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Posted to user@cassandra.apache.org by Stephen Pope <St...@quest.com> on 2011/07/28 21:08:18 UTC

Aggregation and Co-Processors

I just finished watching the video by Eric Evans on "CQL - Not just NoSQL. It's MoSQL", and I heard mention of aggregation queries. He said there's been some talk about it, and that you guys were calling it "co-processors". Can somebody give me the gist of what that's all about? I couldn't find any mention of it on the wiki.

Cheers,
Steve

Re: Can I slice on composite indexes?

Posted by aaron morton <aa...@thelastpickle.com>.

You can slice the "key1" row to get the columns that have "xyz" as the value for the first component in the column name.  Check the docs in your client for how to do that. 

Hope that helps. 

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

On 21/12/2011, at 3:04 PM, Maxim Potekhin wrote:

> Let's say I have rows with composite columns Like
> 
> ("key1", {('xyz', 'abc'): 'colval1'},  {('xyz', 'def'): 'colval2'})
> ("key2", {('ble', 'meh'): 'otherval'})
> 
> Is it possible to create a composite type index such that I can query on 'xyz'
> and get the first two columns?
> 
> Thanks
> 
> Maxim
>

Can I slice on composite indexes?

Posted by Maxim Potekhin <po...@bnl.gov>.

Let's say I have rows with composite columns Like

("key1", {('xyz', 'abc'): 'colval1'},  {('xyz', 'def'): 'colval2'})
("key2", {('ble', 'meh'): 'otherval'})

Is it possible to create a composite type index such that I can query on 
'xyz'
and get the first two columns?

Thanks

Maxim

Re: Aggregation and Co-Processors

Posted by Ryan King <ry...@twitter.com>.

On Thu, Jul 28, 2011 at 12:08 PM, Stephen Pope <St...@quest.com> wrote:
> I just finished watching the video by Eric Evans on “CQL – Not just NoSQL.
> It’s MoSQL”, and I heard mention of aggregation queries. He said there’s
> been some talk about it, and that you guys were calling it “co-processors”.
> Can somebody give me the gist of what that’s all about? I couldn’t find any
> mention of it on the wiki.

There's no mention on the wiki because they don't exist. There are
some ideas in jira though:

https://issues.apache.org/jira/browse/CASSANDRA-1311
https://issues.apache.org/jira/browse/CASSANDRA-1016

-ryan