Databases
Database Analogies
Collected by Giovanna Guerrini — Lecture Notes
Conceptual modeling
Anything else
helps students understanding the role of external/mixed identifiers referring to person identities (movie character)
| Symbol | Concept |
|---|---|
| weak entity instance | person (Jason Bourne) |
| identifier | person's identity |
how cardinality constraints and external/mixed identifiers for weak entities are related (case of optional participation to identifying relationship)
If a weak entity instance were allowed not to relate to a strong entity instance (optional participation to the identifying relationship) it is like a person with lost identity, as Jason Bourne
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A notional machine is a pedagogic device to assist the understanding of some aspect of programs or programming. To something along the lines of A notional machine is a pedagogical tool designed to support the understanding of programs, programming, and other aspects of computing such as databases.
