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https://issues.apache.org/jira/browse/CASSANDRA-6644?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13887658#comment-13887658
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Sylvain Lebresne commented on CASSANDRA-6644:
---------------------------------------------
We do plan on supporting a somewhat general nothing of row filtering functions
at some point: CASSANDRA-4914. It's obviously not done yet, and at this point
it's relatively clear it won't make it in 2.1, but I do intent on tackling it
for 3.0 if no-ones beats me to it so it will happen.
And because I do think a general server-side filtering/aggregation mechanism is
the way to go and I do intend to get that in, I don't think it's a good idea to
add new syntax for very specific case like this one. Especially since I'm not
all that convinced that this particular one is all that generally useful (not
saying it's useless, just not sure it's a very common need).
> CQL: Select every nth row within the same partition key
> -------------------------------------------------------
>
> Key: CASSANDRA-6644
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6644
> Project: Cassandra
> Issue Type: Wish
> Reporter: Jorge Bay
>
> In a time-series schema (like metrics), it is common to create
> roollups/buckets with datapoints at different rate.
> It would be nice to have a keyword in CQL to be able to retrieve one every
> nth row (within a single storage engine wide row).
> For example, in the following schema:
> CREATE TABLE metrics (
> ... metric_id varchar,
> ... ts timestamp,
> ... value float,
> ... PRIMARY KEY (metric_id, ts)
> ... );
> The following query, will retrieve 1 in every 3 rows:
> -- SKIP keyword or something like that
> SELECT ts, value WHERE metric_id = ? SKIP 2;
> This would be very useful for continuous (and somehow linear) metrics.
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