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From ramkrishna vasudevan <ramkrishna.s.vasude...@gmail.com>
Subject Re: Scan a region in parallel
Date Fri, 21 Oct 2016 04:00:03 GMT
Hi Anil

So now  you are spawning those many scan threads equal to the number of
regions.
bq.Is there any way to scan a region in parallel ?
You mean with in a region you want to scan parallely? Which means that a
single query you want to split up into N number of small scans and read and
aggregate on the client side/server side?

Currently you cannot do that. Once you set a start and stoprow the scan
will determine which region it belongs to and retrieves the data
sequentially in that region (it applies the filtering that you do during
the course of the scan).

Have you tried Apache Phoenix?  Its a SQL wrapper over HBase and there you
could do parallel scans for a given SQL query if there are some guide posts
collected. Such things cannot be an integral part of HBase. But I fear as I
am not aware of your usecase we cannot suggest on this.

REgards
Ram


On Fri, Oct 21, 2016 at 8:40 AM, Anil <anilklce@gmail.com> wrote:

> Any pointers ?
>
> On 20 October 2016 at 18:15, Anil <anilklce@gmail.com> wrote:
>
> > HI,
> >
> > I am loading hbase table into an in-memory db to support filter, ordering
> > and pagination.
> >
> > I am scanning region and inserting data into in-memory db. each region
> > scan is done in single thread so each region is scanned in parallel.
> >
> > Is there any way to scan a region in parallel ? any pointers would be
> > helpful.
> >
> > Thanks
> >
>

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