Database Management Extra 7

Question 1

A key attribute; that is, an attribute that is part of a key or is the whole key.

Answer 1

Prime Attribute

Question 2

A condition by which a dependent table’s foreign key must have either a null entry or a matching entry in the related table.

Answer 2

Referential Integrity

Question 3

A key used strictly for data retrieval purposes. For example, customers are not likely to know their customer number (primary key), but the combination of last name, first name, middle initial, and telephone number will probably match the appropriate table row.

Answer 3

Secondary Key

Question 4

A part of mathematical science that deals with sets, or groups of things, and is used as the basis for data manipulation in the relational model.

Answer 4

Set Theory

Question 5

An attribute or attributes that uniquely identify each entity in a table.

Answer 5

Superkey

Question 6

An index in which the index key can have only one associated pointer value (row).

Answer 6

Unique Index

Question 7

A property that assigns a specific value to connectivity and expresses the range of allowed entity occurrences associated with a single occurrence of the related entity.

Answer 7

Cardinality

Question 8

An attribute that can be further subdivided to yield additional attributes. For example, a phone number such as 615-898-2368 may be divided into an area code (615), an exchange number (898), and a four-digit code (2368).

Answer 8

Composite Attribute

Question 9

In ER modeling, a key composed of more than one attribute.

Answer 9

Composite Identifier

Question 10

A property of an entity that can exist apart from one or more related entities. Such a table must be created first when referencing an existence-dependent table.

Answer 10

existence-independent