hawq-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Hubert Zhang <hzh...@pivotal.io>
Subject Re: elastic execution engine question
Date Fri, 01 Jul 2016 08:14:08 GMT
This GUC hawq_rm_stmt_nvseg is used by resource manager.
Yi, could you please give some detailed information?

On Fri, Jul 1, 2016 at 12:48 PM, Vineet Goel <vgoel@pivotal.io> wrote:

> What about hawq_rm_stmt_nvseg ?
>
>
> http://hdb.docs.pivotal.io/20/reference/guc/parameter_definitions.html#hawq_rm_stmt_nvseg
>
> -Vineet
>
>
>
> On Jun 30, 2016, at 6:43 PM, Hubert Zhang <hzhang@pivotal.io> wrote:
>
> You can try to the GUC
>
> enforce_virtual_segment_number.
>
> It works for queries without UDF.
>
> On Fri, Jul 1, 2016 at 9:40 AM, yanqing weng <wengyanqing@gmail.com>
> wrote:
>
> > Thanks Hubert.
> >
> > Can it be set only use one virtual segment for the query ? Because this
> > can debug query more easily.
> >
> >
> > On Fri, Jul 1, 2016 at 9:35 AM, Hubert Zhang <hzhang@pivotal.io> wrote:
> >
> >> 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
> >>
> >
> >
>
>
> --
> Thanks
>
> Hubert Zhang
>
>


-- 
Thanks

Hubert Zhang

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message