Re: Aggregates: Largest Groups
From: Gene Wirchenko <genew_at_ocis.net>
Date: Mon, 22 Mar 2010 13:53:06 -0700
Message-ID: <iulfq51qtfcff5apq072uv1leso4m40ash_at_4ax.com>
Date: Mon, 22 Mar 2010 13:53:06 -0700
Message-ID: <iulfq51qtfcff5apq072uv1leso4m40ash_at_4ax.com>
On Mon, 22 Mar 2010 15:42:09 -0500, david_at_fetter.org (David Fetter) wrote:
>Let's say I have a traffic monitoring system. The stream of data
>coming in records a timestamp and a speed for each vehicle.
>
>I'd like to know what all the groups of vehicles larger than X whose
>with average speed over Y is.
>
>Any ideas how to approach this?
First, define your terms. What is a group? What does "larger than X" mean? (Size of vehicle? Number of vehicles in the group?)
Sincerely,
Gene Wirchenko Received on Mon Mar 22 2010 - 21:53:06 CET