Example:
RELATIONAL SCHEMA for PERSON:
PERSON (PERSON_ID: integer, NAME: string, AGE: integer, ADDRESS: String)
RELATION INSTANCE
In this instance, m = 3 and n = 4
|
PERSON_ID
|
NAME
|
AGE
|
ADDRESS
|
|
1
|
Sanjay Prasad
|
35
|
b-4,Modi Nagar
|
|
2
|
Sharad Gupta
|
30
|
Pocket 2, Mayur
Vihar.
|
|
3
|
Vibhu Datt
|
36
|
c-2, New Delhi
|
Therefore current relation state reflects only the valid tuples that show a particular state of the real world. Though, Null values can be assigned for the cases where the values are missing or unknown.