CS 6400 Exam 2 Hard question test prep

CS 6400 Exam 2 Hard question test prep
Study online at https://quizlet.com/_g2n4sx

1. what many superkeys can be a relation? degree of relation

2. what is a domain? domain is the array of possible val-
ues a attribute can have

3. how is domain different from type? type is the kind of values, while do-
main is the array of values within that
kind. Example: type of 'color' would
have domain of {"red, blue, red.....}

4. Can multiple domains exist in a relation? Yes, example: if multiple integers ex-
isted, then the domain of all posi-
tive/negative integers would be pre-
sent

5. Can multiple primary keys exist? No, but a primary key can consist of
multiple candidate keys, and within
the primary key can exist multiplesu-
perkeys

6. How many unique fields can exist in the follow- 1.) 1
ing: 2.)
candidate key: 3.) 1 or more
superkey:
primary key:

7. In the relation R(A1,A2,A3), how many of the 1.) Do not know because their is no
following can exist? uniqueness constraint
Candidate: 2.)
Superkey:
primary key:

8.

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