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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: repeated timeouts on quorum reads
Date Thu, 22 Oct 2009 22:34:39 GMT
Okay, so the fundamental problem is that deserializing a supercolumn
with 30k subcolumns is really really slow. (Like we say on
http://wiki.apache.org/cassandra/CassandraLimitations, "avoid a data
model that requires large numbers of subcolumns.")

But we were also being needlessly inefficient after deserialization;
I've attached a patch (against trunk) to
https://issues.apache.org/jira/browse/CASSANDRA-510.  This gives a
30-50% improvement in my tests.

You're looking for more like an order of magnitude improvement though,
so I would say splitting each supercolumn off into its own row is
probably the way to go.

-Jonathan

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