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Consider the following relational schemas for a library database:
Book (Title, Author, Catalog_no, Publisher, Year, Price)
Collection (Title, Author, Catalog_no)
within the following functional dependencies
1. Title, Author → Catalog_no
2. Catalog_no → Title Author Publisher Year
3. Publisher Title Year → Price
Assume {Author, Title} is the key for both schemas. Which of the following statements is true?
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- Both Book and Collection are in BCNF
- Both Book and Collection are in 3 NF only
- Book is in 2 NF and Collection is in 3 NF
- Both Book and Collection are in 2 NF only
- Both Book and Collection are in BCNF
Correct Option: C
We will observe that if all the non-key fields are fully dependent on a whole key then a table would be formed in the Second normal form (2NF).
This table will be in 3NF only when non-key fields are independent on a whole key then a table.
Alternatively, Relation Book: transitivity dependency by 1, 2, 3 statements as given, hence, the relation Book is in 2NF. Relation Collection L: it is in 3 NF as there is fully transitive dependency.
Therefore Book is in 2NF and Collection is in 3NF.
