Re: Nested Sets vs. Nested Intervals

Each single concept is represented by a vertex. The properties of the concept are represented by topologies involving the vertex. The fact that employee x10 works in the accounting department may be modelled as

Employees => x10
x10 => x11
WorksIn => x11
x11 => Accounting

where x => y means connected from x to y. Note that this model makes similarly possible and simple to query for where does x10 work

T (T (x10) ^ T (WorksIn))

and for all workers in accounting

T (Employees) ^ S [S (Accounting) ^ T (WorksIn)]

(A more demanding schema would require a department be also a pivot, so it could have attributes attached, and be a member of a Departments like employee x10 is a member of Employees.) Received on Thu Nov 10 2005 - 18:07:56 CST