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From DuyHai Doan <doanduy...@gmail.com>
Subject Re: Multi-column range scans
Date Mon, 14 Jul 2014 07:45:25 GMT
Hello Mathew

 Since Cassandra 2.0.6 it is possible to query over composites:
https://issues.apache.org/jira/browse/CASSANDRA-4851

For your example:

select * from skill_count where skill='Complaints' and
(interval_id,skill_level) >= (1402359300000,5) and interval_id <
1402359900000;


On Mon, Jul 14, 2014 at 6:09 AM, Matthew Allen <matthew.j.allen@gmail.com>
wrote:

> Hi,
>
> We have a roll-up table that as follows.
>
> CREATE TABLE SKILL_COUNT (
>   skill text,
>   interval_id bigint,
>   skill_level int,
>   skill_count int,
>   PRIMARY KEY (skill, interval_id, skill_level));
>
> Essentially,
>   skill = a names skill i.e. "Complaints"
>   interval_id = a rounded epoch time (15 minute intervals)
>   skill_level = a number/rating from 1-10
>   skill_count = the number of people with the specified skill, with the
> specified skill level, logged in at the interval_id
>
> We'd like to run the following query against it
>
> select * from skill_count where skill='Complaints' and interval_id >=
> 1402359300000 and interval_id < 1402359900000 and skill_level >= 5;
>
> to get a count of people with the relevant skill and level at the
> appropriate time.  However I am getting the following message.
>
> Bad Request: PRIMARY KEY part skill_level cannot be restricted (preceding
> part interval_id is either not restricted or by a non-EQ relation)
>
> Looking at how the data is stored ...
>
> -------------------
> RowKey: Complaints
> => (name=1402359300000:2:, value=, timestamp=1405308260403000)
> => (name=1402359300000:2:skill_count, value=0000000a,
> timestamp=1405308260403000)
> => (name=1402359300000:5:, value=, timestamp=1405308260403001)
> => (name=1402359300000:5:skill_count, value=00000014,
> timestamp=1405308260403001)
> => (name=1402359300000:8:, value=, timestamp=1405308260419000)
> => (name=1402359300000:8:skill_count, value=0000001e,
> timestamp=1405308260419000)
> => (name=1402359300000:10:, value=, timestamp=1405308260419001)
> => (name=1402359300000:10:skill_count, value=00000001,
> timestamp=1405308260419001)
>
> Should cassandra be able to allow for an extra level of filtering ? or is
> this something that should be performed from within the application.
>
> We have a solution working in Oracle, but would like to store this data in
> Cassandra, as all the other data that this solution relies on already sits
> within Cassandra.
>
> Appreciate any guidance on this matter.
>
> Matt
>

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