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From David Boxenhorn <da...@taotown.com>
Subject Re: Indexes on heterogeneous rows
Date Sun, 17 Apr 2011 09:23:32 GMT
Thanks, Jonathan. I think I understand now.

To sum up: Everything would work, but if your only equality is on "type"
(all the rest inequalities), it could be very inefficient.

Is that right?

On Thu, Apr 14, 2011 at 7:22 PM, Jonathan Ellis <jbellis@gmail.com> wrote:

> On Thu, Apr 14, 2011 at 6:48 AM, David Boxenhorn <david@taotown.com>
> wrote:
> > The reason why I put "type" first is that queries on type will
> > always be an exact match, whereas the other clauses might be
> inequalities.
>
> Expression order doesn't matter, but as you imply, non-equalities
> can't be used in an index lookup and have to be checked in a nested
> loop phase afterwards.
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of DataStax, the source for professional Cassandra support
> http://www.datastax.com
>

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