O

object

Anything that can be created or manipulated with SQL, for example, tables, views, indexes, or packages.

ODBC

See [Open Database Connectivity]

ODBC driver

A driver that implements ODBC function calls and interacts with a data source.

offline backup

A backup of the database or table space that is made while the database or table space is not being accessed by applications. During an offline backup, the backup database utility acquires exclusive use of the database until the backup is complete.

offline maintenance

Maintenance activities that can occur only when user access to a database is interrupted.

offline restoration

A restoration of a copy of a database or table space from a backup. The restore database utility has exclusive use of the database until the restore is completed.

OLAP

See [online analytical processing]

OLTP

See [online transaction processing]

on-demand business

An enterprise whose business processesintegrated end to-end across the company and with key partners, suppliers and customerscan respond with speed to any customer demand, market opportunity, or external threat.

online analytical processing (OLAP)

In the DB2 OLAP Server, a multidimensional, multi-user, client-server computing environment for users who need to analyze consolidated enterprise data in real time. OLAP systems feature zooming, data pivoting, complex calculations, trend analysis, and modeling.

online transaction processing (OLTP)

A class of program that facilitates and manages transaction-oriented applications, typically for data entry and retrieval transactions in a number of industries, including banking, airlines, mail order, supermarkets, and manufacturers.

online backup

A backup of the database or table space that is made while the database or table space is being accessed by other applications.

online index creation

The process of creating a new index while allowing the underlying table and any previously existing indexes to be read and updated by concurrent transactions.

online index reorganization

Reorganizing indexes on a table while allowing the table and existing indexes to be read and updated by concurrent transactions.

online maintenance

Maintenance activities that can occur while users are connected to a database.

online restoration

A restoration of a copy of a table space while applications are able to access the tables in other table spaces.

Open Database Connectivity (ODBC)

An application programming interface (API) that allows access to database management systems by using callable SQL, which does not require the use of an SQL preprocessor. The ODBC architecture lets users add modules, called database drivers, that link the application to their choice of database management systems at runtime. Applications do not need to be linked directly to the modules of all the supported database management systems.

operand

An entity on which an operation is performed.

operator

An action that must be performed on data, the output from a table, or an index when the access plan for an SQL statement is executed.

optimized SQL text

SQL text, produced by the explain facility, that is based on the query actually used by the optimizer to choose the access plan. This query is supplemented and rewritten by the various components of the SQL compiler during statement compilation. The text is reconstructed from its internal representation and differs from the original SQL text. The optimized statement produces the same result as the original statement.

outer join

(1) A join method in which a column that is not common to all of the tables being joined becomes part of the result table.

(2) The result of a join operation that includes the matched rows of both tables that are being joined and preserves some or all of the unmatched rows of the tables being joined.

overflow record

An updated record that is too large to fit on the page it is currently stored in. The record is copied to a different page and its original location is replaced with a pointer to the new location.

overloaded function name

A function name for which multiple functions exist within a function path or schema. Those within the same schema must have different signatures.

ownership privilege

Control privilege that allows all privileges for the owned data object.