Sv: Re: CTE optimization fence

På onsdag 27. juni 2018 kl. 07:45:25, skrev Thomas Kellerer <spam_eater(at)gmx(dot)net
<mailto:spam_eater(at)gmx(dot)net>>:
Tom Lane schrieb am 27.06.2018 um 05:48:
>> I see there was some discussion last year about removing the CTE
>> optimization fence (e.g.
>> http://www.postgresql-archive.org/CTE-inlining-td5958992.html) but can't
>> find anything more recent. Does anyone know if this is still under
>> consideration?
>
> but we have to settle on a way of controlling it.

+1 from me.

I am running more and more into situations where people consider this a bug
rather than a feature.

FWIW, I think a GUC that switches between the current (mostly unwanted, at
least surprising)
way and one where the CTE is optimized together with the main query would
suit "most" people.

For sake of compatibility this could default to the current behaviour
 
+1 from me. The default should be "no fence" for sake of least surprise I
think. Documenting the change would be sufficient.
I hope this will be picked up in the comming V12-cycle.
 
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