Hi Mohit,

the best way to study this is to look at MultiVersionConsistencyControl.java 
(since you are asking how this handled internally).

In a nutshell this ensures that read operations don't see writes that are not 
completed, by (1) defining a thread read point that is rolled forward only 
after a completed operations and (2) assigning a special timestamp (not the 
timestamp that you set from the client API) to all KeyValues.

-- Lars


----- Original Message -----
From: Mohit Anchlia <[email protected]>
To: [email protected]
Cc: 
Sent: Thursday, December 1, 2011 2:22 PM
Subject: Atomicity questions

I have some questions about ACID after reading this page,
http://hbase.apache.org/acid-semantics.html

- Atomicity point 5 : row must either be "a=1,b=1,c=1" or
"a=2,b=2,c=2" and must not be something like "a=1,b=2,c=1".

How is this internally handled in hbase such that above is possible?

Reply via email to