Re: Proposed Patch to Improve Performance of Multi-Batch Hash Join for Skewed Data Sets - Mailing list pgsql-hackers

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On Wed, Nov 5, 2008 at 8:20 AM, Tom Lane  wrote:
> Joshua Tolley  writes:
>> On Mon, Oct 20, 2008 at 03:42:49PM -0700, Lawrence, Ramon wrote:
>>> We propose a patch that improves hybrid hash join's performance for large
>>> multi-batch joins where the probe relation has skew.
>
>> I also recommend modifying docs/src/sgml/config.sgml to include the
>> enable_hashjoin_usestatmcvs option.
>
> If the patch is actually a win, why would we bother with such a GUC
> at all?
>
>                        regards, tom lane

Good point. Leaving it in place for patch review purposes is useful,
but we can probably lose it in the end.

- - Josh / eggyknap
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