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Home -> Community -> Usenet -> comp.databases.theory -> Re: Nested Sets vs. Nested Intervals
"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.
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").
The "traditional" network model being Codasyl, nodes are tables, and edges have a predefined semantic value, member I think, I don't have the reference at hand, anyway very different (and anyway I'm even less interested in Codasyl than in RDF). Received on Thu Nov 10 2005 - 16:07:53 CST
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