Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Plain View
HBase, mail # user - Applying QualifierFilter to one column family only.


+
David Koch 2012-07-18, 22:06
+
Anoop Sam John 2012-07-19, 05:05
+
David Koch 2012-07-19, 08:27
+
Anoop Sam John 2012-07-20, 03:10
Copy link to this message
-
Re: Applying QualifierFilter to one column family only.
Anoop Sam John 2012-07-20, 03:12
>Yes I was having  this doubt.
Yes I was having this doubt abt ur use case. I assumed ur use case is like u know the qualifier names in advance. :)
____________________________________
From: Anoop Sam John
Sent: Friday, July 20, 2012 8:40 AM
To: [EMAIL PROTECTED]
Subject: RE: Applying QualifierFilter to one column family only.

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 :)

-Anoop-
_________________________________
From: David Koch [[EMAIL PROTECTED]]
Sent: Thursday, July 19, 2012 1:57 PM
To: [EMAIL PROTECTED]
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 :-/

/David
On Thu, Jul 19, 2012 at 7:05 AM, Anoop Sam John <[EMAIL PROTECTED]> 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 [[EMAIL PROTECTED]]
> Sent: Thursday, July 19, 2012 3:36 AM
> To: [EMAIL PROTECTED]
> 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
>
+
Dhaval Shah 2012-07-20, 09:27