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Posted to user@hbase.apache.org by Ted Yu <yu...@gmail.com> on 2012/12/01 02:20:55 UTC
Re: Why InternalScanner doesn't have a method that returns entire row
or object of Result
Right.
Take a look at AggregateImplementation.getAvg(), you would see how the
following method is used.
On Fri, Nov 30, 2012 at 1:53 PM, anil gupta <an...@gmail.com> wrote:
> Does this method in InternalScanner gets KeyValue's for only 1 row in 1
> call. Am i right?
>
> boolean *next<
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/regionserver/InternalScanner.html#next%28java.util.List%29
> >
> *(List<
> http://download.oracle.com/javase/6/docs/api/java/util/List.html?is-external=true
> >
> <KeyValue<
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/KeyValue.html>
> > results)
> Grab the next row's worth of values.
>
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/regionserver/InternalScanner.html
>
> Thanks,
> Anil Gupta
>
> On Fri, Nov 30, 2012 at 10:54 AM, anil gupta <an...@gmail.com>
> wrote:
>
> > Hi All,
> >
> > I am developing a Coprocessor to sort results on the basis of Cell Value.
> > Basically an equivalent of order by clause in RDBMS.
> > In my subclass of BaseEndpointCoprocessor i would like to do fetch of
> > entire rows rather than individual KeyValue using the InternalScanner.
> But,
> > surprisingly there is no method to do that. Can any one tell me why we
> dont
> > have a method for fetching rows? What is the most optimized way to fetch
> > rows through current InternalScanner methods?
> > --
> > Thanks & Regards,
> > Anil Gupta
> >
>
>
>
> --
> Thanks & Regards,
> Anil Gupta
>
RE: Why InternalScanner doesn't have a method that returns entire
row or object of Result
Posted by Anoop Sam John <an...@huawei.com>.
Asaf
You are correct!
You mean the RegionScanner I think.. The 'limit' is applied at this level. HRegion$RegionScannerImpl
-Anoop-
________________________________________
From: Asaf Mesika [asaf.mesika@gmail.com]
Sent: Thursday, March 07, 2013 6:04 PM
To: user@hbase.apache.org
Subject: Re: Why InternalScanner doesn't have a method that returns entire row or object of Result
Guys,
Just to make things clear:
if I have a row which have 12 keys values, and then another row with 5 KVs,
and I called InternelScanner(results, 10), where 10 is the limit, then I
would get:
1. 10 KV of the 1st row
2. 2 KV of the 1st row
3. 5 KV of the 2nd row
Is this correct?
On Sat, Dec 1, 2012 at 4:01 AM, anil gupta <an...@gmail.com> wrote:
> Hi Ted,
>
> I figured out that i have to use next from InternalScanner. Thanks for the
> response.
> The comment for method "Grab the next row's worth of values." was a little
> confusing to me.
> "Get the keyValue's for the next row" would have been better. Just
> saying....
>
> Thanks,
> Anil
>
> On Fri, Nov 30, 2012 at 5:20 PM, Ted Yu <yu...@gmail.com> wrote:
>
> > Right.
> >
> > Take a look at AggregateImplementation.getAvg(), you would see how the
> > following method is used.
> >
> > On Fri, Nov 30, 2012 at 1:53 PM, anil gupta <an...@gmail.com>
> wrote:
> >
> > > Does this method in InternalScanner gets KeyValue's for only 1 row in 1
> > > call. Am i right?
> > >
> > > boolean *next<
> > >
> >
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/regionserver/InternalScanner.html#next%28java.util.List%29
> > > >
> > > *(List<
> > >
> >
> http://download.oracle.com/javase/6/docs/api/java/util/List.html?is-external=true
> > > >
> > > <KeyValue<
> > > http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/KeyValue.html>
> > > > results)
> > > Grab the next row's worth of values.
> > >
> > >
> >
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/regionserver/InternalScanner.html
> > >
> > > Thanks,
> > > Anil Gupta
> > >
> > > On Fri, Nov 30, 2012 at 10:54 AM, anil gupta <an...@gmail.com>
> > > wrote:
> > >
> > > > Hi All,
> > > >
> > > > I am developing a Coprocessor to sort results on the basis of Cell
> > Value.
> > > > Basically an equivalent of order by clause in RDBMS.
> > > > In my subclass of BaseEndpointCoprocessor i would like to do fetch of
> > > > entire rows rather than individual KeyValue using the
> InternalScanner.
> > > But,
> > > > surprisingly there is no method to do that. Can any one tell me why
> we
> > > dont
> > > > have a method for fetching rows? What is the most optimized way to
> > fetch
> > > > rows through current InternalScanner methods?
> > > > --
> > > > Thanks & Regards,
> > > > Anil Gupta
> > > >
> > >
> > >
> > >
> > > --
> > > Thanks & Regards,
> > > Anil Gupta
> > >
> >
>
>
>
> --
> Thanks & Regards,
> Anil Gupta
>
Re: Why InternalScanner doesn't have a method that returns entire row
or object of Result
Posted by Asaf Mesika <as...@gmail.com>.
Guys,
Just to make things clear:
if I have a row which have 12 keys values, and then another row with 5 KVs,
and I called InternelScanner(results, 10), where 10 is the limit, then I
would get:
1. 10 KV of the 1st row
2. 2 KV of the 1st row
3. 5 KV of the 2nd row
Is this correct?
On Sat, Dec 1, 2012 at 4:01 AM, anil gupta <an...@gmail.com> wrote:
> Hi Ted,
>
> I figured out that i have to use next from InternalScanner. Thanks for the
> response.
> The comment for method "Grab the next row's worth of values." was a little
> confusing to me.
> "Get the keyValue's for the next row" would have been better. Just
> saying....
>
> Thanks,
> Anil
>
> On Fri, Nov 30, 2012 at 5:20 PM, Ted Yu <yu...@gmail.com> wrote:
>
> > Right.
> >
> > Take a look at AggregateImplementation.getAvg(), you would see how the
> > following method is used.
> >
> > On Fri, Nov 30, 2012 at 1:53 PM, anil gupta <an...@gmail.com>
> wrote:
> >
> > > Does this method in InternalScanner gets KeyValue's for only 1 row in 1
> > > call. Am i right?
> > >
> > > boolean *next<
> > >
> >
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/regionserver/InternalScanner.html#next%28java.util.List%29
> > > >
> > > *(List<
> > >
> >
> http://download.oracle.com/javase/6/docs/api/java/util/List.html?is-external=true
> > > >
> > > <KeyValue<
> > > http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/KeyValue.html>
> > > > results)
> > > Grab the next row's worth of values.
> > >
> > >
> >
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/regionserver/InternalScanner.html
> > >
> > > Thanks,
> > > Anil Gupta
> > >
> > > On Fri, Nov 30, 2012 at 10:54 AM, anil gupta <an...@gmail.com>
> > > wrote:
> > >
> > > > Hi All,
> > > >
> > > > I am developing a Coprocessor to sort results on the basis of Cell
> > Value.
> > > > Basically an equivalent of order by clause in RDBMS.
> > > > In my subclass of BaseEndpointCoprocessor i would like to do fetch of
> > > > entire rows rather than individual KeyValue using the
> InternalScanner.
> > > But,
> > > > surprisingly there is no method to do that. Can any one tell me why
> we
> > > dont
> > > > have a method for fetching rows? What is the most optimized way to
> > fetch
> > > > rows through current InternalScanner methods?
> > > > --
> > > > Thanks & Regards,
> > > > Anil Gupta
> > > >
> > >
> > >
> > >
> > > --
> > > Thanks & Regards,
> > > Anil Gupta
> > >
> >
>
>
>
> --
> Thanks & Regards,
> Anil Gupta
>
Re: Why InternalScanner doesn't have a method that returns entire row
or object of Result
Posted by anil gupta <an...@gmail.com>.
Hi Ted,
I figured out that i have to use next from InternalScanner. Thanks for the
response.
The comment for method "Grab the next row's worth of values." was a little
confusing to me.
"Get the keyValue's for the next row" would have been better. Just
saying....
Thanks,
Anil
On Fri, Nov 30, 2012 at 5:20 PM, Ted Yu <yu...@gmail.com> wrote:
> Right.
>
> Take a look at AggregateImplementation.getAvg(), you would see how the
> following method is used.
>
> On Fri, Nov 30, 2012 at 1:53 PM, anil gupta <an...@gmail.com> wrote:
>
> > Does this method in InternalScanner gets KeyValue's for only 1 row in 1
> > call. Am i right?
> >
> > boolean *next<
> >
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/regionserver/InternalScanner.html#next%28java.util.List%29
> > >
> > *(List<
> >
> http://download.oracle.com/javase/6/docs/api/java/util/List.html?is-external=true
> > >
> > <KeyValue<
> > http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/KeyValue.html>
> > > results)
> > Grab the next row's worth of values.
> >
> >
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/regionserver/InternalScanner.html
> >
> > Thanks,
> > Anil Gupta
> >
> > On Fri, Nov 30, 2012 at 10:54 AM, anil gupta <an...@gmail.com>
> > wrote:
> >
> > > Hi All,
> > >
> > > I am developing a Coprocessor to sort results on the basis of Cell
> Value.
> > > Basically an equivalent of order by clause in RDBMS.
> > > In my subclass of BaseEndpointCoprocessor i would like to do fetch of
> > > entire rows rather than individual KeyValue using the InternalScanner.
> > But,
> > > surprisingly there is no method to do that. Can any one tell me why we
> > dont
> > > have a method for fetching rows? What is the most optimized way to
> fetch
> > > rows through current InternalScanner methods?
> > > --
> > > Thanks & Regards,
> > > Anil Gupta
> > >
> >
> >
> >
> > --
> > Thanks & Regards,
> > Anil Gupta
> >
>
--
Thanks & Regards,
Anil Gupta