| 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: | 2014-07-20 16:29:34 |
| Message-ID: | 53CBEE6E.8080702@fuzzy.cz |
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| Lists: | pgsql-hackers |
Attached v9 of the patch. Aside from a few minor fixes, the main change
is that this is assumed to be combined with the "dense allocation" patch.
It also rewrites the ExecHashIncreaseNumBuckets to follow the same
pattern as ExecHashIncreaseNumBatches (i.e. scanning chunks directly,
instead of buckets). It's cleaner and more consistent.
hashjoin-nbuckets-growth-v9.patch contains only this patch, so you need
to grab the hashjoin-alloc-v4.patch from a different thread and apply it
first)
hashjoin-nbuckets-growth-v9-combined.patch contains both patches combined
regards
Tomas Vondra
| Attachment | Content-Type | Size |
|---|---|---|
| hashjoin-nbuckets-growth-v9-combined.patch | text/x-diff | 25.1 KB |
| hashjoin-nbuckets-growth-v9.patch | text/x-diff | 17.0 KB |
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