Databases Reference
In-Depth Information
database table. As a result, the table can be accessed as
a relational table or as an object table and make the
transition to a fully object-oriented environment easier.
Oracle block
See
database block
.
Oracle Enterprise Manager (OEM)
A GUI tool that
allows access, maintenance, and monitoring of mul-
tiple databases or services within a single application.
object-relational database
A relational database
that includes additional operations and components to
support object-oriented data structures and methods.
Oracle Home
A common directory location used to
store the associated program files for a specific
release of the Oracle database software.
OCI (Oracle Call Interface)
A set of library rou-
tines that allows a C application on virtually any
development platform to easily connect to and pro-
cess SQL statements against an Oracle database. The
OCI routines are called as native C library functions;
therefore, no preprocessor is necessary when com-
piling a C application using OCI.
Oracle Universal Installer (OUI)
A GUI-based tool
used to install or uninstall Oracle software compo-
nents and tools.
Oracle's Tuning Methodology
A tuning method
recommended by Oracle Corporation that prioritizes
areas in tuning database performance. The six areas,
in order of priority, are data design, application
design, memory allocation, I/O and physical struc-
tures, resource contention, and underlying platform.
ODBC (Open Database Connectivity)
A set of stan-
dards that allow applications that are not dependent
on any one specific database to process SQL state-
ments against any database that supports SQL.
outer join
A join between two or more tables
returning all the rows in one table whether or not the
second table contains a match on the join condition.
ODBC driver
An interface, usually at the operating-
system level, that supports the connection of an ODBC-
compliant application to a specific database platform.
partitioned table
A table that stores its rows into
smaller and more manageable pieces based on the
values of one or more columns of the table.
one-to-many relationship
A relationship type
between tables where one row in a given table is
related to many other rows in a child table. The
reverse condition, however, is not true. A given row
in a child table is related to only one row in the
parent table.
pattern matching
Comparing a string in a database
column to a string containing wildcard characters.
These wildcard characters can represent zero, one, or
more characters in the database column string.
one-to-one relationship
A relationship type
between tables where one row in a given table is
related to only one or zero rows in a second table.
This relationship type is often used for subtyping.
For example, an EMPLOYEE table may hold the infor-
mation common to all employees, while the
FULLTIME, PARTTIME, and CONTRACTOR tables hold
information unique to full-time employees, part-time
employees, and contractors, respectively. These enti-
ties would be considered subtypes of an EMPLOYEE
and maintain a one-to-one relationship with the
EMPLOYEE table.
PFILE
A text file containing the parameters and
their values for configuring the database and
instance at startup.
physical structures
Structures of an Oracle data-
base, such as datafiles on disk, that are not directly
manipulated by users of the database. Physical struc-
tures exist at the operating system level.
primary key
A column (or columns) in a table that
makes the row in the table distinguishable from every
other row in the same table.
open backup
See
hot backup
.
PRIMARY KEY constraint
A constraint that
uniquely defines each row of a table and prevents
