Re: auto_explain vs. parallel query

On Thu, Nov 3, 2016 at 12:11 PM, Tomas Vondra
<tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
>> Sure, the Gather node creates it. There's generally only one per
>> query, though, and that's how most information is communicated from
>> leader to workers.
>
> Ah, right. I haven't realized there's just a single Gather per query.

That's not a hard and fast rule; it just usually works out that way.

>> Yeah. I thought that there wouldn't be any reason for third-party
>> code to need to get into these segments, but maybe that was
>> short-sighted of me. If we fix this without that, then we've got to
>> force pg_stat_statements to be loaded through
>> shared_preload_libarries, as you mentioned, and that doesn't seem nice
>> either.
>
> Well, I was talking about auto_explain, and pg_stat_statements already has
> to be loaded through shared_preload_libraries. I'm not sure how many other
> extensions would need similar hack (I don't see any in contrib, but there
> may be external ones).

Sorry, auto_explain, then.

--
Robert Haas
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