Re: A better way than tweaking NTUP_PER_BUCKET

On 27 January 2014 17:44, Pavel Stehule <pavel.stehule@gmail.com> wrote:

> This topic is interesting - we found very bad performance with hashing large
> tables with high work_mem. MergeJoin with quicksort was significantly
> faster.

I've seen this also.

> I didn't deeper research - there is a possibility of virtualization
> overhead.

I took measurements and the effect was repeatable and happened for all
sizes of work_mem, but nothing more to add.

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