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https://issues.apache.org/jira/browse/CASSANDRA-4914?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13852757#comment-13852757
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Sylvain Lebresne commented on CASSANDRA-4914:
---------------------------------------------
bq. Basically, enhance the metadata so users can declare which aggregations
they want on a table, and along which dimensions. Then, maintain those
aggregations in separate CFs as part of the flush/compaction processes (and
extend CQL to allow them to be queried).
Other opinions may vary, but as for my own, I think this may be going a bit too
far for what should be in C*/CQL. This feels to lend a bit outside of what we
can reasonably provide out of the box, and in particular I suspect doing this
in a way that is generic enough is not a small amount of work. Providing
slightly more convenient building blocks like CASSANDRA-6412 but letting users
do what they want with it feels a tad more on-focus to me.
But "interest" is not a black and white concept. If someone comes up with a
precise plan for something like this that is elegant, generic enough and don't
require a zillions of un-maintainable lines of codes, it'll certainly boost my
interest meter.
> Aggregate functions in CQL
> --------------------------
>
> Key: CASSANDRA-4914
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4914
> Project: Cassandra
> Issue Type: New Feature
> Reporter: Vijay
> Assignee: Vijay
> Fix For: 2.1
>
>
> The requirement is to do aggregation of data in Cassandra (Wide row of column
> values of int, double, float etc).
> With some basic agree gate functions like AVG, SUM, Mean, Min, Max, etc (for
> the columns within a row).
> Example:
> SELECT * FROM emp WHERE empID IN (130) ORDER BY deptID DESC;
>
> empid | deptid | first_name | last_name | salary
> -------+--------+------------+-----------+--------
> 130 | 3 | joe | doe | 10.1
> 130 | 2 | joe | doe | 100
> 130 | 1 | joe | doe | 1e+03
>
> SELECT sum(salary), empid FROM emp WHERE empID IN (130);
>
> sum(salary) | empid
> -------------+--------
> 1110.1 | 130
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