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 >>> > >>>>> >>> > >>> >>> > >>> >>> > > >
