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From Weiping Qu ...@informatik.uni-kl.de>
Subject Questions regarding HBase consistency
Date Tue, 26 May 2015 22:04:00 GMT
Dear HBase Community,

As far as I know, HBase supports strong consistency at row level, 
strictly to say, at region level I think, since one MVCC instance is 
used in each HRegion instance to schedule writes and reads.
Read committed is the default transaction isolation level.
I am wondering whether serializable snapshot isolation at table level is 
possible like Postgresql or other MVCC-based databases.
However, as a scan might span across multiple regions in HBase, it is 
likely that the scan results would have phantom reads on certain regions.
So my questions is that, why strong consistency at region level instead 
of table level?
Is that really not needed? or due to scalability or high availability? 
or not easy to implement?


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