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From Vamshi Krishna <vamshi2...@gmail.com>
Subject Re: how get() works
Date Wed, 15 Feb 2012 15:11:22 GMT
Thank you for your reply Doug.. that is what i wanted to know.

On Tue, Feb 14, 2012 at 9:39 PM, Doug Meil <doug.meil@explorysmedical.com>wrote:

>
> I say "basically" because inside a Region there are Stores, and for each
> Store there are StoreFiles.  For more info see:
>
> http://hbase.apache.org/book.html#regions.arch
>
>
>
>
>
> On 2/14/12 11:06 AM, "Doug Meil" <doug.meil@explorysmedical.com> wrote:
>
> >
> >Keys are stored in sorted order, it's basically a binary search.
> >
> >
> >
> >
> >On 2/14/12 9:31 AM, "Vamshi Krishna" <vamshi2105@gmail.com> wrote:
> >
> >>Thank you Doug..
> >>
> >>Onemore question is, If a particular region is found by looking at the
> >>range handeled by it, How  is search performed within that region to find
> >>requested rowKey? Is it by linear search or binary search or any other
> >>algorithm? Or for every row in that region, is there any hash value
> >>stored
> >>and hash lookup takes place to get that rowKey's value?   what happens
> >>really within that region?
> >>
> >>On Mon, Feb 13, 2012 at 7:35 PM, Doug Meil
> >><doug.meil@explorysmedical.com>wrote:
> >>
> >>>
> >>> re:  "Now if that RegionServer has multiple
> >>> regions on it, how does the request get transfered to a correct region
> >>> which has the requested rowKey?"
> >>>
> >>> See...
> >>>
> >>>
> >>>
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.ht
> >>>m
> >>>l#
> >>> getRegionLocation%28byte[],%20boolean%29
> >>>
> >>> As described in Arch/Client in the book, the Hbase client knows all the
> >>> regions and the the region boundaries from META.
> >>>
> >>>
> >>>
> >>>
> >>> On 2/13/12 1:46 AM, "Vamshi Krishna" <vamshi2105@gmail.com> wrote:
> >>>
> >>> >Hi all, i have a small basic doubt regarding get() method which is
> >>>used in
> >>> >HTable. From the hbase book, under 8.3.Client section, i understood
> >>>that,
> >>> >when ever client sends a request like get(rowKey) on any htable
> >>>instance,
> >>> >from ROOT and META, it knows the regionserver where the regions
> >>>holding
> >>> >that requested rowKey is present. Now if that RegionServer has
> >>>multiple
> >>> >regions on it, how does the request get transfered to a correct region
> >>> >which has the requested rowKey? (will there be again any lookups for
> >>>it?)
> >>> >
> >>> >Is it like this:  The RegionServer holds the information about all the
> >>> >regions it is hosting, so looking at the respective ranges of rows in
> >>>each
> >>> >region a region is selected, and passing that request to that
> >>>appropriate
> >>> >region.  Am i correct? if not, correct me.
> >>> >
> >>> >Onemore question is, If a particular region is found by looking at the
> >>> >range handeled by it, How  is search performed within that region to
> >>>find
> >>> >requested rowKey? Is it by linear search or binary search or any other
> >>> >algorithm? Or for every row in that region, is there any hash value
> >>>stored
> >>> >and hash lookup takes place to get that rowKey's value?   what happens
> >>> >really within that region?
> >>> >
> >>> >
> >>> >can anybody help, please..
> >>> >--
> >>> >*Regards*
> >>> >*
> >>> >Vamshi Krishna
> >>> >*
> >>>
> >>>
> >>>
> >>
> >>
> >>--
> >>*Regards*
> >>*
> >>Vamshi Krishna
> >>*
> >
> >
> >
>
>
>


-- 
*Regards*
*
Vamshi Krishna
*

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