Chapter 1 & 2: Database Design Fundamentals
attribute
A characteristic or property of an entity
relational database
A collection of relations
determinant
A column in a table that determines at least one other column
nonkey column
A column that is not part of the primary key
concatenation
A combination of columns
entity-relationship (E-R) diagram
A graphical illustration for database design that uses rectangles for entities and arrows for relationships
candidate key
A minimal collection of columns in a table
entity
A person, place, object, event, or idea for which you want to store and process data
normalization
A process that analyzes a database design to identify the existence of potential problems and implements ways to correct these problems
normal form
A progression that proceeds from first normal form to second normal form to third normal form. A table in a particular normal form possesses a certain desirable collection of properties.
Boyce-Codd normal form (BCNF)
A relation is in Boyce-Codd normal form if it is in second normal form and the only determinants it contains are candidate keys; also called third normal form
one-to-many relationship
A relationship in which one entity is associated with many other entities
record
A row in a table
tuple
A row in a table
first normal form (1NF)
A table that does not contain any repeating groups
second normal form (2NF)
A table that is in first normal form and where no nonkey column is dependent on only a portion of the primary key
third normal form (3NF)
A table that is in second normal form and the only determinants are candidate keys
unnormalized relation
A table that satisfies the definition of a relation except that it might contain repeating groups
relation
A two-dimensional table in which the entries are single valued; each column has a distinct name (or attribute name); all values in a column are values of the same attribute; the order of the rows and columns is immaterial; and each row contains unique values
field
An attribute
update anomaly
An update problem that can occur in a database as a result of a faulty design
functionally determine
Column A functionally determines column B if B is functionally dependent on A
functionally dependent
Column B is functionally dependent on column A (or on a collection of columns) if a value for A determines a single value for B at any one time
redundancy
Duplication of data
repeating group
Multiple entries in an individual location in a table
database design
Process of determining the particular tables and columns that will comprise a database
relationship
The association between entities
primary key
The column or collection of columns that uniquely identifies a given row in a table
qualify
To combine a column name with a table name
