# Re: Nested Sets vs. Nested Intervals

Date: Thu, 10 Nov 2005 17:25:31 -0500

Message-ID: <NomdnXwlJoREVe7eRVn-sA_at_comcast.com>

<amado.alves_at_netcabo.pt> wrote in message
news:1131660473.524073.265700_at_g43g2000cwa.googlegroups.com...

> "Do you mean to say that the entity is presented as a graph whose nodes

*>
**> are values of some type and edges are directed paths with two paths (S
**> and T) per each node?"
**>
**> No. A node is either a datum or a pivot. An edge is directed. S, T
**> means the sources, targets of a node, if any. A node may have any
**> number of M sources, any number N of targets, as long as M + N > 0.
*

So how would you represent , say, three entities like 'employee', 'department', 'company' ?

*>
*

> For a connection from x to y we say x is a source of y, y is a target

*> of x.
**>
**> S, T are also called A+, A- in the literature (A from "Adjacent").
**>
**>
*

Received on Thu Nov 10 2005 - 23:25:31 CET