May I point to complex event processing, see http://esper.codehaus.org. Esper
provides a SQL-like language for performing the queries, the engine internally
maintains the indexes for answering queries fast. EsperHA runs on Cassandra.
Best regards,
Tom
project lead Esper
________________________________
From: David McNelis <dmcne...@agentisenergy.com>
To: user@cassandra.apache.org
Sent: Fri, March 25, 2011 7:54:41 AM
Subject: Re: data aggregation in Cassandra
That kind of aggregation is certainly possible today, programmatically... but
if
you want to do it in cassandra only, you are out of luck, today. But it
sounds
like the project DataStax just announced might help quite a bit with a use case
like that.
David
Sent from my Droid
On Mar 25, 2011 3:58 AM, "Saurabh Sehgal" <saurabh....@gmail.com> wrote:
> Hi All,
>
> I am evaluating Cassandra as a data store for my application.
>
> This is what the format of the data I want to store looks like:
>
> {
> timestampuuid: unique time stamp
> finite_set_of_values_attribute1: this is a value from a finite set ,
> lets say {a,b,c,d}
> finite_set_of_values_attribute2: this is a value from a finite set, lets
> say {e,f,g}
> randomAttribute: xyz
> randomAttribute: 123
> }
>
> How can I efficiently model this data to answer questions like:
>
> 1. From timestampuuid1 to timestampuuid2 I want all values
> with finite_set_of_values_attribute1 = "a",
> and finite_set_of_values_attribute2 = "e"
> 2. I want all values from timestamp1 to timestamp2 sorted by
> finite_set_of_values_attribute1
>
> Is it possible to do such data aggregations efficiently ? I sense a
> map-reduce approach might work better for this. Is there something similar
> to aggregate data in such a way in Cassandra ?
>
> Thank you,
>
> Saurabh
