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Time and Relational Theory by Nikos Lorentzos, Hugh Darwen, C.J. Date

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Chapter 10

The PACK and UNPACK Operators II: The Multiattribute Case

Although the concept of packing and unpacking relations is essentially straightforward (at least when the operation is performed on the basis of just a single interval attribute), it turns out that the concept has a variety of implications and ramifications—not all of which are immediately obvious—when the operation is performed on the basis of N such attributes when N is not equal to 1. This chapter investigates such matters in depth. In particular, it shows how those investigations lead to an important concept of equivalence among relations and to a novel concept of redundancy in relations with interval attributes.

Keywords

UNPACK; PACK; unpacked form; packed form; equivalence ...

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