Re: Apply the "LIMIT 1" optimization to partial DISTINCT

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От David Rowley
Тема Re: Apply the "LIMIT 1" optimization to partial DISTINCT
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Msg-id CAApHDvpx2+JEaubSEw75RHvjvjF=g4X3hcty=Tk71Zov9WZ_Dw@mail.gmail.com
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Ответ на Re: Apply the "LIMIT 1" optimization to partial DISTINCT  (David Rowley <dgrowleyml@gmail.com>)
Ответы Re: Apply the "LIMIT 1" optimization to partial DISTINCT  (Richard Guo <guofenglinux@gmail.com>)
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On Fri, 26 Jan 2024 at 21:14, David Rowley <dgrowleyml@gmail.com> wrote:
> However, having said that. Parallel plans are often picked when there
> is some highly selective qual as parallel_tuple_cost has to be applied
> to fewer tuples for such plans, so probably this is worth doing.

I was messing around with your test case and didn't manage to get any
plan that had any rows to use the partial path with the LIMIT.  I
ended up dropping the test that was checking the results were empty as
I didn't think it added much more value over the EXPLAIN output.

I pushed the result.

Thanks for working on this.

David



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