Revision Quiz

Control who is allowed access to the data;

Ensure that duplicate records are not entered into the table;

Improve the quality of data entered for a specific property;

Prevent users from changing the values stored in the table

Entity

Attribute

Identifier

Relationship

Data View;

Logical View

User View

System View

Entities

Attributes

Identifiers

Relationship

Understand each user’s perspective of data;

Understand the data itself irrespective of the physical representation;

Understand the use of data across application areas;

All of the above

Compound table;

Association class;

Bridge entity;

Iterative super key

Entity integrity

Primary key;

Referential integrity;

Mandatory participation.

Relationship and degree;

Cardinality and relationship;

Degree and cardinality;

Cardinality and participation.

Every tuple of R1 has a distinct value for K;

K cannot have a null value for tuples in R1;

K is a key for some other relation;

K is a Primary key for R1.

Data decomposition;

Normalisation;

Data consistency;

Data redundancy.