ISTM 320 EXAM 2

Entity

A person, place, thing, noun - must have a primary key and will have one or more attributes

What to do when we have a many to many relationship?

Create Associative Entity

A binary one-to-many (1:N) relationship in an E-R diagram is represented by adding the primary key attribute (or attributes) of the entity on the one side of the relationship as a(n) ________ in the relation that is on the many side of the relationship.

Foreign key

A(n) ________ is an attribute whose value can be computed from related attribute values.

Derived attribute

The most common format used for data modeling is ________ diagramming.

Entity-Relationship

Entity

Example: Student

Instance

Example: Student ID

A(n) ________ is an attribute that may take on more than one value for each entity instance.

Multi-valued attribute

A(n) ________ is a specification that indicates how many objects participate in a given relationship.

Multiplicity

The result of normalization is that every ________ key attribute depends upon the whole primary key.

Non-primary

________ is a process for converting complex data structures into simple, stable data structures.

Normalization

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.

Primary key

A(n) ________ is an operation that does not have any side effects; it accesses the state of an object but does not alter the state.

Query operation

A(n) ________ is an attribute that must have a value for every entity instance.

Required attribute

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

Two

A recursive relationship is also known as a ________ relationship.

Unary

Which relation is created by placing the primary key of either entity in the relation for the other entity or by doing this for both entities?

Unary 1:1 relationship

Instances

Rows

Attribute

Columns

During logical database design, you must account for every data element on a system input or output form or report and on the ________.

E-R diagram

In logical database modeling and design, we combine normalized data requirements from all user interfaces into one consolidated logical database model; this step is called view ________.

Integration

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

Physical

One purpose of database design is to structure the data in stable structures, called normalized tables, that are not likely to change over time and that have minimal ________.

Redundancy

A common mistake many people make when they are just learning to draw E-R diagrams, especially if they already know how to do data flow diagramming, is to confuse data entities with ________ and relationships with data flows.

Sinks

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 ________.

Table