Group by

• From: Eddie McGreal <emcgreal@BlackPearl.com>
• Date: Thu, 31 Oct 2002 02:42:52 -0500 (EST)
• To: "'public-qt-comments@w3.org'" <public-qt-comments@w3.org>
• Message-ID: <49FCDC8730A25C459F818F417BEC225601FEF7@bp01.blackpearl.com>

Although the spec includes a "Group by" example we have found that such an
xquery performs very poorly. The reason for this is that the number of
comparisons explode as it behaves quadratically. 
Since there is a sort by expression why not a group by as well - it would
also make mapping to SQL a little easier.
At the moment we have implemented group by as a function - with enormous
performance gains

Regards,
Eddie 

Received on Thursday, 31 October 2002 04:36:44 UTC