Horton

Re: WIP: Faster Expression Processing v4

Tomas Vondra <tomas.vondra@2ndquadrant.com>

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From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: pgsql-hackers@postgresql.org
Date: 2017-03-12T04:40:51Z
Lists: pgsql-hackers 
Hi,

On 03/07/2017 04:01 AM, Andres Freund wrote:
> Hi,
>
> Attached is an updated version of the patchset, but more importantly
> some benchmark numbers.
>

I wanted to do a bit of testing and benchmarking on this, but 0004 seems 
to be a bit broken. The patch does not apply anymore - there are some 
conflicts in execQual.c, but I think I fixed those. But then I ran into 
a bunch of compile-time errors, because some of the executor nodes still 
reference bits that were moved elsewhere.

E.g. there's no targetlist in PlanState anymore, yet nodeGatherMerge and 
nodeTableFuncscan do this:

	gm_state->ps.targetlist = (List *)
		ExecInitExpr((Expr *) node->plan.targetlist,
					 (PlanState *) gm_state);

Some of the nodes also assign to ps.qual values that are (List *), but 
that field was switched to ExprState. That needs fixing, I guess.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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.