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HBase, mail # user - Question


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Dalia Sobhy 2012-11-10, 22:11
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Ted Yu 2012-11-10, 22:25
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Dalia Sobhy 2012-11-11, 16:07
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Ted Yu 2012-11-11, 16:24
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Dalia Sobhy 2012-11-11, 19:42
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Re: Question
yuzhihong@... 2012-11-11, 20:31
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
>>>>>
>>>
>>>
>                        
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Dalia Sobhy 2012-11-13, 22:14
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Ted Yu 2012-11-13, 22:29
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Dalia Sobhy 2012-11-14, 09:09
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Dalia Sobhy 2012-11-15, 00:07
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Ted Yu 2012-11-15, 00:22