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From "Murali Krishna. P" <muralikpb...@yahoo.com>
Subject Re: Secondary indexes and transactions
Date Wed, 06 Jan 2010 16:21:06 GMT
As far as I understand transaction guarantee is there only for the operations done via api
using with TransacatonState (http://hadoop.apache.org/hbase/docs/current/api/org/apache/hadoop/hbase/client/transactional/TransactionalTable.html).
So if IndexRegion also uses a TranscationalTable for secondary index table instead of simple
HTable and uses the same TransactionState that client provides for updateIndex methods , we
can gaurantee index consistency?

Can be done via overriding Transactional api's in IndexTable and modifying IndexRegion ? 
Is there any reason for not supporting transcation gaurantee with secondary indexes, isn't
it dangerous without this? I am asking so as to decide whether we should modify this to support
it or should we implement a separate TransactionalIndexTable ?

Murali Krishna

From: Andrew Purtell <apurtell@apache.org>
To: hbase-user@hadoop.apache.org
Sent: Mon, 4 January, 2010 6:43:15 AM
Subject: Re: Secondary indexes and transactions

> > Yes.  But IIUC, the client is running a transaction that spans the update to
> > the two tables.  It'll take care of the undo should say the update to the
> > transacation table fails.
> > 
> Isn't the update to the secondary index implicitly done ? As in, does 
> the client 'see' this update ?
> My impression was that the secondary index update was done by the 
> indexedregion - and was not visible to the client : which manages occ 
> transaction ...

Yes, you are correct. I think Stack just was not precise enough in his language.

  - Andy
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