Re: The original version

(i)
When we talk about modeling relationships in Anchor Modeling, then the following question arises: what do the authors of Anchor Modeling model?
If we have a relationship between two entities, then we should notice that both entities change over time. Each entity can have for instance 10 attributes and each attribute changes independent of time. Also, the relationship itself can change with time. In my paper I do not model relationships between entities, but relationships between the corresponding states of two entities (or relationships). In their basic version from 2009 Anchor Modeling defines relationships in the following way:

Def 9 (Historized Tie). A historized tie Htie(C1,…,Cn, T) relating a set of
anchors {A1(C1),…,Am(Cm)} is a table with n + 1 columns satisfying n
>= m

and n >= 2, where for every i in [1, n], Htie.Ci is a non-null foreign key to some
Aj.Cj for j in [1,m], and the domain of the last column T is a non- null time
type. The primary key for Htie is a subset of (C1,…,Cn, T) containing T.

(ii)
According to Leibniz’s Law, every entity becomes another entity when its value changes.
Does Anchor Modeling work on an audit file level or on a database level?

(iii)
It is possible for two men to possess different values for a certain property, for the same period of time. Similarly, this can happen for a relationship. A manager wishes to record both of these values. He wants to maintain statistic of bad workers. He also wants online db. The following case is for instance possible in court: One side claims the car in an accident was blue, the other claims it was red, while the police claims the car was black. The court requests that all of these three colors be recorded in the database. Obviously, Anchor Modeling cannot solve this.

Vladimir Odrljin Received on Tue Dec 28 2010 - 01:55:16 CET