Horton

Re: WIP: Faster Expression Processing v4

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2017-03-21T06:39:29Z
Lists: pgsql-hackers 
On 2017-03-20 16:06:27 -0400, Tom Lane wrote:
> ... is there a reason why resultnum for EEOP_ASSIGN_* steps is declared
> size_t and not just int?  Since it's an array index, and one that
> certainly can't be bigger than AttrNumber, that seems rather confusing.

Not that I can see, no.  I guess I might have "overcompensated" when
changing it from AttrNumber - AttrNumber isn't a good idea because that
needs an extra move-zero-extend, because 16bit indexing isn't that well
supported on x86.  But that doesn't mean it should be a 64bit number -
to the contrary actually.

- Andres

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.