SQL*Plus User's Guide and Reference Go to Product Documentation Library
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GLOSSARY


A

account
An authorized user of an operating system or a product (such as Oracle Server or SQL*Forms). Depending on the operating system, may be referred to as ID, User ID, login, etc. Accounts are often created and controlled by a system administrator.
alias
In SQL, a temporary name assigned to a table, view, column, or value within a SQL statement, used to refer to that item later in the same statement or in associated SQL*Plus commands.
alignment
The way in which data is positioned in a field. It may be positioned to the left, right, center, flush/left, flush/right, or flush/center of the defined width of a field.
anonymous block
A PL/SQL program unit that has no name and does not require the explicit presence of the BEGIN and END keywords to enclose the executable statements.
argument
A data item following the command-file name in a START command. The argument supplies a value for a parameter in the command file.
array processing
Processing performed on multiple rows of data rather than one row at a time. In some Oracle utilities such as SQL*Plus, Export/Import, and the precompilers, users can set the size of the array; increasing the array size often improves performance.
ASCII
A convention for using digital data to represent printable characters. ASCII is an acronym for American Standard Code for Information Interchange.
autocommit
A feature unique to SQL*Plus that enables SQL*Plus to automatically commit changes to the database after every successful execution of a SQL command or PL/SQL block. Setting the AUTOCOMMIT variable of the SET command to ON enables this feature. Setting the AUTOCOMMIT variable to n enables this feature after every n successful INSERT, UPDATE or DELETE commands or PL/SQL blocks.

B

bind reference
A reference to a parameter used to replace a single literal value (e.g., a character string, number, or date) appearing anywhere in a PL/SQL construct or a SQL SELECT statement. For a bind reference, you must precede the parameter name with a colon (:).
bind variable
A variable in a SQL statement that must be replaced with a valid value, or the address of a value, in order for the statement to successfully execute.
bit
The smallest unit of data. A bit only has two possible values, 0 or 1. Bits can be combined into groups of eight called bytes; each byte represents a single character of data. See also byte.
block
In PL/SQL, a group of SQL and PL/SQL commands related to each another through procedural logic.
body
A report region that contains the bulk of the report (text, graphics, data, and computations).
break
An event, such as a change in the value of an expression, that occurs while SQL*Plus processes a query or report. You can direct SQL*Plus to perform various operations, such as printing subtotals, whenever specified breaks occur.
break column
A column in a report that causes a break when its value changes and for which the user has defined break operations.
break group
A group containing one or more break columns.
break hierarchy
The order in which SQL*Plus checks for the occurrence of breaks and triggers the corresponding break operations.
break order
Indicates the order in which to display a break column's data. Valid options are Ascending and Descending.
break report
A report that divides rows of a table into "sets", based on a common value in the break column.
buffer
An area where the user's SQL statements or PL/SQL blocks are temporarily stored. The SQL buffer is the default buffer. You can edit or execute commands from multiple buffers; however, SQL*Plus does not require the use of multiple buffers.
byte
A group of eight sequential bits that represents a letter, number, or symbol (i.e., character). Treated as a unit of data by a computer.

C

CHAR datatype
An Oracle datatype provided for ANSI/ISO compatibility. A CHAR column is a fixed-length column and can contain any printable characters, such as A, 3, &, or blanks, and can have from 1 to 255 characters or can be null.
character
A single location on a computer system capable of holding one alphabetic character or numeric digit. One or more characters are held in a field. One or more fields make up a record, and one or more records may be held in a file or database table.
character string
A group of sequential letters, numerals, or symbols, usually comprising a word or name, or portion thereof.
clause
A part of a SQL statement that does not constitute the full statement; for example, a "WHERE clause".
client
A user, software application, or computer that requests the services, data, or processing of another application or computer (the "server"). In a two-task environment, the client is the user process. In a network environment, the client is the local user process and the server may be local or remote.
column
A vertical space in a database table that represents a particular domain of data. A column has a column name and a specific datatype. For example, in a table of employee information, all of the employees' dates of hire would constitute one column. A record group column represents a database column.
column expression
An expression in a SELECT statement that defines which database column(s) are retrieved. It may be a column name or a valid SQL expression referencing a column name.
column heading
A heading created for each column appearing in a report.
command
An instruction to or request of a program, application, operating system, or other software, to perform a particular task. Commands may be single words or may require additional phrases, variously called arguments, options, parameters, and qualifiers. Unlike statements, commands execute as soon as you enter them. ACCEPT, CLEAR, and COPY are examples of commands in SQL*Plus.
command file
A file containing a sequence of commands that you can otherwise enter interactively. The file is saved for convenience and re-execution. Command files are often called by operating-system specific names. In SQL*Plus, you can execute the command file with the START, @ or @@ commands.
command line
A line on a computer display on which typed in commands appear. An example of a command line is the area next to the DOS prompt on a personal computer. See also prompt.
command prompt
The text, by default SQL>, with which SQL*Plus requests your next command.
comment
A language construct for the inclusion of explanatory text in a program, the execution of which remains unaffected.
commit
To make permanent changes to data (inserts, updates, deletes) in the database. Before changes are committed, both the old and new data exist so that changes can be stored or the data can be restored to its prior state.
computation
Used to perform runtime calculations on data fetched from the database. These calculations are a superset of the kinds of calculations that can be done directly with a SELECT statement. See also formula column.
computed column
See computation.
configuration
In SQL*Net, the set of instructions for preparing network communications, as outlined in the SQL*Net documentation.
configuration files
Files that are used to identify and characterize the components of a network. Configuration is largely a process of naming network components and identifying relationships among those components.
connect
To identify yourself to Oracle by entering your username and password in order to gain access to the database. In SQL*Plus, the CONNECT command allows you to log off Oracle and then log back on with a specified username.
connect string
The set of parameters, including a protocol, that SQL*Net uses to connect to a specific Oracle instance on the network.
current line
In an editor, such as the SQL*Plus editor, the line in the current buffer that editing commands will currently affect.

D

database
A set of operating system files, treated as a unit, in which an Oracle Server stores a set of data dictionary tables and user tables. A database requires three types of files: database files, redo log files, and control files.
database administrator (DBA)
(1) A person responsible for the operation and maintenance of an Oracle Server or a database application. The database administrator monitors its use in order to customize it to meet the needs of the local community of users. (2) An Oracle username that has been given DBA privileges and can perform database administration functions. Usually the two meanings coincide. There may be more than one DBA per site.
database link
An object stored in the local database that identifies a remote database, a communication path to the remote database, and optionally, a username and password for it. Once defined, a database link can be used to perform queries on tables in the remote database. Also called DBlink. In SQL*Plus, you can reference a database link in a DESCRIBE or COPY command.
database object
Something created and stored in a database. Tables, views, synonyms, indexes, sequences, clusters, and columns are all examples of database objects.
database specification
An alphanumeric code that identifies a database, used to specify the database in SQL*Net operations and to define a database link. In SQL*Plus, you can reference a database specification in a COPY, CONNECT, or SQLPLUS command.
database string
A string of SQL*Net parameters used to indicate the network prefix, the host system you want to connect to, and the system ID of the database on the host system.
Data Control Language (DCL)
The category of SQL statements that control access to the data and to the database. Examples are the GRANT and REVOKE statements. Occasionally DCL statements are grouped with DML statements.
Data Definition Language (DDL)
The category of SQL statements that define or delete database objects such as tables or views. Examples are the CREATE, ALTER, and DROP statements.
data dictionary
A comprehensive set of tables and views automatically created and updated by the Oracle Server, which contains administrative information about users, data storage, and privileges. It is installed when Oracle is initially installed and is a central source of information for the Oracle Server itself and for all users of Oracle. The tables are automatically maintained by Oracle. It is sometimes referred to as the catalog.
Data Manipulation Language (DML)
The category of SQL statements that query and update the database data. Common DML statements are SELECT, INSERT, UPDATE, and DELETE. Occasionally DCL statements are grouped with DML statements.
data security
The mechanisms that control the access and use of the database at the object level. For example, data security includes access to a specific schema object and the specific types of actions allowed for each user on the object (e.g., user SCOTT can issue SELECT and INSERT statements but not DELETE statements using the EMP table). It also includes the actions, if any, that are audited for each schema object.
datatype
(1) A standard form of data. The Oracle datatypes are CHAR, VARCHAR2, DATE, NUMBER, LONG, RAW, and LONG RAW; however, the Oracle Server recognizes and converts other standard datatypes. (2) A named set of fixed attributes that can be associated with an item as a property. Data typing provides a way to define the behavior of data.
DATE datatype
A standard Oracle datatype used to store date and time data. Standard date format is DD-MMM-YY, as in 01-JAN-89. A DATE column may contain a date and time between January 1, 4712 BC to December 31, 4712 AD.
DBA
See Database Administrator.
DCL
See Data Control Language.
DDL
See Data Definition Language.
default
A clause or option value that SQL*Plus uses if you do not specify an alternative.
default database
See local database.
directory
On some operating systems, a named storage space for a group of files. It is actually one file that lists a set of files on a particular device.
display format
See format.
display width
The number of characters or spaces allowed to display the values for an output field.
DML
See Data Manipulation Language (DML).
DUAL table
A standard Oracle database table named DUAL, which contains exactly one row. The DUAL table is useful for applications that require a small "dummy" table (the data is irrelevant) to guarantee a known result, such as "true."

E

editor
A program that creates or modifies files.
end user
The person for whom a system is being developed; for example, an airline reservations clerk is an end user of an airline reservations system. See also SQL*Plus.
error message
A message from a computer program (e.g., SQL*Plus) informing you of a potential problem preventing program or command execution.
expression
A formula, such as SALARY + COMMISSION, used to calculate a new value from existing values. An expression can be made up of column names, functions, operators, and constants. Formulas are found in commands or SQL statements.
extension
On some operating systems, the second part of the full file specification. Several standard file extensions are used to indicate the type or purpose of the file, as in file extensions of SQL, LOG, LIS, EXE, BAT, and DIR. Called file type on some operating systems.

F

file
A collection of data treated as a unit, such as a list, document, index, note, set of procedures, etc. Generally used to refer to data stored on magnetic tapes or disks. See also filename, extension, and file type.
filename
The name component of a file specification. A filename is assigned by either the user or the system when the file itself is created. See also extension and file type.
file type
On some operating systems, the part of the filename that usually denotes the use or purpose of the file. See extension.
format
Columns contain information in one of four types; users can specify how they want a query to format information it retrieves from character, number, date, or long columns. For example, they can choose to have information of type date appear as 14/08/90, or Tuesday Fourteenth August 1990, or any other valid date format.
format model
A clause element that controls the appearance of a value in a report column. You specify predefined format models in the COLUMN, TTITLE, and BTITLE commands' FORMAT clauses. You can also use format models for DATE columns in SQL date conversion functions, such as TO_DATE.
form feed
A control character that, when executed, causes the printer to skip to the top of a new sheet of paper (top of form). When SQL*Plus displays a form feed on most terminals, the form feed clears the screen.
formula column
Manually-created column that gets its data from a PL/SQL procedure, function, or expression, user exit, SQL statement, or any combination of these.
function
A PL/SQL subprogram that executes an operation and returns a value at the completion of the operation. A function can be either built-in or user-named. Contrast with procedure.

H

heading
In SQL*Plus, text that names an output column, appearing above the column. See also column heading.
host computer
The computer from which you run SQL*Plus.

J

Julian date
An algorithm for expressing a date in integer form, using the SQL function JDATE. Julian dates allow additional arithmetic functions to be performed on dates.
justification
See alignment.

L

label
Defines the label to be printed for the computed value in the COMPUTE command. The maximum length of a COMPUTE label is 500 characters.
local database
The database that SQL*Plus connects to when you start SQL*Plus, ordinarily a database on your host computer. Also called a default database. See also remote database.
log in (or log on)
To perform a sequence of actions at a terminal that establishes a user's communication with the operating system and sets up default characteristics for the user's terminal session.
log off (or log out)
To terminate interactive communication with the operating system, and end a terminal session.
logon string
A user-specified command line, used to run an application that is connected to either a local or remote database. The logon string either explicitly includes a connect string or implicitly uses a default connect string.
LONG datatype
One of the standard Oracle datatypes. A LONG column can contain any printable characters such as A, 3, &, or a blank, and can have any length from 0 to 2 Gigabytes.

N

network
A group of two or more computers linked together through hardware and software to allow the sharing of data and/or peripherals.
null
A value that means, "a value is not applicable" or "the value is unknown". Nulls are not equal to any specific value, even to each other. Comparisons with nulls are always false.
NULL value
The absence of a value.
NUMBER datatype
A standard Oracle datatype. A NUMBER column can contain a number, with or without a decimal point and a sign, and can have from 1 to 105 decimal digits (only 38 digits are significant).

O

operating system
The system software that manages a computer's resources, performing basic tasks such as allocating memory and allowing computer components to communicate.
Oracle RDBMS
The relational database management system (RDBMS) developed by Oracle Corporation. Components of the RDBMS include the kernel and various utilities for use by database administrators and database users.
Oracle Server
The relational database management system (RDBMS) sold by Oracle Corporation. Components of Oracle Server include the kernel and various utilities for use by DBAs and database users.
output
Results of a report after it is run. Output can be displayed on a screen, stored in a file, or printed on paper.
output file
File to which the computer transfers data.

P

packages
A method of encapsulating and storing related procedures, functions, and other package constructs together as a unit in the database. While packages provide the database administrator or application developer organizational benefits, they also offer increased functionality and database performance.
page
A screen of displayed data or a sheet of printed data in a report.
parameter
A substitution variable consisting of an ampersand followed by a numeral (&1, &2, etc.). You use parameters in a command file and pass values into them through the arguments of the START command.
password
A secondary identification word (or string of alphanumeric characters) associated with a username. A password is used for data security and known only to its owner. Passwords are entered in conjunction with an operating system login ID, Oracle username, or account name in order to connect to an operating system or software application (such as the Oracle database). Whereas the username or ID is public, the secret password ensures that only the owner of the username can use that name, or access that data.
PL/SQL
The Oracle procedural language extension of SQL. PL/SQL combines the ease and flexibility of SQL with the procedural functionality of a structured programming language, such as IF ...THEN, WHILE, and LOOP. Even when PL/SQL is not stored in the database, applications can send blocks of PL/SQL to the database rather than individual SQL statements, thereby reducing network traffic.
procedure
A set of SQL and PL/SQL statements grouped together as an executable unit to perform a very specific task. Procedures and functions are nearly identical; the only difference between the two is that functions always return a single value to the caller, while procedures do not return a value to the caller.
prompt
(1) A message from a computer program that instructs you to enter data or take some other action. (2) Word(s) used by the system as a cue to assist a user's response. Such messages generally ask the user to respond by typing some information in the adjacent field. See also command line.

Q

query
A SQL SELECT statement that retrieves data, in any combination, expression, or order. Queries are read-only operations; they do not change any data, they only retrieve data. Queries are often considered to be DML statements.
query results
The data retrieved by a query.

R

RAW datatype
A standard Oracle datatype, a RAW data column may contain data in any form, including binary. You can use RAW columns for storing binary (non-character) data.
RDBMS (Relational Database Management System)
An Oracle Version 6 (and earlier) term. Refers to the software used to create and maintain the system, as well as the actual data stored in the database. See also Relational Database Management System, Server, Oracle Server and Oracle RDBMS.
record
A synonym for row; one row of data in a database table, having values for one or more columns.
Relational Database Management System (RDBMS)
An Oracle Version 6 (and earlier) term. A computer program designed to store and retrieve shared data. In a relational system, data is stored in tables consisting of one or more rows, each containing the same set of columns. Oracle is a relational database management system. Other types of database systems are called hierarchical or network database systems.
remark
In SQL*Plus, a comment you can insert into a command file with the REMARK command.
remote computer
A computer on a network other than the local computer.
remote database
A database other than your default database, which may reside on a remote computer; in particular, one that you reference in the CONNECT, COPY, and SQLPLUS commands.
report
(1) The results of a query. (2) Any output, but especially output that has been formatted for quick reading. In particular, output from SQL*Plus, SQL*Report, or SQL*ReportWriter.
reserved word
(1) A word that has a special meaning in a particular software or operating system. (2) In SQL, a set of words reserved for use in SQL statements; you cannot use a reserved word as the name of a database object.
roles
Named groups of related privileges that are granted to users or other roles.
rollback
To discard pending changes made to the data in the current transaction using the SQL ROLLBACK command. You can roll back a portion of a transaction by identifying a savepoint.
row
(1) Synonym for record; one row of data in a database table, having values for one or more columns. Also called tuple. (2) One set of field values in the output of a query. See also column.

S

security level
The combination of a hierarchical classification and a set of non-hierarchical compartments that represent the sensitivity of information.
select
To fetch rows from one or more database tables using a query (the SQL statement SELECT).
SELECT list
The list of items that follow the keyword SELECT in a query. These items may include column names, SQL functions, constants, pseudo-columns, calculations on columns, and aliases. The number of columns in the result of the query will match the number of items in the SELECT list.
SELECT statement
A SQL statement that specifies which rows and columns to fetch from one or more tables or views. See also SQL statement.
Server
Oracle software that handles the functions required for concurrent, shared data access to an Oracle database. The server portion receives and processes SQL and PL/SQL statements originating from client applications. The computer that manages the server portion must be optimized for its duties.
session
The time after a username connects to an Oracle database and before disconnecting, and the events that happen in that time.
SET command variable
See system variable.
spooling
Sending or saving output to a disk storage area. Often used in order to print or transfer files. The SQL*Plus SPOOL command controls spooling.
SQL (Structured Query Language)
The internationally accepted standard for relational systems, covering not only query but also data definition, manipulation, security and some aspects of referential integrity. See also Data Manipulation (DML) language, Data Definition (DDL) language, and Data Control (DCL) language.
SQL buffer
The default buffer containing your most recently entered SQL command or PL/SQL block. SQL*Plus commands are not stored in the SQL buffer.
SQL command
See SQL statement.
SQL script
A file containing SQL statements that you can run in SQL*Plus to perform database administration quickly and easily.
SQL statement
A complete command or statement written in the SQL language. Synonymous with statement (SQL).
SQL*Forms
A non-procedural tool for creating, maintaining, and running full-screen, interactive applications (called "forms") in order to see and change data in an Oracle database. A fourth-generation language for creating interactive screens for use in block-mode, character-mode or bit mapped environments. It has a define time and a runtime component.
SQL*Loader
An Oracle tool used to load data from operating system files into Oracle database tables.
SQL*Net
An Oracle product that works with Oracle Server and enables two or more computers that run the Oracle Server to exchange data through a third-party network. SQL*Net supports distributed processing and distributed database capability. SQL*Net is an "open system" because it is independent of the communications protocol, and users can interface SQL*Net to many network environments.
SQL*Plus
An interactive SQL-based language for data manipulation, data definition and the definition of access rights for an Oracle database. Often used as an end-user reporting tool.
statement (SQL)
A SQL statement, and analogous to a complete sentence, as opposed to a phrase. Portions of SQL statements or commands are called expressions, predicates, or clauses. See also SQL statement.
string
Any sequence of words or characters on a line.
substitution variable
In SQL*Plus, a variable name or numeral preceded by one or two ampersands (&). Substitution variables are used in a command file to represent values to be provided when the command file is run.
subtotal
In a report, a total of values in a number column, taken over a group of rows that have the same value in a break field. See also summary.
summary
Summaries, or summary columns, are used to compute subtotals, grand totals, running totals, and other summarizations of the data in a report.
summary line
A line in a report containing totals, averages, maximums, or other computed values. You create summary lines through the BREAK and COMPUTE commands.
syntax
The orderly system by which commands, qualifiers, and parameters are combined to form valid command strings.
system administrator
A person responsible for operation and maintenance of the operating system of a computer.
system editor
The text editor provided by the operating system.
SYSTEM username
One of two standard DBA usernames automatically created with each database (the other is SYS). The Oracle user SYSTEM is created with the password MANAGER. The SYSTEM username is the preferred username for DBAs to use when performing database maintenance.
system variable
A variable that indicates status or environment, which is given a default value by Oracle or SQL*Plus. Examples are LINESIZE and PAGESIZE. Use the SQL*Plus commands SHOW and SET to see and alter system variables.

T

table
The basic unit of storage in a relational database management system. A table represents entities and relationships, and consists of one or more units of information (rows), each of which contains the same kinds of values (columns). Each column is given a column name, a datatype (such as CHAR, VARCHAR2, DATE, or NUMBER), and a width (the width may be predetermined by the datatype, as in DATE). Once a table is created, valid rows of data can be inserted into it. Table information can then be queried, deleted, or updated. To enforce defined business rules on a table's data, integrity constraints and triggers can also be defined for a table.
table alias
A temporary substitute name for a table, defined in a query and only good during that query. If used, an alias is set in the FROM clause of a SELECT statement and may appear in the SELECT list. See also alias.
text editor
A program run under your host computer's operating system that you use to create and edit host system files and SQL*Plus command files containing SQL commands, SQL*Plus commands, and/or PL/SQL blocks.
timer
An internal storage area created by the TIMING command.
title
One or more lines that appears at the top or bottom of each report page. You establish and format titles through the TTITLE and BTITLE commands.
transaction
A logical unit of work that comprises one or more SQL statements executed by a single user. According to the ANSI/ISO SQL standard, with which Oracle is compatible, a transaction begins with the user's first executable SQL statement. A transaction ends when it is explicitly committed or rolled back by the user.
truncate
To discard or lose one or more characters from the beginning or end of a value, whether intentionally or unintentionally.
Trusted Oracle7
Oracle Corporation's multi-level secure database management system product. It is designed to provide the high level of secure data management capabilities required by organizations processing sensitive or classified information. Trusted Oracle7 is compatible with Oracle base products and applications, and supports all of the functionality of standard Oracle7. In addition, Trusted Oracle7 enforces mandatory access control, including data labeling, across a wide range of multi-level secure operating system environments.
type
A column contains information in one of four types: character, date, number or long. The operations users can perform on the contents of a column depend on the type of information it contains. See also format.

U

USERID
A command line argument that allows you to specify your Oracle username and password with an optional SQL*Net address.
username
The name by which a user is known to the Oracle server and to other users. Every username is associated with a private password, and both must be entered to connect to an Oracle database. See also account.
user variable
A variable defined and set by you explicitly with the DEFINE command or implicitly with an argument to the START command.

V

VARCHAR
An Oracle Corporation datatype. Specifically, this datatype functions identically to the Oracle7 VARCHAR2 datatype (see definition below). However, Oracle Corporation recommends that you use VARCHAR2 instead of VARCHAR because Oracle Corporation may change the functionality of VARCHAR in the future.
VARCHAR2
An Oracle Corporation datatype. Specifically, it is a variable-length, alpha-numeric string with a maximum length of 2000 characters. If data entered for a column of type VARCHAR2 is less than 2000 no spaces will be padded; the data is stored with a length as entered. If data entered is more than 2000, an error occurs. (Note: This datatype is identical to the Oracle Version 6 CHAR datatype, except that its maximum length is 2000 instead of 255.)
variable
A named object that holds a single value. SQL*Plus uses bind substitution, system, and user variables.

W

width
The width of a column, parameter, or layout object. Width is measured in characters; a space is a character.
wrapping
A reporting or output feature in which a portion of text is moved to a new line when the entire text does not fit on one line.



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