Database Management Systems Exam 1
Questions With Correct Answers
What are the 5 SQL built in functions? - CORRECT ANSWER✔✔-COUNT
SUM
AVG
MIN
MAX
Entity - CORRECT ANSWER✔✔-some identifieable thing that users want to track.
Relation - CORRECT ANSWER✔✔-a two-dimensional table that has certain characteristics
Characteristics of a relation - CORRECT ANSWER✔✔-- each relation in a database has a unique
name
- rows contain data about a specific instance of an entity
- columns contain data about attributes of the entity class
- all entries in a column are of the same kind
- each column in a given table has a unique name
- cells of the table hold a single value
- the order of the columns is unimportant
- the order of the rows is unimportant
- no two rows may be identical
, What are two words that can be used interchangably with "Relation" - CORRECT ANSWER✔✔-
Table
File
What are two words that can be used interchangably with "Attribute" - CORRECT ANSWER✔✔-
Column
Field
What are two words that can be used interchangably with "Tuple" - CORRECT ANSWER✔✔-Row
Record
Functional Dependency - CORRECT ANSWER✔✔-occurs when the value of one (set of)
attribute(s) determines the value of a second (set of) attribute(s)
if A > (B,C) then A > B and A > C
if (A,B) > C then neither A nor B determines C by itself
What makes a determinant value unique? - CORRECT ANSWER✔✔-a determinant is unique in a
relation if and only if, it determines every other column in the relation.
You cannot find the determinant of all functional dependencies simply by looking for unique
values in one column
Key - CORRECT ANSWER✔✔-a combination of one or more columns that is used to identify
rows in a relation.
Composite key - CORRECT ANSWER✔✔-a key that consists of two or more columns
Candidate key - CORRECT ANSWER✔✔-a key that determines all of the other columns in a
relation
Questions With Correct Answers
What are the 5 SQL built in functions? - CORRECT ANSWER✔✔-COUNT
SUM
AVG
MIN
MAX
Entity - CORRECT ANSWER✔✔-some identifieable thing that users want to track.
Relation - CORRECT ANSWER✔✔-a two-dimensional table that has certain characteristics
Characteristics of a relation - CORRECT ANSWER✔✔-- each relation in a database has a unique
name
- rows contain data about a specific instance of an entity
- columns contain data about attributes of the entity class
- all entries in a column are of the same kind
- each column in a given table has a unique name
- cells of the table hold a single value
- the order of the columns is unimportant
- the order of the rows is unimportant
- no two rows may be identical
, What are two words that can be used interchangably with "Relation" - CORRECT ANSWER✔✔-
Table
File
What are two words that can be used interchangably with "Attribute" - CORRECT ANSWER✔✔-
Column
Field
What are two words that can be used interchangably with "Tuple" - CORRECT ANSWER✔✔-Row
Record
Functional Dependency - CORRECT ANSWER✔✔-occurs when the value of one (set of)
attribute(s) determines the value of a second (set of) attribute(s)
if A > (B,C) then A > B and A > C
if (A,B) > C then neither A nor B determines C by itself
What makes a determinant value unique? - CORRECT ANSWER✔✔-a determinant is unique in a
relation if and only if, it determines every other column in the relation.
You cannot find the determinant of all functional dependencies simply by looking for unique
values in one column
Key - CORRECT ANSWER✔✔-a combination of one or more columns that is used to identify
rows in a relation.
Composite key - CORRECT ANSWER✔✔-a key that consists of two or more columns
Candidate key - CORRECT ANSWER✔✔-a key that determines all of the other columns in a
relation
