For anyone interested, I came across this video where Sylvain explains how counters are actually implemented in Cassandra.

http://vimeo.com/26011102


On Feb 6, 2013, at 8:08 PM, aaron morton <aaron@thelastpickle.com> wrote:

Thanks Aaron, so will there only be one "value" for each counter column per sstable just like regular columns?
Yes. 

 For some reason I was under the impression that Cassandra keeps a log of all the increments not the actual value.
Not as far as I understand. 

Cheers
 
-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand

@aaronmorton

On 6/02/2013, at 11:15 AM, Drew Kutcharian <drew@venarc.com> wrote:

Thanks Aaron, so will there only be one "value" for each counter column per sstable just like regular columns? For some reason I was under the impression that Cassandra keeps a log of all the increments not the actual value.


On Feb 5, 2013, at 12:36 PM, aaron morton <aaron@thelastpickle.com> wrote:

Are there any specific operational considerations one should make when using counter columns families?
Performance, as they incur a read and a write. 
There were some issues with overcounts in log replay (see the changes.txt). 
 
 How are counter column families stored on disk? 
Same as regular CF's. 

How do they effect compaction?
None.

Cheers

-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand

@aaronmorton

On 6/02/2013, at 7:47 AM, Drew Kutcharian <drew@venarc.com> wrote:

Hey Guys,

Are there any specific operational considerations one should make when using counter columns families? How are counter column families stored on disk? How do they effect compaction?

-- Drew