4NF is designed to cope with :
(a). Multi-valued dependency
(b). Join dependency
(c). Transitive dependency
(d). None of these
Answer: Multi-valued dependency
What is Multi-valued dependency?
A multivalued dependency consists of at least two attributes that are dependent on a third attribute that’s why it always requires at least three attributes.
Exercise:
“The table is with more than one multi-valued dependency”. Solve the problem to ensure 4th normal form
STUDENT | HOBBY | LANGUAGE |
1 | Cricket | English |
1 | Painting | Urdu |
2 | Cricket | Hindi |
2 | Painting | English |
Solution
STUDENT | HOBBY |
1 | Cricket |
1 | Painting |
2 | Singing |
Table 1: Hobby table with just one multi-valued dependency
STUDENT | LANGUAGE |
1 | English |
1 | Urdu |
2 | Hindi |
Table 2: Language table with just one multi-valued dependency
3NF is designed to cope with :
(a). Multi-valued dependency
(b). Join dependency
(c). Transitive dependency
(d). None of these
Answer: Transitive dependency
What is Transitive dependency?
Transitive dependency means that a non-prime attribute A( other than the candidate key) depends on another non-prime attribute B and that B is entirely dependent on the candidate key.
SPECIALIZATION CODE | SPECIALIZATION NAME | COURSE CODE | COURSE NAME |
1 | Computing | A1 | BATABASE |
2 | Development | A2 | C++ |
3 | Computing | A3 | OPERATING SYSTEM |
4 | Development | A4 | OOP |
SPECIALIZATION CODE | SPECIALIZATION NAME | COURSE CODE |
1 | Computing | A1 |
2 | Development | A2 |
3 | Computing | A3 |
4 | Development | A4 |
COURSE CODE | COURSE NAME |
A1 | BATABASE |
A2 | C++ |
2NF is designed to cope with :
(a). Multi-valued dependency
(b). Partial Functional Dependency
(c). Transitive dependency
(d). None of these
Answer: Partial Functional Dependency
What is Partial Functional Dependency?
Employee name | skill | Current work location |
Elizabeth | Graphic designer | Germany |
Elizabeth | Database | Germany |
Elizabeth | Hand writing | Germany |
Eva | Typing speed | United States |
Robert | Fluent in English | United States |
Robert | Leadership | United States |
Haroon | Typing speed | United States |
After 2NF
Employee name | Current work location | |
Elizabeth | Germany | |
Eva | United States | |
Robert | United States | |
Haroon | United States | |
Employee name | skill | |
Elizabeth | Graphic designer | |
Elizabeth | Database | |
Elizabeth | Hand writing | |
Eva | Typing speed | |
Robert | Fluent in English | |
Robert | Leadership | |
Haroon | Typing speed | |
1NF is designed to cope with :
(a). Multi-valued dependency
(b). Partial Functional Dependency
(c). Transitive dependency
(d). Repeating groups
Answer: Repeating groups
What is a Repeating group?
A repeating group is a group of two or more rows/records for an instance of an entity.
Roll No | Name | Marks |
1 | Robert | 77 |
2 | Basit | 90 |
3 | Elizabeth | 44 |
2 | Basit | 70 |
After removing the repeating groups;
Roll No | Name | Marks |
1 | Robert | 77 |
2 | Basit | 90 |
3 | Elizabeth | 44 |
Read Tutorials about Normalization in DBMS
- First Normal form in DBMS
- Second normal form Examples in DBMS
- Third normal form
- Boyce-Codd Normal Form (3.5 NF)
- Fourth Normal Form
- Fifth Normal Form (5NF)