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Posted to derby-dev@db.apache.org by Isuru Haththotuwa <is...@gmail.com> on 2011/06/07 06:21:59 UTC

Columnar Search Support

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)

-- 
Thanks and Regards,
Isuru

Re: Columnar Search Support

Posted by "Dag H. Wanvik" <da...@oracle.com>.

Isuru Haththotuwa <is...@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