Quiz 2 - 3304

In implementation terms, an entity is existence-dependent if it has a mandatory primary key.

False

Referential integrity and participation are both bidirectional, meaning that they must be addressed in both directions along a relationship.

False

The Crow's Foot notation easily identifies multivalued attributes.

False

The SELECT operator yields a vertical subset of a table.

False

Date attributes contain calendar dates stored in a special format known as the _____ date format.

Julian

The entity relationship model uses the associative entity to represent a(n) _____ relationship between two or more entities.

M:N

_____ relationships can be implemented by creating a new entity in 1:M relationships with the original entities.

M:N

The _____ constraint can be placed on a column to ensure that every row in the table has a value for that column.

NOT NULL

A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.

True

A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship.

True

An entity in the entity relationship model corresponds to a table in the relational environment.

True

Connectivities and cardinalities are established by concise statements known as business rules.

True

In a 1:M relationship, to avoid the possibility of referential integrity errors, the data of the "1" side must be loaded first.

True

In the entity relationship model, a table row corresponds to an entity instance.

True

Relational algebra defines the theoretical way of manipulating table contents using relational operators.

True

The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor and one two-column table (e.g., columns "a" and "b") as the dividend.

True

The entity relationship diagram (ERD) represents the _____ database as viewed by the end user.

conceptual

A derived attribute is indicated in the Chen notation by a _____ that connects the attribute and an entity.

dashed line

Knowing the minimum and maximum number of _____ occurrences is very helpful at the application software level.

entity

An entity is said to be _____-dependent if it can exist in the database only when it is associated with another related entity occurrence.

existence

In a database context, the word _____ indicates the use of the same attribute name to label different attributes.

homonym

According to Codd's _____ rule of relational databases, if the system supports low-level access to the data, users must not be allowed to bypass the integrity rules of the database.

nonsubversion

The existence of a(n) _____ entity indicates that its minimum cardinality is zero.

optional

When the specific cardinalities are not included on the diagram in Crow's Foot notation, cardinality is implied by the use of _____.

symbols

In a database context, a(n) _____ indicates the use of different names to describe the same attribute.

synonym