Exam 3: The Relational Database Model

When you define a table's primary key,the DBMS automatically creates a(n)____ index on the primary key column(s)you declared.

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

A(n)____________________ index is an index in which the index key can have only one pointer value (row)associated with it.

____ combines all rows from two tables,excluding duplicate rows.

A(n)____ join links tables by selecting only the rows with common values in their common attribute(s).

Numeric data are data on which you can perform meaningful arithmetic procedures.

To avoid nulls,some designers use special codes,known as ____________________,to indicate the absence of some value.

Codd's rule of ____________________ states that every value in a table is guaranteed to be accessible through a combination of table name,primary key value,and column name.

A(n)____ is perceived as a two-dimensional structure composed of rows and columns.

A data dictionary contains metadata-data about data.

Any attribute that is part of a key is known as a ____.

A CUSTOMER table's primary key is CUS_CODE.The CUSTOMER primary key column has no null entries,and all entries are unique.This is an example of ____ integrity.

All primary key entries are unique,and no part of a primary key may be ____.

Only a single attribute,not multiple attributes,can define functional dependence.

____,also known as RESTRICT,yields values for all rows found in a table that satisfy a given condition.

A ____ key can be described as a superkey without unnecessary attributes,that is,a minimal superkey.

____________________ relationships cannot be implemented as such in the relational model.

____________________ is the real power behind the relational database,allowing the use of independent tables linked by common attributes.

The relational model's creator,E.F.Codd,used the term relation as a synonym for ____.

The index key can have multiple attributes,this is called a(n)____________________ index.