Re: bad estimation together with large work_mem generates terrible slow hash joins

From: Tomas Vondra <tv(at)fuzzy(dot)cz>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: bad estimation together with large work_mem generates terrible slow hash joins
Date: 2014-06-30 21:12:14
Message-ID: 53B1D2AE.6010500@fuzzy.cz
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Hi,

attached is v5 of the patch. The main change is that scaling the number
of buckets is done only once, after the initial hash table is build. The
main advantage of this is lower price. This also allowed some cleanup of
unecessary code.

However, this new patch causes warning like this:

WARNING: temporary file leak: File 231 still referenced

I've been eyeballing the code for a while now, but I still fail to see
where this comes from :-( Any ideas?

regards
Tomas

Attachment Content-Type Size
hashjoin-nbuckets-growth-v5-with-guc.patch text/x-diff 11.0 KB

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