Take a look at src/main/java/org/apache/hadoop/hbase/client/coprocessor/LongColumnInterpreter.java for an example ?
Since ColumnInterpreter involves dealing with Java generics, I feel you can try hive which doesn't require coding in Java - at least initially. Cheers On Wed, Nov 14, 2012 at 4:07 PM, Dalia Sobhy <[email protected]>wrote: > > I cannot understand you TEd ? > > Can you please tell me how to initialize the ColumnInterpreter instance? > > I am using String for diagnosis qualifier. > > Which is better in aggregate functions : hbase OR hive? > > Thanks in advance, > > > Subject: Re: Question > > From: [email protected] > > Date: Wed, 14 Nov 2012 11:09:26 +0200 > > To: [email protected] > > > > String > > > > Sent from my iPhone > > > > On 2012-11-14, at 12:30 AM, "Ted Yu" <[email protected]> wrote: > > > > > What number format did you use for the cardiac column family ? > > > I assume you store double as byte array. > > > > > > Cheers > > > > > > On Tue, Nov 13, 2012 at 2:14 PM, Dalia Sobhy < > [email protected]>wrote: > > > > > >> Hello Ted: > > >> > > >> I have a patient table which contains two column families: info and > > >> cardiac. > > >> > > >> I need to count the number of people who suffer from a particular > > >> diagnosis within cardiac. > > >> > > >> For instance the number of patients suffering from "heart failure" > > >> > > >> Sent from my iPad > > >> > > >> On Nov 13, 2012, at 11:00 PM, "Ted Yu" <[email protected]> wrote: > > >> > > >>> Currently http://hbase.apache.org/book.html gives me networks error. > > >>> You should be able to find example of how Java client connects to > HBase > > >> cluster. > > >>> > > >>> How ColumnInterpreter is initialized depends on your schema. Can you > > >> tell us more about your schema ? > > >>> > > >>> Thanks > > >>> > > >>> On Tue, Nov 13, 2012 at 12:40 PM, Dalia Sobhy < > > >> [email protected]> wrote: > > >>>> > > >>>> > > >>>> > > >>>> > > >>>> Begin forwarded message: > > >>>> > > >>>>> From: Dalia Sobhy <[email protected]> > > >>>>> Date: November 12, 2012, 10:12:57 PM GMT+02:00 > > >>>>> To: <[email protected]> > > >>>>> Subject: RE: Question > > >>>>> > > >>>>> Thanks, > > >>>>> > > >>>>> But how to initialize the ColumnInterpreter, I mean how to link it > > >> with a table. > > >>>>> > > >>>>> Another aspect, its my first time to use java classes for hbase, I > was > > >> using thrift server to connect to hbase. But due to the need for > aggregate > > >> functions i shifted to hbase 0.92. > > >>>>> > > >>>>> So could you explain to me in brief how are the java classes > connected > > >> to hbase server. > > >>>>> > > >>>>> Thanks in advance :D > > >>>>> > > >>>>> Date: Mon, 12 Nov 2012 11:35:58 -0800 > > >>>>> > > >>>>> Subject: Re: Question > > >>>>> From: [email protected] > > >>>>> To: [email protected] > > >>>>> CC: [email protected] > > >>>>> > > >>>>> > > >>>>> double is primitive type. > > >>>>> Replace with Double. > > >>>>> > > >>>>> Cheers > > >>>>> > > >>>>> On Mon, Nov 12, 2012 at 11:31 AM, Dalia Sobhy < > > >> [email protected]> wrote: > > >>>>> > > >>>>> > > >>>>> Syntax error on token "double", Dimensions expected after this > token > > >>>>> > > >>>>> Pastebin link: > > >>>>> http://pastebin.com/dcvaMvLw > > >>>>> > > >>>>> I am trying to send it on the group but I dunno why hotmail > disagrees > > >> and sends me postmaster failure so weird!!! > > >>>>> > > >>>>> > > >>>>>> CC: [email protected] > > >>>>>> From: [email protected] > > >>>>>> Subject: Re: Question > > >>>>>> Date: Sun, 11 Nov 2012 12:31:16 -0800 > > >>>>>> To: [email protected] > > >>>>> > > >>>>>> > > >>>>>> What error did you get ? > > >>>>>> Please use pastebin to share. > > >>>>>> > > >>>>>> Thanks > > >>>>>> > > >>>>>> > > >>>>>> > > >>>>>> On Nov 11, 2012, at 11:42 AM, Dalia Sobhy < > > >> [email protected]> wrote: > > >>>>>> > > >>>>>>> > > >>>>>>> Hi Ted, > > >>>>>>> > > >>>>>>> I am using hbase 0.92.1 > > >>>>>>> > > >>>>>>> When I tried the following code I got errors: > > >>>>>>> > > >>>>>>> AggregateProtocol agg; > > >>>>>>> long rowcount = agg.getRowNum(ColumnInterpreter<string, int>, > > >> scan); > > >>>>>>> > > >>>>>>> double sum = aggregationClient.avg(TABLE_NAME, ci, scan); > > >>>>>>> > > >>>>>>> even though I tried it with String (s in capital) same errors, do > > >> u know why? > > >>>>>>> > > >>>>>>>> Date: Sun, 11 Nov 2012 08:24:29 -0800 > > >>>>>>>> Subject: Re: Question > > >>>>>>>> From: [email protected] > > >>>>>>>> To: [email protected] > > >>>>>>>> > > >>>>>>>> Dalia: > > >>>>>>>> If you look at: > > >>>>>>>> public interface ColumnInterpreter<T, S> { > > >>>>>>>> > > >>>>>>>> you would see: > > >>>>>>>> * @param <T> Cell value data type > > >>>>>>>> * @param <S> Promoted data type > > >>>>>>>> > > >>>>>>>> S can represent sum of values of T. The rationale was that > > >> aggregation of > > >>>>>>>> one type (integer, e.g.) may have to be represented by another > > >> type > > >>>>>>>> (double, e.g.) > > >>>>>>>> > > >>>>>>>> From this blog you can get some history on this subject: > > >> > http://zhihongyu.blogspot.com/2011/03/genericizing-endpointcoprocessor.html > > >>>>>>>> > > >>>>>>>> For row counting, it is already implemented: > > >>>>>>>> public <T, S> long getRowNum(ColumnInterpreter<T, S> ci, Scan > > >> scan) > > >>>>>>>> You can embed your filter in scan object. > > >>>>>>>> > > >>>>>>>> Cheers > > >>>>>>>> > > >>>>>>>> On Sun, Nov 11, 2012 at 8:07 AM, Dalia Sobhy < > > >> [email protected]>wrote: > > >>>>>>>> > > >>>>>>>>> > > >>>>>>>>> > > >>>>>>>>> Thanks Ted :D > > >>>>>>>>> > > >>>>>>>>> But can anyone explain to me this sentence: > > >>>>>>>>> > > >>>>>>>>> ColumnInterpreter<T, S> ci > > >>>>>>>>> > > >>>>>>>>> How to set a ColumnInterpreter ?? What is T and Whats S? > > >>>>>>>>> > > >>>>>>>>> I want to perform average on an Aggregationclient, so could > > >> anyone provide > > >>>>>>>>> me with a sample code? > > >>>>>>>>> > > >>>>>>>>> Also if i want to count the number of rows which has a specific > > >> value ? > > >>>>>>>>> What to use Filters or AggregationClient? > > >>>>>>>>> > > >>>>>>>>> Thanks in advance, > > >>>>>>>>> > > >>>>>>>>>> Date: Sat, 10 Nov 2012 14:25:22 -0800 > > >>>>>>>>>> Subject: Re: Question > > >>>>>>>>>> From: [email protected] > > >>>>>>>>>> To: [email protected] > > >>>>>>>>>> > > >>>>>>>>>> Take a look at AggregationClient.java and > > >> TestAggregateProtocol.java > > >>>>>>>>>> > > >>>>>>>>>> Cheers > > >>>>>>>>>> > > >>>>>>>>>> On Sat, Nov 10, 2012 at 2:11 PM, Dalia Sobhy < > > >> [email protected] > > >>>>>>>>>> wrote: > > >>>>>>>>>> > > >>>>>>>>>>> > > >>>>>>>>>>> Dear all, > > >>>>>>>>>>> > > >>>>>>>>>>> I want to use the aggregate functions, but do anyone have a > > >> code or > > >>>>>>>>> sth to > > >>>>>>>>>>> understand them .. > > >>>>>>>>>>> > > >>>>>>>>>>> Thanks > > >>>>>>>>>>> > > >>>>>>>>>>> Best Regards > > >>>>>>>>>>> Dalia > > >> > >
