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From Cyril Auburtin <cyril.aubur...@gmail.com>
Subject Re: About Composite range queries
Date Thu, 31 May 2012 07:00:10 GMT
Thx for the answer
1 more thing, a Composite key is not hashed only once I guess?
It's hashed the number of part the composite have?
So this means there are twice or 3 or ... as many keys as for normal column
keys, is it true?
Le 31 mai 2012 02:59, "aaron morton" <aaron@thelastpickle.com> a écrit :

> Composite Columns compare each part in turn, so the values are ordered as
> you've shown them.
>
> However the rows are not ordered according to key value. They are ordered
> using the random token generated by the partitioner see
> http://wiki.apache.org/cassandra/FAQ#range_rp
>
> What is the real advantage compared to super column families?
>
> They are faster.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 29/05/2012, at 10:08 PM, Cyril Auburtin wrote:
>
> How is it done in Cassandra to be able to range query on a composite key?
>
> "key1" => (A:A:C), (A:B:C), (A:C:C), (A:D:C), (B,A,C)
>
> like get_range ("key1", start_column=(A,"), end_column=(A, C)); will
> return [ (A:B:C), (A:C:C) ] (in pycassa)
>
> I mean does the composite implementation add much overhead to make it work?
> Does it need to add other Column families, to be able to range query
> between composites simple keys (first, second and third part of the
> composite)?
>
> What is the real advantage compared to super column families?
>
> "key1" => A: (A,C), (B,C), (C,C), (D,C)  , B: (A,C)
>
> thx
>
>
>

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