What are the significant functional dependencies in this relation? (b) What is/are the candidate key(s) of this relation? (c) is this relation in 1NF, 2NF, 3NF, BCNF? And why?
(a) What are the significant functional dependencies in this relation?
(b) What is/are the candidate key(s) of this relation?
(c) is this relation in 1NF, 2NF, 3NF, BCNF? And why?
Functional Dependencies (FD):
It determines the relation between two attributes in database management system.
It used to find difference between good and bad database
It maintain quality of data
Functional dependencies determined by arrow symbol
Example:
Functional dependencies between A and B is determined by
Given Syntax:
If we know the value of borrower_id, we can obtain name, address, request_date, request_amount, loan_amount, repayment_date, replayment_amount.
Candidate key:
It is minimal set of attributes which is uniquely identify a tuple.
Rule for being candidate key:
- Value of candidate key must be unique for every tuple
- Value of candidate key should be not-null for every tuple
- Possible of having more than one candidate key in a relation
- It cab be simple or composite based on the relation
Given Syntax:
Candidate key is borrower_id.
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