SQL challenge
From: Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be>
Date: Mon, 12 Jul 2004 23:09:51 GMT
Message-Id: <pan.2004.07.12.23.10.13.427982_at_REMOVETHIS.pandora.be>
At the last SIGMOD conference I heard an anecdote about how Jim Gray had gained the respect of some of his colleagues by computing the convex hull of a set of three-dimensional points in a table with a single SQL query that used only basic SQL (SQL-89). To be a little more concrete, the input is a relation P(x,y,z) and the output L(x1,y1,z1,x2,y2,z2) that describes the minimal set of edges that span the convex hull of the nodes in P.
Date: Mon, 12 Jul 2004 23:09:51 GMT
Message-Id: <pan.2004.07.12.23.10.13.427982_at_REMOVETHIS.pandora.be>
At the last SIGMOD conference I heard an anecdote about how Jim Gray had gained the respect of some of his colleagues by computing the convex hull of a set of three-dimensional points in a table with a single SQL query that used only basic SQL (SQL-89). To be a little more concrete, the input is a relation P(x,y,z) and the output L(x1,y1,z1,x2,y2,z2) that describes the minimal set of edges that span the convex hull of the nodes in P.
Who of the SQL gurus here is as smart as Jim Gray. :-)
- Jan Hidders