Exam 9: Designing Databases

In a relational table,each row is unique and uniqueness is guaranteed because the relation has a non-empty primary key value.

Which relation is created by placing the primary key of the entity on the one side of the relationship as a foreign key in the relation for the entity on the many side?

A(n)________ is an attribute (or combination of attributes)whose value is unique across all occurrences of a relation.

A(n)________ is a file organization in which rows are stored either sequentially or non-sequentially,and an index is created that allows software to locate individual rows.

The capability to split a table into separate sections,often called ________,is possible with most relational database products.

Which relation is created with a composite primary key using the primary keys of the related entities and additional primary key attributes associated with the relationship or associative entity,plus any non-key attributes of the relationship or associative entity?

Which relation is created with a composite primary key (which includes the primary key of the entity on which this weak entity depends)and non-key attributes?

________ database design is driven not only from the previously developed E-R data model for the application or enterprise but also from form and report layouts.

In most situations,many physical database design decisions are implicit or eliminated when we choose the ________ technologies to use with the application.

Logical database design is driven not only from the previously developed E-R data model for the application or enterprise but also from form and report layouts.

A relation is a named,two-dimensional table of data and each relation (or table)consists of a set of named columns and an arbitrary number of unnamed rows.

What is data type? Why is it important to a designer?

Each entity type in the E-R diagram becomes a relation.The identifier of the entity type becomes the ________ of the relation,and other attributes of the entity type become non-primary key attributes of the relation.

When two 3NF relations are merged to form a single relation,dependencies between non-keys may result.

A well-structured relation is a relation that contains a minimum amount of redundancy and that allows users to insert,modify,and delete the rows without error or inconsistencies and is also known as a ________.

A(n)________ is a coding scheme recognized by system software for representing organizational data.

While representing an entity,each non-key attribute of the entity type becomes a key attribute of the relation.

A unary relationship is a relationship between the instances of a ________ entity type,which are also called recursive relationships.

Each relationship in an E-R diagram must be represented in the relational database design and how we represent a relationship depends on its nature.

Logical and ________ database design is typically performed in parallel with other systems design steps.