On Apr 21, 2011, at 3:19 AM, Mridul Muralidharan wrote:

> 
> In general (on hadoop based systems), if the input is not immutable - you can 
> end up with issues during task re-execution, etc.
> This happens not just for cassandra but for hbase, others too - where you 
> modify data in-place.
> 

So do you mean that between the time of the first execution and the time of the 
re-execution, input data can change?  Yes that's possible.  However, unless you 
are reading stale data the second time, it's not a consistency issue, is it?  I 
mean, if I am guaranteed to read the most recent data on the first execution 
and the second execution, that's consistent.  If I am reading updated data the 
second time, that's consistent and may or may not be a problem.

Just trying to make sure I understand.

> 
> 
> Regards,
> Mridul
> 
> On Thursday 21 April 2011 04:29 AM, Bing Wei wrote:
>> Hi, All.
>> 
>> When I do a pig query on Cassandra, and the Cassandra is updated by
>> application at the same time, what will happen? I may get inconsistent
>> results, right?
>> 
> 

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