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Chapter 5
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Integrity constraints provide a way of ensuring that changes made to the
database by authorized users do not result in a loss of data consistency.
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We saw a form of integrity constraint with E-R models:
- key declarations: stipulation that certain attributes form
a candidate key for the entity set.
- form of a relationship: mapping cardinalities 1-1, 1-many
and many-many.
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An integrity constraint can be any arbitrary predicate applied to
the database.
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They may be costly to evaluate, so we will only consider integrity
constraints that can be tested with minimal overhead.
Page created and maintained by Osmar R. Zaï ane
Last Update:
Mon Oct 16 17:01:17 PDT 1995