GLOSSARY - Concepts of Database Management - page 369

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FROM clause The part of an SQL SELECT command
that indicates the tables in the query.
Front-end machine See client .
Front-end processor See client .
Function See aggregate function.
Functional dependence See functionally dependent .
Functionally dependent Column B is functionally
dependent on column A (or on a collection of col-
umns) if a value for A determines a single value for B
at any one time.
Functionally determines Column A functionally deter-
mines column B if B is functionally dependent on A.
Generalization In UML, the relationship between a
superclass and a subclass.
Global deadlock In a distributed database, deadlock
that cannot be detected solely at any individual site.
GRANT The SQL statement that is used to grant dif-
ferent types of privileges to users of a database.
GROUP BY clause The part of an SQL SELECT com-
mand that indicates grouping.
Grouping The process of creating collections of
records that share some common characteristic.
Growing phase A phase during a database update in
which the DBMS locks all the data needed for a trans-
action and releases none of the locks.
HAVING clause The part of an SQL SELECT com-
mand that restricts the groups to be displayed.
Heterogeneous DDBMS A distributed DBMS in
which at least two of the local DBMSs are different
from each other.
HIPAA (Health Insurance Portability and
Accountability Act) A federal law enacted in 1996
that specifies the rules for storing, handling, and pro-
tecting health-care transactions.
Homogeneous DDBMS A distributed DBMS in which
all the local DBMSs are the same.
Hot site A backup site that an organization can
switch to in minutes or hours because the site is com-
pletely equipped with duplicate hardware, software,
and data that the organization uses.
HTML (Hypertext Markup Language) A language
used to create Web pages and derived from SGML.
HTTP (Hypertext Transfer Protocol) The data com-
munication method used by Web clients and Web
servers to exchange data on the Internet.
Hyperlink A tag in a Web page that links one Web
page to another or links to another location in the
same Web page.
Hypertext Markup Language See HTML .

Hypertext Transfer Protocol See HTTP .
IDEF1X A type of E-R diagram; or, technically, a lan-
guage in the IDEF (Integrated Definition) family of lan-
guages that is used for data modeling.
Identifying relationship A relationship that is neces-
sary for identification of an entity.
IIS (Internet Information Services) A Microsoft Web
server package that comes with many versions of its
operating systems.
Incomplete category In IDEF1X, a collection of sub-
types with the property that there are elements of the
supertype that are not elements of any subtype.
Independent entity An entity that does not require a
relationship to another entity for identification.
Index A file that relates key values to records that
contain those key values.
Index key The field or fields on which an index
is built.
Information-level design The step during database
design in which the goal is to create a clean, DBMS-
independent design that will support all user
requirements.
Inheritance The property that a subclass inherits the
structure of the class as well as its methods.
INSERT The SQL command to add new data to a
table. After the words INSERT INTO , you list the
name of the table, followed by the word VALUES .
Then you list the values for each of the columns in
parentheses.
INTEGER The SQL data type for integer data.
Integrity A database has integrity if the data in it
satisfies all established integrity constraints.
Integrity constraint A rule that must be followed by
data in a database.
Integrity rules See entity integrity, legal-values
integrity, and referential integrity .
Intelligent key A primary key that consists of a col-
umn or collection of columns that is an inherent char-
acteristic of the entity.
Internet A worldwide collection of millions of inter-
connected computers and computer networks that
share resources.
Internet Information Services (IIS) See IIS .
Interrelation constraint A constraint that involves
more than one relation.
INTERSECT The relational algebra command for
performing the intersection of two tables.
Intersection When comparing tables, an intersection
is a new table containing all rows that are in both
original tables.