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From Tyler Hobbs <ty...@datastax.com>
Subject Re: Cassandra 3.1 - Aggregation query failure
Date Fri, 18 Dec 2015 16:26:55 GMT
On Fri, Dec 18, 2015 at 9:17 AM, DuyHai Doan <doanduyhai@gmail.com> wrote:

> Cassandra will perform a full table scan and fetch all the data in memory
> to apply the aggregate function.


Just to clarify for others on the list: when executing aggregation
functions, Cassandra *will* use paging internally, so at most one page
worth of data will be held in memory at a time.  However, if your
aggregation function retains a large amount of data, this may contribute to
heap pressure.


-- 
Tyler Hobbs
DataStax <http://datastax.com/>

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