1. If a relational database table is in Boyce-Codd normal form, it is also in a.

Question

1. If a relational database table is in Boyce-Codd normal form, it is also in

a.   the first normal form.

b.   the second normal form.

c.   the third normal form.

d.   all of a., b., and c.

2. Which of the following statement(s) is(are) correct?

a.   Multi-level index is designed to reduce the search cost of index part with a reduction ratio of logarithm function.

b.   Multi-level index is guaranteed to have the search cost proportional to the number of levels inmulti-level index.

c.   Both a. and b. are correct.

d.   Neither a. nor b. is correct.

3. A join path (or join condition) used for a join operation, in general,

a. represents a relationship inherited from E-R model representation of a database schema.

b involves a primary key and a foreign key.

c. implies a referential integrity constraint.

d. all of a., b., and c.

Explanation / Answer

1)

1st normal form:
Each cell in table should contain single value.
All records needs to be unique.

2nd normal form:
Be in 1st normal form.
There shold be Single Column Primary Key

3rd normal form:
Be in 2nd normal form
It should containno transitive functional dependencies.

Boyce Codd normal form (BCNF)
It is an advance version of 3NF that’s why it is also referred as 3.5NF.For every functional dependency there should be the super key of the table.

Hence Ans: D.

2) Ans: C

Since multi level is introdused to reduse the cost of searching the blocking factor of the index which is bigger than 2!.

3)Ans:D

Because with join operaion above mentioned three statements shold satisfy.

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