Database Reference
In-Depth Information
Figure 2.16. A more complex model showing two different lineups of the same band
With this model, you can easily find all of the albums recorded by (any lineup of) The Tax
Evaders:
ButyoucouldjustaseasilyqueryforjustthosealbumsonwhichRitchieMacNeiceplayed
drums:
The
invariant
information in this graph is that there exists a band called The Tax
Evaders—it keeps its identity even though its membership
varies
. You can represent vari-
ations in the composition of The Tax Evaders using nodes that represent its states at dif-
