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Re: Additional size of hash table is alway zero for hash aggregates - Mailing list pgsql-hackers

From Pengzhou Tang
Subject Re: Additional size of hash table is alway zero for hash aggregates
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Msg-id CAG4reAQaiwoCr7QFPwHxR3CbQaLT_71cLP6kpF+ESc4GT4WWfA@mail.gmail.com
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In response to Re: Additional size of hash table is alway zero for hash aggregates  (Andres Freund <andres@anarazel.de>)
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On 2020-03-12 16:35:15 +0800, Pengzhou Tang wrote:
> When reading the grouping sets codes, I find that the additional size of
> the hash table for hash aggregates is always zero, this seems to be
> incorrect to me, attached a patch to fix it, please help to check.

Indeed, that's incorrect. Causes the number of buckets for the hashtable
to be set higher - the size is just used for that.  I'm a bit wary of
changing this in the stable branches - could cause performance changes?


 thanks for confirming this. 

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