Logical Database Design

Question 1

Data Model

Answer 1

notation to represent the syntax and semantics of a database

Question 2

Type of data model

Answer 2

relational model

Question 3

Relational database schema

Answer 3

defines:
names of tables
attributes of each table
integrity constraints

Question 4

Relational model structure

Answer 4

in form of relations (tabular)

Question 5

Each relation has

Answer 5

a name, a sequence of attributes, and a set of tuples

Question 6

Relation formal definition

Answer 6

a subset of the cartesian product of the domains of the attribute data types

Question 7

Database schema

Answer 7

finite set of relations

Question 8

Domain

Answer 8

data type of an attribute, determined by the RDBM

Question 9

Scheme

Answer 9

defines a relation and its attributes

Question 10

State

Answer 10

an instance of a relation at a particular time

Question 11

Null value

Answer 11

used to model a variety of real-world scenarios;
can mean:
value exists but is not known
no value exists
attribute is not applicable