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From dag.wan...@oracle.com (Dag H. Wanvik)
Subject Re: Columnar Search Support
Date Tue, 07 Jun 2011 12:08:02 GMT
Isuru Haththotuwa <isurulucky@gmail.com> writes:

> Hi,
>
> Does Derby support the Columnar method for querying? If not, is this a
> possible thing to implement in Derby, to compare the performance with regard
> to row oriented approach? (For some queries only, as an example when
> an aggregate
> needs to be computed over many rows but only for a smaller subset of all
> columns of data)

You could "simulate" it by having covering indexes for the rows you are
interested, at the cost of storing extra index B-trees.

Dag

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