DB2 REXX SQL for VM/ESA^(R): Installation and Reference

Glossary

This glossary includes terms and definitions from:

• The American National Standard Dictionary for Information Systems ANSI X3.172-1990, copyright 1990 by the American National Standards Institute (ANSI). Copies may be purchased from the American National Standards Institute, 1430 Broadway, New York, New York 10018. Definitions are identified by the symbol (A) after the definition.
• The Information Technology Vocabulary developed by Subcommittee 1, Joint Technical Committee 1, of the International Organization for Standardization and the International Electrotechnical Commission (ISO/IEC JTC1/SC1). Definitions of published parts of this vocabulary are identified by the symbol (I) after the definition; definitions taken from draft international standards, committee drafts, and working papers being developed by ISO/IEC JTC1/SC1 are identified by the symbol (T) after the definition, indicating that final agreement has not yet been reached among the participating National Bodies of SC1.

access

The manner in which files or data sets are referred to by a computer.

access module

See package.

application server

The database manager component that receives and processes database requests issued by the application requester.

authority

See CONNECT authority, RESOURCE authority, and DBA authority.

authorization

The right granted to a user to communicate with or make use of a computer system.

authorization ID

(1) A character string that designates a set of privileges. The authorization ID of a statement is used by the database manager for authorization checking and as an implicit qualifier for the names of tables, views, and indexes. (2) A user or a group of users. Contrast with user ID.

byte

A unit of storage consisting of eight adjacent binary digits operated on as a unit and constituting the smallest addressable unit in the system.

catalog

A set of tables that contain descriptions of objects such as tables and views, and other entities such as conversion tables and authorization IDs maintained by the database manager.

catalog table

A table maintained dynamically by the DB2 Server for VSE & VM database manager containing information about objects such as tables and views, and other entities such as conversion tables and authorization IDs defined to the database manager.

character

(1) A letter, digit, or other symbol in a data character set that is part of the data. (2) A data type in SQL.

CMS

See conversational monitor system.

column

The vertical component of a table. A column has a name and a particular data type (for example, character, decimal, or integer).

command

A request for system action. ISQL and DBS Utility commands can be used with the DB2 Server for VSE & VM database manager. Contrast with statement. DB2 RXSQL commands do not have SQL equivalents.

commit

(1) The operation that terminates a unit of work by releasing locks so that the database changes made by that unit of work can be perceived by other processes. (2) The process that allows data changes to be made permanent. When a commit occurs, other applications can reference the just-committed data.

CONNECT authority

The authority to use database functions, such as SQL statements, on a database.

constant

Data that has an unchanging, predefined value to be used in processing. Constants are classified as string constants or numeric constants. Synonymous with literal. Contrast with variable.

control program (CP)

A component of a VM system that manages the resources of a single computer so multiple computing systems appear to exist. Each virtual machine is the functional equivalent of an IBM System/370^(TM) or System/390^(R) system.

conversational monitor system (CMS)

A virtual machine operating system that provides general interactive time sharing, problem solving, and program development capabilities, and operates only under control of the VM control program.

CP

See control program.

DASD

See direct access storage device.

database machine

A virtual machine that has access to SQL/DS^(TM) code and a database. The database machine controls access to the database.

database management system (DBMS)

A software system that controls the logical and physical resources and facilities of a database.

database manager

A program product that processes SQL statements.

Database Services utility (DBS utility) Services utility (DBS utility)

An application program supplied with the DB2 Server for VM and DB2 Server for VSE database managers to provide several utility functions,including the loading and unloading of data and packages,and the execution of SQL statements previously saved in a command file.

date

A three-part value that designates a day, month, and year.

DB2 for VM

Short form of DB2 Server for VM.

DBA authority

The authority to perform all SQL operations on all SQL tables. DBA authority includes both CONNECT authority and RESOURCE authority.

DBMS

See database management system.

DBS Utility (Database Services Utility)

See Database Services Utility.

dbspace

A logical allocation of space in a storage pool contained in a database. Contains one or more tables and their associated indexes.

default

Pertaining to an attribute, value, or option that is assumed when none is explicitly specified.

direct access storage device (DASD)

A device in which access to data is independent of the location of the data.

directory

A list of identifiers that map corresponding items of data. For example, an SQL/DS directory maps dbspaces to addresses on a physical device.

distributed relational database architecture (DRDA)

Pertaining to an IBM connection protocol for the access and use of distributed relational data wherever it resides in an interconnected network of relational database products.

DRDA (distributed relational database architecture)

See distributed relational database architecture.

EXEC

A CMS file with a file type of EXEC. It contains a series of commands or instructions that are executed when you enter the filename of the EXEC file.

file mode

A 2-character CMS file identifier field comprised of a file mode letter (A through Z) followed by the file mode number (0 through 6). The file mode letter indicates the minidisk or SFS directory on which the file resides. The file mode number indicates the access mode of the file.

file type

A 1- to 8-character alphanumeric field, comprised of A through Z, 0 through 9, and special characters $ # @ + - (hyphen) : (colon) _ (underscore), that is used as a descriptor or as a qualifier of the file name field in the CMS file identifier.

Interactive Structured Query Language (ISQL)

A facility of the SQL/DS system that provides online data query and report writing support.

ISQL

See Interactive Structured Query Language.

K

Kilobyte

Kanji

A graphic character set consisting of symbols used in Japanese ideographic alphabets.

keyword

In programming languages, a predefined word that has a special meaning or function. For example, in the DB2 Server for VM and DB2 Server for VSE database managers, SELECT is the keyword used to retrieve data from a table.

kilobyte

1 024 bytes

literal

A string whose value is given by the content of the string itself. For example, the numeric literal 7 has the value 7. Synonym for constant.

load

To transfer data from one medium to another; for example, to transfer data from a sequential file to a database, or to transfer a program from storage to computer memory.

logical unit of work (LUW)

A recoverable sequence of operations within an application process. At any time, an application process is a singleunit of work, but the life of an application process can involve many units of work as a result of commit or rollback operations.

LUW

See logical unit of work (LUW).

minidisk

Logical division of a physical direct access storage device.

multiple user mode

A mode of operating the database manager in which one or more users or application programs can access the database at the same time. Contrast with single user mode.

NLS

National language support.

owner

The authorization ID associated with an SQL object.

package

A control structure produced during program preparation that is used to execute SQL statements. module.

parameter

A variable that is given a constant value for a specified operation.

private dbspace

A logical space in a DB2 Server for VM database owned by one user.

public dbspace

A logical space in a DB2 Server for VM database that is accessible to many users.

rc

See return code.

RESOURCE authority

The authority to create tables in a public dbspace and to acquire a private dbspace.

return code

A string, typically a number passed in an implementation-dependent way, that conveys some information about the command that has been executed. Return codes usually indicate the success or failure of the command but can also be used to represent other information.

REXX

A procedural language that allows programs and algorithms to be written in a clear and structured way.

row

A horizontal component of a table. A row consists of a sequence of values, one for each column of the table.

RXSQL

DB2 REXX SQL for VM/ESA.

scroll

To move a display image vertically or horizontally to view data that is not otherwise visible in a display or window.

SFS directory (shared file system directory)

See shared file system directory.

shared file system directory (SFS directory)

A part of CMS that allows users to organize their files into groups known as directories, and to selectively share those files and directories with other users.

single user mode

A mode of operation in which the database manager and one application run in the same virtual machine. No other application programs or userscan access the database at the same time. Contrast with multiple user mode.

SQLCA

See SQL communication area (SQLCA).

SQLCODE

A code set by the database manager after an SQL statement is executed to indicate the success or failure of the SQL statement. The value returned in the SQLCODE is specific to the DB2 Server for VSE & VM system. Contrast with SQLSTATE. See also SQL communication area.

SQL communication area (SQLCA)

A set of variables that provides an application program with information about the execution of its SQL statements.

SQL/DS

See Structured Query Language/Data System.

SQLSTATE

A code set by the database manager after an SQL statement is executed to indicate the success or failure of the SQL statement. Contrast with SQLCODE.

statement

An instruction in a program or procedure. A language construct that represents a step in a sequence of actions. Contrast with command. RXSQL statements have SQL equivalents.

storage pool

A specific set of available storage areas. These areas are used by the database administrator to control storage of the database. A storage pool contains one or more dbspaces.

Structured Query Language/Data System (SQL/DS)

A standardized language for defining and manipulating data in a relational database. This was the previous product name for DB2 Server for VSE & VM.

table

A named data object consisting of a specified number of columns and any number of unordered rows.

time

A three-part value that designates a time of day in hours, minutes, and seconds.

unit of work

See logical unit of work (LUW).

user ID

A string of characters that uniquely identifies a user to a system. Contrast with authorization ID.

variable

A quantity that can assume any of a given set of values. Contrast with constant.

Virtual Machine (VM)

A functional simulation of a computer and its associated devices. VM manages the computer's resources in such a way that all workstation users have their own virtual machine. All users can work at their virtual machines as though each is the only person using the real computer.

VM

See Virtual Machine.

VM/ESA environment

Virtual Machine/Enterprise Systems Architecture. The 370 feature addresses a maximum of 16 megabytes of virtual storage per virtual machine. The ESA Feature addresses a maximum of 2 gigabytes of virtual storage per virtual machine.