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HBase >> mail # user >> Re: Best technique for doing lookup with Secondary Index


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anil gupta 2012-10-26, 15:14
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anil gupta 2012-10-26, 16:43
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fding hbase 2012-10-26, 10:14
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Jerry Lam 2012-10-26, 14:29
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Ramkrishna.S.Vasudevan 2012-10-26, 14:33
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anil gupta 2012-10-26, 06:46
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Ramkrishna.S.Vasudevan 2012-10-26, 08:13
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anil gupta 2012-10-24, 21:40
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Anoop Sam John 2012-10-25, 04:44
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RE: Best technique for doing lookup with Secondary Index
Just out of curiosity,
> The secondary index is stored in table "B" as rowkey B -->
> family:<rowkey
> A>  
what is rowkey B here?
> 1. Scan the secondary table by using prefix filter and startRow.
How is the startRow determined for every query ?

Regards
Ram

> -----Original Message-----
> From: Anoop Sam John [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, October 25, 2012 10:15 AM
> To: [EMAIL PROTECTED]
> Subject: RE: Best technique for doing lookup with Secondary Index
>
> >I build the secondary table "B" using a prePut RegionObserver.
>
> Anil,
>        In prePut hook u call HTable#put()?  Why use the network calls
> from server side here then? can not handle it from client alone? You
> can have a look at Lily project.   Thoughts after seeing ur idea on put
> and scan..
>
> -Anoop-
> ________________________________________
> From: anil gupta [[EMAIL PROTECTED]]
> Sent: Thursday, October 25, 2012 3:10 AM
> To: [EMAIL PROTECTED]
> Subject: Best technique for doing lookup with Secondary Index
>
> Hi All,
>
> I am using HBase 0.92.1. I have created a secondary index on table "A".
> Table A stores immutable data. I build the secondary table "B" using a
> prePut RegionObserver.
>
> The secondary index is stored in table "B" as rowkey B -->
> family:<rowkey
> A>  . "<rowkey A>" is the column qualifier. Every row in B will only on
> have one column and the name of that column is the rowkey of A. So the
> value is blank. As per my understanding, accessing column qualifier is
> faster than accessing value. Please correct me if i am wrong.
>
>
> HBase Querying approach:
> 1. Scan the secondary table by using prefix filter and startRow.
> 2. Do a batch get on primary table by using HTable.get(List<Get>)
> method.
>
> The above approach for retrieval works fine but i was wondering it
> there is
> a better approach. I was planning to try out doing the retrieval using
> coprocessors.
> Have anyone tried using coprocessors? I would appreciate if others can
> share their experience with secondary index for HBase queries.
>
> --
> Thanks & Regards,
> Anil Gupta
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anil gupta 2012-10-25, 22:10
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Ramkrishna.S.Vasudevan 2012-10-26, 04:20
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Anoop Sam John 2012-10-26, 04:33
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Anoop Sam John 2012-10-26, 04:06
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anil gupta 2012-10-26, 04:44
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Doug Meil 2012-10-27, 00:35
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB