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From aaron morton <aa...@thelastpickle.com>
Subject Re: Bulk loading into live data
Date Wed, 17 Aug 2011 08:46:54 GMT
> If I SSTLoad data into that KS & CF that has the same key, it will rely on timestamps
stored in the SSTable to overwrite value "1" or not, right ?
yes. 
> What if the column is a counter ? Does it overwrite or increment ? Ie if the SST I am
loading has the exact same setup but value 2, will my value change to 3 ?
Counter columns only know how to increment (assuming no deletes), so you will get 3. See https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/io/sstable/AbstractSSTableSimpleWriter.java#L153
and https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/CounterColumn.java#L138

Cheers

-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com

On 17/08/2011, at 6:57 PM, Philippe wrote:

> http://www.datastax.com/dev/blog/bulk-loading indicates that "it is perfectly reasonable
to load data into a live, active cluster."
> 
> So lets say my cluster has a single KS & CF and it contains a key "test" with a SC
named "Cass" and a normal subcolumn named "Data" that has value 1.
> 
> If I SSTLoad data into that KS & CF that has the same key, it will rely on timestamps
stored in the SSTable to overwrite value "1" or not, right ?
> What if the column is a counter ? Does it overwrite or increment ? Ie if the SST I am
loading has the exact same setup but value 2, will my value change to 3 ?
> 
> Thanks


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