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From Data Craftsman <database.crafts...@gmail.com>
Subject Re: Is this possible.
Date Thu, 26 Apr 2012 20:36:35 GMT
Data model:

REM CQL 3.0
----

$> cqlsh --cql3

drop COLUMNFAMILY user_score_v3;

CREATE COLUMNFAMILY user_score_v3
(name varchar,
 highscore float,
 x int,
 y varchar,
 z varchar,
 PRIMARY KEY (name, highscore)
);

DML is as usual, as commom, as RDBMS SQL.

Query:

Top 3,

SELECT name, highscore, x,y,z FROM user_score_v3 where name='abc'
ORDER BY highscore desc
LIMIT 3;

You may try Reversed Comparators, see
http://thelastpickle.com/2011/10/03/Reverse-Comparators/

Help this is helpful.

Thank,
Charlie | DBA


On Thu, Apr 26, 2012 at 12:34 PM, Ed Jone <edjone6@gmail.com> wrote:
> Hello,
>
> I am new to cassandra and was hoping if someone can tell me if the following
> is possible.
>
>
> Given I have a columnfamily with a list of users in each Row.
>
> Each user has the properties: name, highscore, x, y, z.
>
> I want to use name as the column key, but I want the columns to be sorted by
> highscore (always).
>
> The only reads would be to get the top N users by highscore in a given row.
> I thought about adding the weight to the name as the key (eg:
> 299.76-johnsmith) but then I would not be able to update a given user.
>
> This was not possible in the past, but I am not familiar, with the newer
> cassandra versions.


--
Thanks,

Charlie (@mujiang) 一个 木匠
=======
Data Architect Developer
http://mujiang.blogspot.com

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