Relational Model- Integrity

Question 1

Database integrity

Answer 1

The configuration of data values in a database should reflect reality at any given point in time.
Accurate, consistent, complete (meet data quality standards)

Question 2

Enforcing data integrity

Answer 2

Through Integrity rules through
Candidate keys and foreign keys

Question 3

Candidate key

Answer 3

A candidate key has both the uniqueness property and the irreducibility property.

Provides the tuple-level addressing mechanism (helps us find the exact tuple we want in a relational system)

Question 4

Uniqueness property

Answer 4

No two distinct tuples in the relation have the same value for the candidate key. One primary key.

Question 5

Irreducibility property

Answer 5

No proper subset of candidate keys has the uniqueness property

Question 6

Alternate keys

Answer 6

If there is more than one candidate key the ones that aren’t chosen as the primary keys are the alternate key

Question 7

Why irreducibility

Answer 7

DBMS protects integrity by not allowing inserts of duplicate candidate key values.