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From samal <samalgo...@gmail.com>
Subject Re: RE Ordering counters in Cassandra
Date Tue, 22 May 2012 12:25:30 GMT
Secondary index is not supported for counters plus you must know column
name to support secondary index on regular column.
On 22-May-2012 5:34 PM, "Filippo Diotalevi" <filippo@ntoklo.com> wrote:

>  Thanks for all the answers, they definitely helped.
>
> Just out of curiosity, is there any underlying architectural reason why
> it's not possible to order a row based on its counters values? or is it
> something that might be in the roadmap in the future?
>
> --
> Filippo Diotalevi
>
> On Tuesday, 22 May 2012 at 08:48, Romain HARDOUIN wrote:
>
>
> I mean iterate over each column -- more precisly: *bunches of columns*
> using slices -- and write new columns in the inversed index.
> Tamar's data model is made for real time analysis. It's maybe overdesigned
> for a daily ranking.
> I agree with Samal, you should split your data across the space of tokens.
> Only CF Ranking feeding would be affected, not the "top N" queries.
>
> Filippo Diotalevi <filippo@ntoklo.com> a écrit sur 21/05/2012 19:05:28 :
>
> > Hi Romain,
> > thanks for your suggestion.
> >
> > When you say " build every day a ranking in a dedicated CF by
> > iterating over events:" do you mean
> > - load all the columns for the specified row key
> > - iterate over each column, and write a new column in the inversed index
> > ?
> >
> > That's my current approach, but since I have many of these wide rows
> > (1 per day), the process is extremely slow as it involves moving an
> > entire row from Cassandra to client, inverting every column, and
> > sending the data back to create the inversed index.
>
>
>

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