seem to apply here, so I wouldn't add extra underscores.

			regards, tom lane

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.