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From aaron morton <aa...@thelastpickle.com>
Subject Re: need some help with counters
Date Fri, 10 Jun 2011 02:04:10 GMT
I may be missing something but could you use a column for each of the last 48 hours all in
the same row for a url ?

e.g. 
{
	"/url.com/hourly" : {
		"20110609T01:00:00" : 456,
		"20110609T02:00:00" : 4567,
	}
}

Increment the current hour only. Delete the older columns either when a read detects there
are old values or as a maintenance job. Or as part of writing values for the first 5 minutes
of any hour. 
 
The row will get spread out over a lot of sstables which may reduce read speed. If this is
a problem consider a separate CF with more aggressive GC and compaction settings. 
 
Cheers


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

On 10 Jun 2011, at 09:28, Ian Holsman wrote:

> So would doing something like storing it in reverse (so I know what to delete) work?
Or is storing a million columns in a supercolumn impossible. 
> 
> I could always use a logfile and run the archiver off that as a worst case I guess. 
> Would doing so many deletes screw up the db/cause other problems?
> 
> ---
> Ian Holsman - 703 879-3128
> 
> I saw the angel in the marble and carved until I set him free -- Michelangelo
> 
> On 09/06/2011, at 4:22 PM, Ryan King <ryan@twitter.com> wrote:
> 
>> On Thu, Jun 9, 2011 at 1:06 PM, Ian Holsman <hadoop@holsman.net> wrote:
>>> Hi Ryan.
>>> you wouldn't have your version of cassandra up on github would you??
>> 
>> No, and the patch isn't in our version yet either. We're still working on it.
>> 
>> -ryan


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