Re: Discussion on missing optimizations

Andres Freund wrote:
> On 2017-10-08 11:28:09 -0400, Tom Lane wrote:
> > Adam Brusselback <adambrusselback(at)gmail(dot)com> writes:
> > > On another note:
> > >> turning ORs into UNIONs
> >
> > > This is another one which would be incredibly useful for me. I've had
> > > to do this manually for performance reasons far too often.
> >
> > Well, maybe you could sign up to help review the open patch for that then:
> > https://commitfest.postgresql.org/15/1001/
> >
> > The reason that's not in v10 is we haven't been able to convince
> > ourselves whether it's 100% correct.
>
> Unfortunately it won't help in this specific case (no support for UNION,
> just UNION ALL), but I thought it might be interesting to reference
> https://medium.com/@uwdb/introducing-cosette-527898504bd6
> here.

Interesting. I thought about a completely different approach -- use a
fuzzer, which runs each generated query on two servers, one patched one
not, and compare the results. Would it be possible to tweak sqlsmith to
do this?

--
Álvaro Herrera https://www.2ndQuadrant.com/
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