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From Dhaval Shah <prince_mithi...@yahoo.co.in>
Subject RE: Applying QualifierFilter to one column family only.
Date Fri, 20 Jul 2012 09:27:44 GMT

Alternately you can use a filter list and say first column family and qualifier filter or
second column family.. 

On Fri 20 Jul, 2012 8:40 AM IST Anoop Sam John wrote:

>Yes I was having  this doubt. So if you know exactly the qualifier names in advance you
can use this scan way.
>Else filter only u can use.
>QualifierFilter just checks the qualifier name only which CF it is part of is not checked.
>So the similar qualifier names in both T and S will get filtered out.
>You can create a simple filter of your own and plugin the same into HBase and use? Here
you can pass the CF name also and in the filterKeyValue() u can consider the CF name too.
I think it should be an easy job :)
>From: David Koch [ogdude@googlemail.com]
>Sent: Thursday, July 19, 2012 1:57 PM
>To: user@hbase.apache.org
>Subject: Re: Applying QualifierFilter to one column family only.
>Hello Anoop,
>Thank you for your answer. The QualifierFilter on T specifies a minimum
>value not one that has to be matched exactly, so merely adding a specific
>qualifier value directly to the scan does not work if I understand
>correctly :-/
>On Thu, Jul 19, 2012 at 7:05 AM, Anoop Sam John <anoopsj@huawei.com> wrote:
>> Hi David,
>>               You want the below use case in scan
>> Table :T1
>> --------------
>> CF : T           CF: S
>> q1   q2..        q1  q2 ..............
>> Now in Scan u want to scan all the qualifiers under S and one qualifier
>> under T. (I think I got ur use case correctly)
>> Well this use case u can achieve with out using any filter also.
>> Scan s = new Scan()
>> s.addFamily(S); // Tells to add all the qualifier(KVs) under this CF in
>> the result
>> s.addColumn(T,q1)
>> Use this scan object for your getScanner.
>> Using the addColumn you can add more than one qualifier under one CF too.
>> Hope this helps u.
>> -Anoop-
>> ________________________________________
>> From: David Koch [ogdude@googlemail.com]
>> Sent: Thursday, July 19, 2012 3:36 AM
>> To: user@hbase.apache.org
>> Subject: Applying QualifierFilter to one column family only.
>> Hello,
>> When scanning a table with 2 column families, is it possible to apply
>> a QualifierFilter selectively to one family but still include the other
>> family in the scan?
>> The layout of my table is as follows:
>> <rowkey>    T:<timestamp> --> <data>,    S:<summary_item>
--> <value>
>> For each <rowkey> family T contains timestamp/data key/value pairs. Column
>> S contains summary information about this row key.
>> I want to apply a QualifierFilter to column T only - i.e filter by
>> <timestamp> but return also all of S whenever the set of key/values matched
>> in T is not empty. Is this doable using standard HBase filters? If so, how?
>> If not could I implement such a filter myself using FilterBase?
>> Thank you,
>> /David

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