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From Nick Dimiduk <ndimi...@gmail.com>
Subject Re: Timerange scan
Date Sat, 28 Feb 2015 23:25:32 GMT
A Scan without start and end rows will be issued to all regions in the
table -- a full table scan. Within each region, store files will be
selected to participate in the scan based on on the min/max timestamps
from their
headers.

On Saturday, February 28, 2015, Kristoffer Sjögren <stoffe@gmail.com> wrote:

> If Scan.setTimeRange is a full table scan then it runs surprisingly fast on
> tables that host a few hundred million rows :-)
>
>
>
> On Sat, Feb 28, 2015 at 8:05 PM, Kristoffer Sjögren <stoffe@gmail.com
> <javascript:;>>
> wrote:
>
> > Hi Jean-Marc
> >
> > I was thinking of Scan.setTimeRange to only get the x latest rows, but I
> > would like to avoid a full table scan.
> >
> > The alternative would be to use set the timestamp in the key and use
> start
> > and stop key. But since HBase already is aware of timestamps I tought it
> > might optimize Scan.setTimeRange scans?
> >
> > Cheers,
> > -Kristoffer
> >
> > On Sat, Feb 28, 2015 at 7:45 PM, Jean-Marc Spaggiari <
> > jean-marc@spaggiari.org <javascript:;>> wrote:
> >
> >> Hi Kristoffer,
> >>
> >> What do you mean by "timerange scans"? If you want to scan everything
> from
> >> your table, you will always end up with a full table scan, no?
> >>
> >> JM
> >>
> >> 2015-02-28 13:41 GMT-05:00 Kristoffer Sjögren <stoffe@gmail.com
> <javascript:;>>:
> >>
> >> > Hi
> >> >
> >> > I want to understand the effectiveness of timerange scans without
> >> setting
> >> > start and stop keys? Will HBase do a full table scan or will the scan
> be
> >> > optimized in any way?
> >> >
> >> > Cheers,
> >> > -Kristoffer
> >> >
> >>
> >
> >
>

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