| 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: | 2014-06-26 21:48:00 |
| Message-ID: | 53AC9510.9050201@fuzzy.cz |
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| Lists: | Postg토토 커뮤니티SQL |
On 26.6.2014 20:43, Tomas Vondra wrote:
> Attached is v2 of the patch, with some cleanups / minor improvements:
>
> * there's a single FIXME, related to counting tuples in the
Meh, I couldn't resist resolving this FIXME, so attached is v3 of the
patch. This just adds a proper 'batch tuples' counter to the hash table.
All comments, measurements on different queries etc. welcome. We'll
certainly do a lot of testing, because this was a big issue for us.
regards
Tomas
| Attachment | Content-Type | Size |
|---|---|---|
| hashjoin-nbuckets-growth-v3.patch | text/x-diff | 8.5 KB |
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