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From Hubert Zhang <hzh...@pivotal.io>
Subject Re: elastic execution engine question
Date Fri, 01 Jul 2016 01:35:57 GMT
For hash tables, The number of virtual segments is equal to the bucket
number of the table. Bucket number can be specified when creating the table.

On Fri, Jul 1, 2016 at 9:31 AM, Ivan Weng <iweng@pivotal.io> wrote:

> How about hash table?
>
> On Fri, Jul 1, 2016 at 9:30 AM, Hubert Zhang <hzhang@pivotal.io> wrote:
>
> > For random table, the virtual segment number is related to the data size
> of
> > the table. For large tables, we prefer use more virtual segments to
> achieve
> > better performance. While for small tables, less virtual segments are
> > needed, which could save resources and enable more concurrent queries.
> >
> > On Fri, Jul 1, 2016 at 9:22 AM, yanqing weng <wengyanqing@gmail.com>
> > wrote:
> >
> > > Hi HAWQ developer,
> > >
> > > Elastic execution engine is the important feature in HAWQ 2.0.
> > >
> > > I have a question for this feature in the HAWQ debugging. Is there
> > possible
> > > to control the virtual segment number when run query ? If so, which GUC
> > or
> > > parameter I should set ? Thanks.
> > >
> >
> >
> >
> > --
> > Thanks
> >
> > Hubert Zhang
> >
>



-- 
Thanks

Hubert Zhang

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