3401. If an entity appears in only one relationship then it is
a 1:1 relationship
a 1:N relationship
a N:1 relationship
a N:M relationship
Correct answer: (A) a 1:1 relationship
3402. Relations are used in logical database design because
sound theory of relations facilitates systematic design of relational databases
they are very popular
they are flat files and easy to store and retrieve from computer's memory
E-R diagrams allow design of relations
i and ii
i and iii
ii and iii
iii and iv
Correct answer: (B) i and iii
340. A relation is said to be in 1NF if
there is no duplication of data
there are no composite attributes in the relation
there are only a few composite attributes
all attributes are of uniform type
Correct answer: (B) there are no composite attributes in the relation
344. A relation is said to be in 2 NF if
it is in 1 NF
non-key attributes dependent on key attribute
non-key attributes are independent of one another
if it has a composite key, no non-key attribute should be dependent on part of the composite key
i, ii, iii
i and ii
i, ii, iv
i, iv
Correct answer: (C) i, ii, iv
345. Boye Codd Normal Form (BCNF) is needed when
two non-key attributes are dependent
there is more then one possible composite key
there are two or more possible composite overlapping keys and one attribute of a composite key is dependent on an attribute of another composite key
there are two possible keys and they are dependent on one another
Correct answer: (C) there are two or more possible composite overlapping keys and one attribute of a composite key is dependent on an attribute of another composite key