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From Anoop Sam John <anoo...@huawei.com>
Subject RE: Applying QualifierFilter to one column family only.
Date Fri, 20 Jul 2012 03:10:00 GMT
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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