Database Concepts Quiz 1-3

When an equi-join is performed on a table of N rows and a table of M rows, the resulting table has the following number of rows:

A number in the range 0 to M*N

The Union of a table of N rows and of a table of M rows has the following number of rows:

A number in the range N/M (the larger one between N and M) to M+N

When the referential integrity rule is enforced, which one is usually not a valid action in response to the deletion of a row that contains a primary key value referenced elsewhere?

Accept the deletion without any other action

For referential integrity, which of the following statements is correct?

All of the above

A relational algebra operator applied to table Employee and table Department produces the following result: 100 Sales The operator is:

An outer join operator

The ____ receives all application requests and translates them into the complex operations required to fulfill requests.

DBMS

A 1-M relationship is a connection between two tables in which rows of each table can be related to many rows of the other table.

False

A mandatory FK condition produces a strong (identifying) relationship.

False

Union compatibility requires that each table must have the same number of columns, but the corresponding columns can have different data types because the DBMS will convert them during query execution.

False

Which of the following products do not provide an enterprise database?

MS Access

For keys, which of the following statement is not correct?

None of the above

Which of the following statements does not apply to relational databases?

Relational databases have a strong procedural orientation

When loading data into two entities with a 1:M relationship (the many side entity is mandatory), how should the data be loaded?

The 1 side must be loaded first.

A null value indicates:

The absence of a value

A relational algebra operator applied to table Employee and table Department produces the following result: 555 Kearny 300 Marketing That operator is:

The natural join operator

For composite entity, which of the following statement is not correct?

The primary key of an composite entity will always be a composite key.

A one-sided outer join can be useful in preserving rows in the result table in a situation where a table has null values in a foreign key.

True

In a natural join operation, the join columns have the same unqualified name, which is the column name without the table name.

True

The divide operator is more difficult to use than a join because the matching requirement is more stringent.

True

Two tables that are not union compatible can be made union compatible using the project operator.

True

In the context of a database table, the statement "A ____ B" indicates that if you know the value of attribute A, you can look up the value of attribute B.

determines

A ____ database supports data distributed across several different sites.

distributed

The set of possible values for an attribute is a _____.

domain

What is the most common classification applied to a DBMS?

expected type and extent of use

Which of the following would result in a data anomaly?

inconsistent redundant data

Accurate, relevant, and timely ____ is the key to good decision making.

information

Data ____ exists when the same data are stored unnecessarily at different places.

redundancy

A desktop database is a ____ database.

single-user

What is a benefit of using a DBMS?

they help create an environment for end users to have access to more data

A(n) ____ database supports a relatively small number of users (usually fewer than 50) or a specific department within an organization.

workgroup