Database Management System . it's a lad activity.

Database Management System And in it we learn about Lab system.

1. Database
Management
System

2. A relation is in 2
nd
normal form iff
it is in the first normal form and all
non key attributes are fully
functionally dependent on key, that
is, there is no partial dependency
Second Normal Form

3. Second Normal Form
CLASS(crId, stId, stName, fId, room, grade)
crId, stId stName, fId, room, grade
stId stName crId fId, room

4. Anomalies
Redundancy
Insertion Anomaly
Deletion Anomaly
Updation Aomaly

5. Anomalies
crIdstIdstName fIdroomgrade
C3456S1020Suhail DarF2345104B
C5678S1020Suhail DarF4567106
C3456S1038Shoaib AliF2345104A
C5678S1015Tahira EjazF4567106B

6. Second Normal Form
Relation is decomposed based on the FDs
CLASS(crId, stId, stName, fId, room, grade)
crId, stId stName, fId, room, grade
stId stName crId fId, room
STD(stId, stName)
COURSE(crId, fId, room)
CLASS(crId, stId, grade)

7. Second Normal Form
Each of these tables is in second
normal form
Free of anomalies due to partial
dependency

8. Third Normal Form
A table is in third normal form
(3NF) iff it is in 2NF and there is
no transitive dependency, that is,
no non-key attribute is dependent
on another non-key attribute

9. Transitive Dependency
STD(stId, stName, stAdr, prName, prCrdts)
stId stName, stAdr, prName, prCrdts
prName prCrdts

10. Anomalies
stIdstName stAdrprNameprCrdts
S1020Sohail DarI-8 IslamabadMCS 64
S1038Shoaib AliG-6 IslamabadBCS 132
S1015Tahira EjazL Rukh Wah MCS 64
S1015Tahira EjazL Rukh Wah MCS 64
S1018Arif ZiaE-8, Islamabad.BIT 134

11. Third Normal Form
STD(stId, stName, stAdr, prName, prCrdts)
stId stName, stAdr, prName, prCrdts
prName prCrdts
STD (stId, stName, stAdr, prName)
PROGRAM (prName, prCrdts)

12. 3NF Relations
Each of the table is in 3NF
Free of all anomalies

13. Boyce-Codd Normal Form
A general form of 3NF
Every relation in BCNF is in 3NF
vice-versa is not always true
3NF is checked in steps, BCNF
checked directly

14. BCNF
A table is in BCNF if every
determinant is a candidate key
Situation when table in 3NF is not
in BCNF
A non-key determines a part of
the composite primary key

15. BCNF
FACULTY(fId, dept, office, rank, dateHired)
fId, dept office, rank, dateHired
office dept
Table is in 3NF, not in BCNF since the office is not
a candidate key
Generates multiple overlapping candidate keys so
we have fId, office dept, rank, dateHired

16. BCNF
We decompose the table again to
bring it into BCNF
FACULTY (fId, dept, office, rank, dateHired)
FACULTY(fId, office, rank, dateHred)
OFFICE(office, dept)

17. Higher Normal Forms
After BCNF fourth, fifth and domain-key
normal forms exist
4NF deals with multivalued dependency,
fifth deals with possible lossless
decompositions, DKNF reduces further
chances of any possible inconsistency