Which-one ofthe following statements about normal forms is FALSE?
| A. | BCNF is stricter than 3 NF |
| B. | Lossless, dependency -preserving decomposition into 3 NF is always possible |
| C. | Loss less, dependency - preserving decomposition into BCNF is always possible |
| D. | Any relation with two attributes is BCNF |
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Option: C Explanation : Click on Discuss to view users comments. |
Consider a relation scheme R = (A, B, C, D, E, H) on which the following functional dependencies hold: {A —> B, BC ---> D, E, —> C, D —> Al . What are the candidate keys of R?
| A. | AE, BE |
| B. | AE, BE, DE |
| C. | AEH, BEH, BCH |
| D. | AEH, BEH, DEH |
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Option: D Explanation : Click on Discuss to view users comments. |
The following functional dependcies are given:
AB -> CD, AF —> D, DE --> F, C —> G, F —› E, G --> A
Which one of the following options is false?
| A. | {CF}+ = {ACDEFG} |
| B. | {BG}± = {ABCDG} |
| C. | {AE }+ = {ACDEFG} |
| D. | {AC = {ACDFG} |
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Option: C Explanation : Click on Discuss to view users comments. |
Which one ofthe following statements is FALSE?
| A. | Any relation with two attributes is in BCNF |
| B. | A relation in which every key has only one attributes is in 2NF |
| C. | A prime attribute can be transitively dependent on a key in 3 NF relation |
| D. | A prime attribute can be transitively dependent on a key in a BCNF relation |
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Option: D Explanation : Click on Discuss to view users comments. |
Consider the following relational schemes for a library for a library database:
Book (Title, Author, Catalog_no, Publisher, Year, Price)
Collection (Title, Author, Catalog_no)
Which ofthe following functional dependecies:
I. Title Author —› Catalog no.
II. Catalog_no ---> Title Author Publisher Year
III. Publisher Title Year --> Price.
Assume {Author, Title) is the key for both schemes: which ofthe following statements is true?
| A. | Both Book and collection are in BCNF |
| B. | Both Book and collection are in 3NF only |
| C. | Book is in 2NF and Collection is in 3NF |
| D. | Both Book and Collection are in 2NF only |
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Option: C Explanation : Click on Discuss to view users comments. |
