The termination of a task, job, or subsystem because of an error condition that recovery facilities cannot resolve during execution.

(1) A system failure or operator action that causes a job to end unsuccessfully.

(2) In DB2, exits that are not under program control, such as a trap or segv.

The full path name of an object. Absolute path names begin at the highest level, or "root" directory (which is identified by the forward slash (/) or back slash (\) character).

(1) The method that is selected by the optimizer for retrieving data from a specific table. For example, an access path can involve the use of an index, a sequential scan, or a combination of the two. (2) The path that is used to locate data that is specified in SQL statements. An access path can be indexed or sequential.

The set of access paths that are selected by the optimizer to evaluate a particular SQL statement. The access plan specifies the order of operations to resolve the execution plan, the implementation methods (such as JOIN), and the access path for each table referenced in the statement.

The primary and secondary log files that are currently needed for recovery and rollback. Contrast with archive log.

A level of authority that gives a user privileges over a set of objects. For example, DBADM authority gives privileges over all objects in a database, and SYSADM authority gives privileges over all objects in a system.

See Tivoli Storage Manager.

An extension to SNA that features distributed network control, dynamic definition of network resources, and automated resource registration and directory lookup.

A collection of interconnected network nodes and their client end nodes.

The general facility that characterizes the LU 6.2 architecture and its various implementations in products.

A separate process or thread that carries out all DB2 requests that are made by a particular client application.

Synonym for column function.

An action, such as a beep or warning, that is generated when a performance variable exceeds or falls below its warning or alarm threshold.

An alternative name used to identify a table, view, database, or nickname.

A cursor that is defined for stored procedure result sets by using the SQL statement ALLOCATE CURSOR.

(1) A cursor that cannot be determined to be updatable or read-only from its definition or context.
(2) A database cursor that is not defined with the FOR FETCH ONLY clause or the FOR UPDATE OF clause, is not defined on a read-only result table, is not the target of a WHERE CURRENT clause on an SQL UPDATE or DELETE statement, and is in a plan or package that contains either PREPARE or EXECUTE IMMEDIATE SQL statements.

organization consisting of producers, consumers, and general
interest groups, that establishes the procedures by which
accredited organizations create and maintain voluntary industry
standards in the United States.

American National Standards Institute.

See application programming interface.

See advanced program-to-program communication.

A program or set of programs that performs a task; for example, a payroll application.

A string that uniquely identifies an application across networks. An ID is generated at the time that the application connects to the database. This ID is known on both the client and the server and can be used to correlate the two parts of the application.

The unit to which resources and locks are allocated. An application process involves the running of one or more programs.

(1) A functional interface supplied by the operating system or by a separately orderable licensed program. An API allows an application program that is written in a high-level language to use specific data or functions of the operating system or the licensed programs.
(2) In DB2, a function within the interface, for example, the get error message API.

A facility that accepts a database request from an application process and passes it to an application server.

The local or remote database manager to which the application process is connected.

In DB2 replication, a program that is used to refresh or update a target table, depending on the applicable source-to-target rules. Contrast with Capture program and Capture trigger.

See Advanced Peer-to-Peer Networking

The set of log files that are closed and are no longer needed for normal processing. These files are retained for use in roll-forward recovery. Contrast with active log.

A value passed to or returned from a function or procedure at run time.

Without regular time relationship; unexpected and unpredictable with respect to the processing of program instructions. Contrast with synchronous.

In DB2, to remotely access objects at the instance level.

In SQL database design, a characteristic of an entity. For example, the phone number of an employee is one of that employee's attributes.

See administrative authority.

A character string in a statement that designates a set of privileges. It is used by the database manager for authorization checking and as an implicit qualifier for the names of objects such as tables, views, and indexes.

To automatically commit the current unit of work after each SQL statement.

(1) A feature that automatically rebinds an invalidated package without requiring a bind command to be entered manually or a bind file to be present.
(2) In DB2 UDB a process by which SQL statements are bound automatically (without a user issuing a BIND command) when an application process begins execution and the bound application plan or package it requires is not valid. See also bind.

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A sequence of bytes with a size ranging from 0 bytes to 2 gigabytes. This string does not have an associated code page and character set. Image, audio, and video objects are stored in BLOBs. Compare to character large object (CLOB).

In SQL, the process by which the output from the SQL precompiler is converted to a usable structure called an access plan. During this process, access paths to the data are selected and some authorization checking is performed.

A file produced by the precompiler when the bind command or API is used with the BINDFILE option. This file includes information about all SQL statements in the application program.

Data with character type CHAR or VARCHAR that is not associated with a coded character set and therefore is never converted.

See binary large object.

A string of data elements recorded or transmitted as a unit.

blocking

An option that is specified when binding an application. It allows caching of multiple rows of information by the communications subsystem so that each FETCH statement does not require the transmission of one row for each request across the network. Contrast with data blocking.

Main storage that is reserved to satisfy the buffering requirements for one or more table spaces.

An SQL function that is provided by DB2 and appears in the SYSIBM schema. Contrast with user-defined function.

byte reversal

A technique in which numeric data is stored with the least significant byte first

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C

A buffer that contains frequently accessed instructions and data; it is used to reduce access time.

The process of storing frequently used results from a request to the Web server locally for quick retrieval, until it is time to refresh the information.

A callable API for database access, which is an alternative to an embedded SQL API. In contrast to embedded SQL, the CLI does not require precompiling or binding by the user, but instead provides a standard set of functions to process SQL statements and related services at run time.

Capture program

In DB2 replication, a program that reads database log or journal records to capture data about changes made to DB2 source tables. Contrast with Apply program and Capture trigger.

In DB2 replication, a mechanism that captures delete, update, and insert operations performed on non-IBM source tables. Contrast with Capture program and Apply program.

cardinality

The number of rows in a database table

The way in which DB2 UDB enforces referential constraints when it deletes all descendent rows of a deleted parent row.

An expression that allows another expression to be selected based on the evaluation of one or more conditions.

A function used to convert instances of a data type (origin) into instances of a different data type (target). In general, cast functions have the name of the target data type. They have a single argument whose type is the origin data type; their return type is the target data type.

A set of tables and views maintained by the database manager. These tables and views contain information about the database, such as descriptions of tables, views, and indexes.

catalog table

Any table in the DB2 UDB catalog.

character large object (CLOB)

A sequence of characters (single-byte, multibyte, or both) up to 2 gigabytes. A CLOB can be used to store large text objects. Also called character large object string. Compare to binary large object (BLOB).

character string

A sequence of bytes or characters.

The characters used to enclose character strings in delimited ASCII files that are imported or exported. See delimiter.

In SQL, an extension to the SQL CREATE TABLE and SQL ALTER TABLE statements that specifies a table check constraint.

A restricted form of search condition used in check constraints.

A constraint that specifies a check condition that is not false for each row of the table on which the constraint is defined.

A state into which a table can be put where only limited activity is allowed on the table and constraints are not checked when the table is updated.

A database log in which records are overwritten if they are no longer needed by an active database. Consequently, if a failure occurs, lost data cannot be restored during forward recovery. Contrast with recoverable log.

See call level interface

(1) Any program (or workstation that it is running on) that communicates with and accesses a database server.
(2) See requester.

CLOB

See character large object

CLP

See Command Line Processor.

Statistics describing the most frequent values of some column or the quantile values. These values are used in the optimizer to help determine the best access plan.

(1) An operation used in queries that applies to the values from several rows. Column functions include SUM, AVG, MIN, MAX, COUNT, STDDEV, and VARIANCE. Synonym for aggregate function.
(2) An SQL operation that derives its result from a collection of values across one or more rows. Contrast with scalar function.

A DB2 operator command. A command is distinct from an SQL statement.

A character-based interface for entering SQL statements and database manager commands.

commit

The operation that ends a unit of work by releasing locks so that the database changes made by that unit of work can be perceived by other processes. This operation makes the data changes permanent.

 

commit point

A point in time when data is considered to be consistent. Synonym for point of consistency.

Common Programming Interface Communications (CPI-C)

An API for applications that require program-to-program communication, using SNA LU 6.2 to create a set of interprogram services.

common table expression

An expression that defines a result table with a name (qualified SQL identifier) that can be specified as a table name in any FROM clause in the fullselect that follows the WITH clause

An infix operator used in comparison expressions. Comparison operators are ¬< (not less than), <= (less than or equal to), ¬= (not equal to), = (equal to), >= (greater than or equal to), > (greater than), and ¬> (not greater than).

An ordered set of key columns of the same table.

A block of SQL statements that are executed in a single call to the application server.

concurrency

The shared use of resources by multiple interactive users or application processes at the same time.

connect

In DB2, to access objects at the database level.

connection

(1) An association between an application process and an application server.
(2) In data communications, an association established between functional units for conveying information.
(3) In SNA, the existence of a communication path between two partner LUs that allows information to be exchanged.

Within the CLI, the data object that contains information associated with a connection. This information includes general status information, transaction status, and diagnostic information.

A timestamp that is used to generate the version identifier for an application.

A language element that specifies an unchanging value. Constants are classified as string constants or numeric constants. Contrast with variable.

A rule that limits the values that can be inserted, deleted, or updated in a table. See check constraint, referential constraint, and unique constraint.

See table space container.

In the database manager, a situation in which a transaction attempts to lock a row or table that is already locked.

Control Center

A graphical interface that shows database objects (such as databases and tables) and their relationship to each other. From the Control Center, you can perform the tasks provided by the DBA Utility, Visual Explain, and Performance Monitor tools.

The authority to completely control an object. This includes the authority to access, drop, or alter an object, and the authority to extend or revoke privileges on the object to other users.

Coordinated Universal Time (UTC)

Synonym for Greenwich Mean Time.

The agent that is started when a request is received by the database manager from an application. It remains associated with the application during the life of the application. This agent coordinates subagents that work for the application. See also subagent.

correlated columns

In SQL, a relationship between the value of one column and the value of another column.

correlated reference

A reference to a column of a table that is outside a subquery.

A subquery that contains a correlated reference to a column of a table that is outside the subquery.

An identifier designating a table or view within a single SQL statement. It can be defined in any FROM clause or in the first clause of an UPDATE or DELETE statement.

When accessing the database, the country code of the application is used to determine the date and time presentation (display and print) formats. It is also used with the code page to determine the default collating sequence for the database.

See Common Programming Interface Communications.

The process of recovering from an immediate failure.

See cursor stability.

current function path

An ordered list of schema names used in the resolution of unqualified references to functions and data types. In dynamic SQL, the current function path is found in the CURRENT FUNCTION PATH special register. In static SQL, it is defined in the FUNCPATH option for PREP and BIND commands.

current working directory

The default directory of a process from which all relative path names are resolved.

cursor

A named control structure used by an application program to point to a specific row within some ordered set of rows. The cursor is used to retrieve rows from a set.

cursor stability (CS)

An isolation level that locks any row accessed by a transaction of an application while the cursor is positioned on the row. The lock remains in effect until the next row is fetched or the transaction is terminated. If any data is changed in a row, the lock is held until the change is committed to the database.

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Database Application Remote Interface. Obsolete term for stored procedure.

A memory area used by a program to hold information.

A person who is responsible for the design, development, operation, safeguarding, maintenance, and use of a database.

Obsolete term for stored procedure.

A workstation used to access a database that is on a database server.

A directory that contains entries for remote databases and the corresponding application requester used to access them.

A directory that contains database access information for all databases to which a client can connect.

The part of the database manager providing the base functions and configuration files needed to use the database.

A set of primary and secondary log files consisting of log records that record all changes to a database. The database log is used to roll back changes for units of work that are not committed and to recover a database to a consistent state.

A table space whose space is managed by the database. Contrast with system-managed space (SMS) table space.

Synonym for database manager.

A computer program that manages data by providing the services of centralized control, data independence, and complex physical structures for efficient access, integrity, recovery, concurrency control, privacy, and security.

database manager instance

A logical database manager environment similar to an image of the actual database manager environment. You can have several instances of the database manager product on the same workstation. You can use these instances to separate the development environment from the production environment, tune the database manager to a particular environment, and protect sensitive information from a particular group of people.

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

A functional unit that provides database services for databases.

database system monitor

A collection of programming APIs that monitor performance and status information about the database manager, databases, and applications using the database manager and DB2 Connect.

data definition language (DDL)

A language for describing data and its relationships in a database. Synonym for data description language.

Synonym for data definition language.

A separately available product that provides client applications integrated access to distributed data and provides a single database image of a heterogeneous environment. With DataJoiner, a client application can join data (using a single SQL statement) that is distributed across multiple database management systems or update a single remote data source as if the data were local.

A DB2 data type that enables logical references from the database to a file stored outside the database.

A subset of SQL statements used to manipulate data.

A subset of a data warehouse that contains data tailored for the specific needs of a department or team. A datamart can be a subset of a warehouse for your entire organization, such as data contained in OLAP tools.

In SQL, an attribute of columns, literals, host variables, special registers, and the results of functions and expressions.

date

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

A DECIMAL(8,0) value that represents a number of years, months, and days.

datetime value

A value of the data type DATE, TIME, or TIMESTAMP.

See database administrator.

See double-byte character large object.

See double-byte character set.

DBMS

Database management system. See database manager.

A logical connection between an application and an agent process or thread owned by a DB2 instance.

DB2 Call Level Interface. An alternative SQL interface for the DB2 family of products that takes full advantage of DB2 capability.

An instruction to DB2 allowing a user to start or stop DB2 UDB, to display information on current users, to display information on the status of databases, and so on.

A product that provides the function necessary (DRDA application requester support) for client applications to read and update data stored in DRDA application servers.

DB2 extender

A program that you can use to store and retrieve data types beyond the traditional numeric and character data, such as image, audio, and video data, and complex documents.

DB2 SDK

See DB2 Application Development Client.

DB2 Application Development Client (DB2 SDK)

A collection of tools that help developers create database applications.

An optional, user-written executable program that the database manager invokes to move or retrieve archive log files.

DCE

See Distributed Computing Environment.

DCE ticket

A transparent application mechanism that transmits the identity of an initiating principal to its target. A simple ticket contains the principal's identity, a session key, a timestamp, and other information, which is sealed using the target's secret key.

DCLGEN

See declarations generator.

See data definition language.

A condition under which a transaction cannot proceed because it is dependent on exclusive resources that are locked by some other transaction, which in turn is dependent on exclusive resources in use by the original transaction.

deadlock detector

A process within the database manager that monitors the states of the locks to determine if a deadlock condition exists. When a deadlock condition is detected, the detector stops one of the transactions involved in the deadlock. This transaction is rolled back and the other transactions proceed.

declarations generator (DCLGEN)

A subcomponent of DB2 UDB that generates SQL table declarations and COBOL, C, or Java data structure declarations that conform to the table. The declarations are generated from DB2 UDB system catalog information.

deferred embedded SQL

SQL statements that are neither fully static nor fully dynamic. Like static statements, they are embedded within an application, but like dynamic statements, they are prepared during the execution of the application.

degree of parallelism

The number of concurrently executed operations that are initiated to process a query.

delete-connected

In SQL, a table that is a dependent of table P or a dependent of a table to which delete operations from table P cascade.

delete rule

A rule associated with a referential constraint that either restricts the deletion of a parent row or specifies the effect of such a deletion on the dependent rows.

delete trigger

A trigger that is defined with the triggering SQL operation DELETE.

delimited identifier

A sequence of characters enclosed within double quotation marks. The sequence must consist of a letter followed by zero or more characters, each of which is a letter, digit, or the underscore character.

delimiter

A character or flag that groups or separates items of data.

delimiter token

A string constant, a delimited identifier, an operator symbol, or any of the special characters shown in syntax diagrams.

In SQL, an object (row, table, or table space) that has at least one parent. See parent row, parent table, parent table space.

A row that contains a foreign key that matches the value of a parent key in the parent row. The foreign key value represents a reference from the dependent row to the parent row.

A table that is a dependent in at least one referential constraint.

descendent

An object that is a dependent of an object or is the dependent of a descendent of an object.

A row that is dependent on another row or a row that is a descendent of a dependent row.

descendent table

A table that is a dependent of another table or a descendent of a dependent table

See not-variant function.

device name

A name reserved by the system, or a device driver that refers to a specific device.

distinct type

A user-defined data type that is internally represented as an existing type (its source type), but is considered to be a separate and incompatible type for semantic purposes.

Distributed Computing Environment (DCE)

A set of services and tools that support the creation, use, and maintenance of distributed applications in a heterogeneous computing environment. DCE is independent of the operating system and network; it provides interoperability and portability across heterogeneous platforms.

Distributed Relational Database Architecture (DRDA)

The architecture that defines formats and protocols for providing transparent access to remote data. DRDA defines two types of functions, the application requester function and the application server function.

distributed request

In a federated database system, an SQL query directed to two or more data sources.

distributed unit of work (DUOW)

A unit of work that allows SQL statements to be submitted to multiple relational database management systems, but no more than one system per SQL statement.

See data manipulation language.

DMS table space

See database-managed space table space.

A sequence of double-byte characters, where the size can be up to 2 gigabytes. A data type that can be used to store large double-byte text objects. Also called double-byte character large object string. Such a string always has an associated code page.

double-byte character set (DBCS)

A set of characters in which each character is represented by two bytes.

double-precision floating point number

In SQL, a 64-bit approximate representation of a real number.

DRDA

See Distributed Relational Database Architecture.

DRDA access

In DB2 UDB for OS/390, a method of accessing distributed data by which you can connect to another location, using an SQL statement, to execute packages that were previously bound at that location. The SQL CONNECT or three-part name statement is used to identify application servers, and SQL statements are executed using packages that were previously bound at those servers. Contrast with private protocol access.

See distributed unit of work.

duration

In SQL, a number that represents an interval of time. See date duration, labeled duration, and time duration.

dynamic bind

A process by which SQL statements are bound as they are entered. See also bind.

dynamic SQL

SQL statements that are prepared and run within a running program. In dynamic SQL, the SQL source is contained in host language variables rather than being coded into the program. The SQL statement might change several times while the program is running.

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Extended binary-coded decimal interchange code. A coded character set of 256 8-bit characters.

embedded SQL

SQL statements coded within an application program. See static SQL.

encoding scheme

A set of rules to represent character data.

equijoin

A join in which the predicate contains an equals operator, for example, T1.C1 = T2.C2.

event monitor

A database object for monitoring and collecting data on database activities over a period of time.

A table that holds rows that violate referential constraints or table check constraints that the CHECK DATA utility finds.

exclusive lock

A lock that prevents concurrently executing application processes from accessing database data.

executable statement

An SQL statement that can be embedded in an application program, dynamically prepared and executed, or issued interactively.

explain

To capture detailed information about the access plan that was chosen by the SQL compiler to resolve an SQL statement. The information describes the decision criteria used to choose the access plan.

explainable statement

An SQL statement for which the explain operation can be performed. Explainable statements are SELECT, UPDATE, INSERT, DELETE, and VALUES.

explained statement

An SQL statement for which an explain operation was performed.

explained statistics

Statistics for a database object that was referenced in an SQL statement at the time that the statement was explained.

explain snapshot

A capture of the current internal representation of an SQL query and related information. This information is required by the Visual Explain tool.

A privilege that has a name and is held as the result of SQL GRANT and REVOKE statements, for example, the SELECT privilege. Contrast with implicit privilege.

To copy data from database manager tables to a file using formats such as PC/IXF, DEL, WSF, or ASC. Contrast with import.

exposed name

A correlation name, a table, or a view name specified in a FROM clause for which a correlation name is not specified.

expression

An SQL operand or a collection of operators and operands that yields a single value.

Extended UNIX Code (EUC)

A protocol that can support sets of characters from 1 to 4 bytes in length. EUC is a means of specifying a collection of code pages rather than actually being a code page encoding scheme itself. This is the UNIX alternative to the PC double-byte (DBCS) code page encoding schemes.

extent

An allocation of space, within a container of a table space, to a single database object. This allocation consists of multiple pages.

extent map

A metadata structure stored within a table space that records the allocation of extents to each object in the table space.

external function

A function for which the body is written in a programming language that takes scalar argument values and produces a scalar result for each invocation. Contrast with sourced function and built-in function.

external routine

A user-defined function or stored procedure that is based on code that is written in an external programming language.

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A group of functions that provide internodal communication support.

federated database system

(1) A DB2 server and multiple data sources that the server sends queries to. In a federated database system, a client application can join data that is distributed across multiple database management systems using a single SQL statement and view the data as if it were local.
(2) A distributed computing system that consists of:
A DB2 server, called a federated server.
Multiple data sources to which the federated server sends queries.

Each data source consists of an instance of a relational database management system plus the database or databases that the instance supports.

The data sources are semi-autonomous. For example, the federated server can send queries to Oracle data sources at the same time that Oracle applications are accessing these data sources.

Pertaining to a type of user-defined function or stored procedure that is defined to protect the DBMS from modifications by the function. The DBMS is isolated from the function or stored procedure by a barrier. Contrast with not-fenced.

file reference variable

A host variable that is used to indicate that data resides in a file on the client rather than in a client memory buffer.

filter factor

A number between zero and one that estimates the proportion of rows in a table for which a predicate is true.

first failure service log

A file (db2diag.log) that contains diagnostic messages, diagnostic data, alert information, and related dump information. This file is used by database administrators.

fixed-length string

A character or graphic string whose length is specified and cannot be changed. Contrast with varying-length string.

forward recovery

A process used to roll forward a database or table space. It allows a restored database or table space to be rebuilt to a specified point in time by applying the changes recorded in the database log.

The total amount of unused space in a page. The space that is not used to store records or control information is free space.

full outer join

The result of an SQL join operation that includes the matched rows of both tables that are being joined and preserves the unmatched rows of both tables. See join.

A subselect, a values-clause, or a number of both that are combined by set operators.

A mapping, embodied as a program (the function body), that can be invoked by using zero or more input values (arguments) to a single value (the result).

The piece of code that implements a function.

The use of a function together with any argument values being passed to the function body. The function is invoked by its name.

function path

An ordered list of schema names that restricts the search scope for unqualified function invocations and provides a final arbiter for the function selection process.

function resolution

The process, internal to the DBMS, for which a particular function instance is selected for invocation. The function name, the data types of the arguments, and the function path are used to make the selection. Synonym for function selection.

function selection

See function resolution.

function signature

The logical concatenation of a fully qualified function name with the data types of all of its parameters. Each function in a schema must have a unique signature.

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A unit of work in a distributed transaction processing environment in which multiple resource managers are required.

governor

See resource limit facility.

grant

To give a privilege or authority to an authorization ID.

graphic character

A DBCS character.

graphic string

A sequence of DBCS characters.

group

(1) A logical organization of users that have IDs according to activity or resource access authority.
(2) In Satellite Edition, a collection of satellites that share characteristics such as database configuration and the application that runs on the satellite.

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(1) A variable that represents an internal structure within a software system.
(2) A character string that is created by an extender that is used to represent an image, audio, or video object in a table. A handle is stored for an object in a user table and in administrative support tables. In this way, an extender can link the handle that is stored in a user table with information about the object that is stored in the administrative support tables.

host

In TCP/IP, any system that has at least one Internet address associated with it.

host computer

(1) In a computer network, a computer that provides services such as computation, database access, and network control functions.
(2) The primary or controlling computer in a multiple computer installation.

host identifier

A name declared in the host program.

host language

Any programming language in which you can embed SQL statements.

host program

A program written in a host language that contains embedded SQL statements.

host structure

In an application program, a structure that is referred to by embedded SQL statements.

host variable

In an application host program, a variable that is referred to by embedded SQL statements. Host variables are programming variables in the application program and are the primary mechanism for transmitting data between tables in the database and application program work areas.

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A privilege that accompanies the ownership of an object, such as the privilege to drop a synonym one owns or the holding of an authority, such as the privilege of SYSADM authority to terminate any utility job.

import

To copy data from an external file, using formats such as PC/IXF, DEL, WSF or ASC, into database manager tables. Contrast with export.

import utility

Transactional utility that inserts user-supplied record data into a table. Contrast with load utility

A process by which SQL statements are bound during the execution of an application process, because they could not be bound during the bind process, and VALIDATE(RUN) was specified. See also bind.

index

A set of pointers that are logically ordered by the values of a key. Indexes provide quick access to data and can enforce uniqueness on the rows in the table.

index key

The set of columns in a table used to determine the order of index entries.

index sargable predicates

SQL predicates that are applied to index entries in index leaf pages to reduce the number of index entries that qualify the SQL request. They help reduce the number of data rows accessed.

indicator variable

A variable used to represent the null value in an application program. If the value for the selected column is null, a negative value is placed in the indicator variable

A transaction in which one phase of a two-phase commit completes successfully but the system fails before a subsequent phase can complete.

The first fullselect in a recursive common table expression that gets the direct children of the initial value from the source table.

inner join

A join method in which a column that is not common to all of the tables being joined is dropped from the resultant table. Contrast with outer join.

A trigger that depends on an object that has been dropped or made inoperative or on a privilege that has been revoked.

A view that is no longer usable because one of the following situations occurs:
SELECT privilege on a table or view that the view is dependent on is revoked from the definer of the view.
An object on which the view definition is dependent was dropped (or possibly made inoperative in the case of another view).

insert rule

A condition enforced by the database manager that must be met before a row can be inserted into a table.

insert trigger

A trigger that is defined with the triggering SQL operation INSERT.

instance

See database manager instance.

A protocol used to route data from its source to its destination in an Internet environment.

Internetwork Packet Exchange (IPX)

A connectionless datagram protocol, used in a NetWare LAN environment, to transfer data to a remote node. IPX makes a best-effort attempt to send data packets, but does not guarantee reliable delivery of the data.

inter-partition parallelism

The ability to perform multiple database operations (such as index creation, database load, and SQL queries) at the same time across multiple partitions of a partitioned database. Contrast with intra-partition parallelism.

Inter-Process Communication (IPC)

A mechanism of an operating system that allows processes to communicate with each other.

intra-partition parallelism

The ability to perform multiple database operations (such as index creation, database load, SQL queries) at the same time within a single database partition. Contrast with inter-partition parallelism

The ability to process parts of a single query at the same time using either intra-partition parallelism, inter-partition parallelism, or both.

A package that becomes invalid when an object that the package depends on is dropped. (The object is of a type other than function, for example, index.) Such a package is implicitly rebound upon invocation. Contrast with inoperative package.

I/O parallelism

See parallel I/O.

IP

See Internet Protocol.

IP address

A 4-byte value that uniquely identifies a TCP/IP host.

IPX

Internetwork Packet Exchange.

ISAPI

Microsoft Internet Server API.

isolation level

An attribute that defines the degree to which an application process is isolated from other concurrently executing application processes.

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A program used to automate certain tasks for running and managing database jobs.

join

An SQL relational operation that allows retrieval of data from two or more tables based on matching column values.

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A column or an ordered collection of columns that are identified in the description of a table, index, or referential constraint.

keyword

(1) One of the predefined words of a computer, command language, or an application.
(2) A name that identifies an option used in an SQL statement.

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A number that represents a duration of years, months, days, hours, minutes, seconds, or microseconds.

large object (LOB)

A sequence of bytes with a length of up to 2 gigabytes. It can be any of three types: BLOB (binary), CLOB (single-byte character or mixed) or DBCLOB (double-byte character).

leaf page

In an index, a page that contains pairs of keys and RIDs and that points to actual data. Contrast with nonleaf page.

left outer join

In DB2 UDB for OS/390, the result of a join operation that includes the matched rows of both tables that are being joined and that preserves the unmatched rows of the first table. See join and right outer join.

length attribute

A value associated with a string that represents the declared fixed length or maximum length of the string.

linkage editor

A computer program for creating load modules from one or more object modules or load modules by resolving cross-references among the modules and, if necessary, adjusting addresses.

link-edit

The action of creating a loadable computer program using a linkage editor.

list prefetch

An access method that takes advantage of prefetching even in queries that do not access data sequentially. This is done by scanning the index and collecting RIDs in advance of accessing any data pages. These RIDs are then sorted, and data is prefetched using this list.

A backup image of data that was loaded at a previous time and can be restored during roll-forward recovery.

load module

A program unit that is suitable for loading into main storage for execution. The output of a linkage editor.

A nontransactional utility that performs block updates of table data. Contrast with import utility.

LOB

See large object.

LOB locator

A mechanism that allows an application program to manipulate a large object (LOB) value in the database system. An LOB locator is a simple token value that represents a single LOB value. An application program retrieves an LOB locator into a host variable and can then apply SQL functions to the associated LOB value using the locator.

LOB table space

A table space that contains all the data for a particular LOB column in the related base table.

local database

A database that is physically located on the workstation in use. Contrast with remote database.

local database directory

A directory where a database physically resides. Databases that are displayed in the local database directory are located on the same node as the system database directory.

locator

See LOB locator.

lock

(1) A means of serializing events or access to data.
(2) A means of preventing uncommitted changes made by one application process from being perceived by another application process and for preventing one application process from updating data that is being accessed by another process.
(3) A means of controlling concurrent events or access to data.

lock duration

The interval over which a DB2 UDB lock is held.

lock escalation

In the database manager, the response that occurs when the number of locks issued for one agent exceeds the limit specified in the database configuration; the limit is defined by the MAXLOCKS configuration parameter. During a lock escalation, locks are freed by converting locks on rows of a table into one lock on a table. This is repeated until the limit is no longer exceeded.

locking

The mechanism used by the database manager to ensure the integrity of data. Locking prevents concurrent users from accessing inconsistent data.

A representation for the type of access that concurrently running programs can have to a resource that a DB2 UDB lock is holding.

lock object

The resource that is controlled by a DB2 UDB lock.

log

(1) A file used to record changes made in a system.
(2) A collection of records that describe the events that occur during DB2 UDB execution and that indicate their sequence. The information thus recorded is used for recovery in the event of a failure during DB2 UDB execution.
(3) See database log.

log head

The oldest written log record in the active log.

logical operator

A keyword that specifies how multiple search conditions are to be evaluated (AND, OR) or if the logical sense of a search condition is to be inverted (NOT).

logical unit of work (LUW)

The processing that a program performs between synchronization points.

log record

A record of an update to a database performed during a unit of work. This record is written after the log tail of the active log.

long string

A varying-length string whose maximum length is greater than 254 bytes.

A table space that can store only long string or large object (LOB) data.

LUW

See logical unit of work.

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(1) The process of putting rows from a view or nested table expression into a work file for additional processing by a query.(2) The placement of an LOB value into contiguous storage. Because LOB values can be very large, DB2 UDB avoids materializing LOB data until doing so becomes absolutely necessary.

MBCS

See multi-byte character set.

migration

(1) The process of moving data from one computer system to another without converting the data.
(2) Installation of a new version or release of a program to replace an earlier version or release.

A string containing a mixture of single-byte and multi-byte characters. Also called mixed data string.

mixed-data string

See mixed-character string.

Database manager parameters manipulated by the user to control the type of information and the quantity of information returned in performance snapshots.

MPP

Massively parallel processing.

A set of characters in which each character is represented by 2 or more bytes. Character sets that use only two bytes are more commonly known as double-byte character sets.

multi-site update

In DB2 UDB, distributed relational database processing in which data is updated in more than one location within a single unit of work.

multitasking

A mode of operation that provides for concurrent performance or interleaved execution of two or more tasks.

MVS

Multiple Virtual Storage, which is part of OS/390.

MVS/ESA

Multiple Virtual Storage/Enterprise Systems Architecture, which is part of OS/390.

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A result table obtained directly or indirectly from one or more other tables through the evaluation of a fullselect that is specified in the FROM clause.

network address

An identifier for a node in a network.

nickname

(1) An identifier that a federated server uses to refer to a data source table or view.
(2) A name that is defined in a DB2 DataJoiner database to represent a physical database object (such as a table or stored procedure) in a non-IBM database.

node

(1) In database partitioning, a synonym for database partition.
(2) In hardware, a uniprocessor or symmetric multiprocessor (SMP) computer that is part of a clustered system or a massively parallel processing (MPP) system. For example, RS/6000 SP is an MPP system that consists of a number of nodes connected by a high-speed network.
(3) In communications, an end point of a communications link, or a junction common to two or more links in a network. Nodes can be processors, communication controllers, cluster controllers, terminals, or workstations. Nodes can vary in routing and other functional capabilities.

node directory

A directory that contains information necessary to establish communications from a client workstation to all applicable database servers.

nodegroup

A named group of one or more database partitions.

nondelimited ASCII (ASC) format

A file format used to import data. Nondelimited ASCII is a sequential ASCII file with row delimiters used for data exchange with any ASCII product.

nonleaf page

In a DB2 UDB index, a page that contains keys and page numbers of other pages in the index (either leaf or nonleaf pages). Nonleaf pages never point to actual data. Contrast with leaf page.

normalization

In databases, the process of restructuring a data model by reducing its relations to their simplest forms.

not-deterministic function

In DB2 UDB, a user-defined function whose result is not solely dependent on the values of the input arguments. Successive invocations with the same argument values can produce a different answer. This type of function is sometimes called a variant function. Contrast with adeterministic function (sometimes called a not-variant function), which always produces the same result for the same input.

A type of user-defined function or stored procedure that is defined to be run in the DBMS process. Contrast with fenced.

not-variant function

A user-defined function whose result is solely dependent on the values of the input arguments. Successive invocations with the same argument values always produce the same results. Contrast with variant function.

NUL

In C language, a single character that denotes the end of the string

A value that indicates the absence of information.

nullable

The condition in which a value for a column, function parameter, or result can have an absence of a value. For example, a field for a person's middle initial does not require a value and is considered nullable.

null value

A parameter position for which no value is specified.

NUL-terminated host variable

A varying-length host variable in which the end of the data is indicated by the presence of a NUL terminator.

NUL terminator

In C language, the value that indicates the end of a string. For character strings, the NUL terminator is X'00'.

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(1) Anything that can be created or manipulated with SQL--for example, tables, views, indexes, or packages.
(2) In object-oriented design or programming, an abstraction consisting of data and operations associated with that data.

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 was made when the database or table space was not being accessed by applications. The Backup Database utility acquires exclusive use of the database until the backup is complete. Contrast with online backup.

offline restore

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

OLAP

See online analytical processing.

online analytical processing (OLAP)

In the OLAP Starter Kit, a multidimensional, multi-user, client server computing environment for users who need to analyze consolidated enterprise data in real time.

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. Contrast with offline backup.

online restore

A restoration of a copy of a database or table space while the database or table space is being accessed by other applications. Contrast with offline restore.

Open Database Connectivity (ODBC)

An API that allows access to database management systems using callable SQL, which does not require the use of an SQL preprocessor. The ODBC architecture allows users to add modules, called database drivers, that link the application to their choice of database management systems at run time. 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.

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.

optimizer

A component of the SQL compiler that chooses an access plan for a data manipulation language statement by modeling the execution cost of many alternative access plans and choosing the one with the minimal estimated cost.

In SQL, a letter followed by zero or more characters, each of which is a letter (a-z and A-Z), a symbol, a number, or the underscore character, used to form a name.

(1) A join method in which a column that is not common to all of the tables being joined becomes part of the resultant table. Contrast with inner join.
(2) In DB2 UDB, 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 that are being joined. See also join.

output file

A database or device file that is opened with the option to allow the writing of records.

overflow record

(1) In DB2, 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.
(2) In the Database Monitor, a record inserted in the event monitor data stream to indicate that records were discarded because the named pipe was full and records were not processed in time. An overflow record indicates how many records were discarded.

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.

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

page

(1) A block of storage within a table or index whose size is 4096 bytes (4 KB).
(2) In DB2 UDB, a unit of storage within a table space (4 KB, 8 KB, 16 KB, or 32 KB).

parallel I/O

The process of reading from or writing to two or more I/O devices at the same time to reduce response time.

parallelism

The ability to perform multiple database operations at the same time (in parallel). See inter-partition parallelism, intra-partition parallelism, and parallel I/O.

parameterized data type

A data type that can be defined with a specific length, scale, or precision. String and decimal data types are parameterized.

parameter marker

A question mark (?) that appears in a statement string of a dynamic SQL statement. The question mark can appear where a host variable might appear if the statement string was a static SQL statement.

parent key

A primary key or unique key that is used in a referential constraint. The values of a parent key determine the valid values of the foreign key in the constraint.

parent row

A row that has at least one dependent row.

parent table

A table that is a parent in at least one referential constraint.

partitioned database

A database with two or more database partitions. Data in user tables can be located in one or more database partitions. When a table is on multiple partitions, some of its rows are stored in one partition and others are stored in other partitions.

Performance Monitor

A tool that lets database administrators use a graphical interface to monitor the performance of a DB2 system for tuning purposes. This tool can be accessed from the Control Center.

performance snapshot

Performance data for a set of database objects that is retrieved from the database manager at a point in time.

performance variable

A statistic derived from performance data obtained from the database manager. The expression for this variable can be user defined.

performance variable profile

A flat file that contains definitions of performance variables. This file can be edited, copied, and shared. Different profiles can be used by the same Performance Monitor so that different calculations can be performed.

phantom row

A table row that can be read by application processes that are executing with any isolation level except repeatable read. When an application process issues the same query multiple times within a single unit of work, additional rows can appear between queries because of the data being inserted and committed by application processes that are running concurrently.

point of consistency

A point in time when all the recoverable data a program accesses is consistent. The point of consistency occurs when updates, inserts, and deletions are either committed to the physical database or rolled back. Synonym for commit point and sync point.

precision

In numeric data types, the total number of binary or decimal digits, excluding the sign.

precompile

To process programs that contain SQL statements before they are compiled. SQL statements are replaced with statements that will be recognized by the host language compiler. The output from a precompile process includes source code that can be submitted to the compiler and used in the bind process.

predicate

An element of a search condition that expresses or implies a comparison operation.

prefetch

To read data ahead of, and in anticipation of, its use.

prepare

(1) To convert an SQL statement from text form to an executable form, by submitting it to the SQL compiler.
(2) In DB2 UDB, the first phase of a two-phase commit process in which all participants are requested to prepare for commit.

In SQL, a named object that is the executable form of an SQL statement that has been processed by the PREPARE statement.

primary key

A unique key that is part of the definition of a table. A primary key is the default parent key of a referential constraint definition.

A set of one or more log files used to record changes to a database. Storage for these files is allocated in advance. Contrast with secondary log.

private protocol access

A method of accessing distributed data by which you can direct a query to another DB2 system. Contrast with DRDA access.

privilege

(1) The right to access a specific database object in a specific way. These rights are controlled by users with SYSADM (system administrator) authority or DBADM (database administrator) authority or by creators of objects. Privileges include rights such as creating, deleting, and selecting data from tables.
(2) In DB2 UDB, the capability of performing a specific function, sometimes on a specific object. See also explicit privilege and implicit privilege.

procedure

See stored procedure.

public authority

The authority for an object granted to all users.

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A predicate that compares a value with a set of values.

query

(1) A request for information from the database based on specific conditions, for example, a request for a list of all customers in a customer table whose balance is greater than $1000.
(2) A component of certain SQL statements that specifies a result table.

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RDB

See relational database.

RDBMS

See relational database management system.

read stability (RS)

An isolation level that locks only the rows that an application retrieves within a transaction. Read stability ensures that any qualifying row that is read during a transaction is not changed by other application processes until the transaction is completed, and that any row changed by another application process is not read until the change is committed by that process. Read stability allows more concurrency than repeatable read, and less than cursor stability.

rebind

To create a package for an application program that was previously bound. For example, if an index is added for a table that is accessed by a program, the package must be rebound for it to take advantage of the new index.

record

The storage representation of a single row of a table or other data.

record identifier (RID)

A number that is used internally by DB2 to uniquely identify a record in a table. The RID contains enough information to address the page in which the record is stored. Compare with row ID.

A database log in which all log records are retained so that, in the event of a failure, lost data can be recovered during forward recovery. Contrast with circular log.

recovery

(1) The act of resetting a system, or data that is stored in a system, to an operable state following damage.
(2) The process of rebuilding databases by restoring a backup and rolling forward the logs associated with it.

recovery log

See database log.

recovery pending

A state of the database or table space. A database or table space is put in recovery pending state when it is restored from a backup. While the database or table space is in this state, its data cannot be accessed.

recursion cycle

The cycle that occurs when a fullselect within a common table expression includes the name of the common table expression in a FROM clause.

recursive common table expression

A common table expression that refers to itself in a FROM clause from the fullselect. Recursive common table expressions are used to write recursive queries.

recursive query

A fullselect that uses a recursive common table expression.

referential constraint

The referential integrity rule that the nonnull values of the foreign key are valid only if they also appear as values of a parent key.

referential integrity

(1) The state of a database in which all values of all foreign keys are valid.
(2) The condition that exists when all intended references from data in one column of a table to data in another column of the same or a different table are valid. Maintaining referential integrity requires that DB2 UDB enforce referential constraints on all LOAD, RECOVER, INSERT, UPDATE, and DELETE operations.

refresh

A process in which all of the data of interest in a user table is copied to the target table, replacing existing data. See also full refresh and differential refresh.

regular table space

A table space that can store any nontemporary data.

A database that can be perceived as a set of tables and manipulated in accordance with the relational model of data.

relational database management system (RDBMS)

In DB2 UDB, a collection of hardware and software that organizes and provides access to a relational database.

remote database

A database that is physically located on a workstation other than the one in use. Contrast with local database.

remote unit of work (RUOW)

A unit of work that allows for the remote preparation and execution of SQL statements.

repeatable read (RR)

An isolation level that locks all the rows in an application that are referenced within a transaction. When a program uses repeatable read protection, rows referenced by the program cannot be changed by other programs until the program ends the current transaction.

replication

The process of maintaining a defined set of data in more than one location. It involves copying designated changes for one location (a source) to another (a target), and synchronizing the data in both locations.

replication administrator

The user responsible for defining replication sources and subscriptions. This user can also run the Capture and Apply programs.

replication source

A database table or view that can accept copy requests and is the source table in a subscription set. See also subscription set.

replication subscription

A specification for copying changed data from replication sources to target tables at a specified time and frequency, with the option of enhancing data. It defines all of the information that is required by the Apply program to copy data.

(1) A word used in a source program to describe an action to be taken by the program or compiler. It must not appear in the program as a user-defined name or a system name.
(2) A word that has been set aside for special use in the SQL standard.

restore

To return a backup copy to the active storage location for use.

restore set

A backup copy of a database or table space plus zero or more log files that, when restored and rolled forward, bring the database or table space back to a consistent state.

result set

The set of rows that a stored procedure returns.

result table

The set of rows produced by the evaluation of a SELECT statement.

revoke

To remove a privilege or authority from an authorization ID

See record identifier.

right outer join

In DB2 UDB, the result of a join operation that includes the matched rows of both tables that are being joined and preserves the unmatched rows of the second join operand. See join.

rollback

The process of restoring data changed by SQL statements to the state at its last commit point. See point of consistency.

The process of updating the data in a restored database by applying changes recorded in the database log. See forward recovery.

root page

In DB2 UDB, the page of an index page set that follows the first index space map page. A root page is the highest level (or the beginning point) of the index.

row

The horizontal component of a table consisting of a sequence of values, one for each column of the table.

ROWID

See row identifier.

row identifier (ROWID)

In DB2 UDB, a value that uniquely identifies a row. This value is stored with the row and does not change.

row lock

In DB2 UDB, a lock on a single row of data.

row trigger

A trigger that is defined with the trigger granularity FOR EACH ROW.

RR

See repeatable read.

RS

See read stability.

RUOW

See remote unit of work.

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A predicate that can be evaluated as a search argument.

An occasionally connected client that has a DB2 server that synchronizes with its group at the satellite control database.

A user interface that provides centralized administrative support for satellites

A DB2 Universal Database system that contains the satellite control database, SATCTLDB.

SBCS

See single-byte character set.

scalar fullselect

A fullselect that returns a single value--one row of data that consists of exactly one column.

scalar function

An SQL operation that produces a single value from another value and is expressed as a function name followed by a list of arguments enclosed in parentheses. Contrast with column function.

The number of digits in the fractional part of a number.

A collection of database objects such as tables, views, indexes, or triggers. A database schema provides a logical classification of database objects.

See Software Developer's Kit.

search condition

A criterion for selecting rows from a table. A search condition consists of one or more predicates

A set of one or more log files used to record changes to a database. Storage for these files is allocated as needed when the primary log is full. Contrast with primary log.

In DB2 UDB, the segment of a plan or package that contains the executable structures for a single SQL statement. For most SQL statements, one section in the plan exists for each SQL statement in the source program. However, for cursor-related statements, the DECLARE, OPEN, FETCH, and CLOSE statements reference the same section because, they each refer to the SELECT statement that is named in the DECLARE CURSOR statement. SQL statements such as COMMIT, ROLLBACK, and some SET statements do not use a section.

self-referencing constraint

In DB2 UDB, a referential constraint that defines a relationship in which a table is a dependent of itself.

self-referencing row

A row that is a parent of itself.

self-referencing subquery

A subselect or fullselect within a DELETE, INSERT, or UPDATE statement that refers to the same table that is the object of the SQL statement.

self-referencing table

A table that is both a parent and a dependent table in the same referential constraint.

sequential prefetch

In DB2 UDB, a mechanism that triggers consecutive asynchronous I/O operations. Pages are fetched before they are required, and several pages are read with a single I/O operation.

server

In a network, a node that provides facilities to other stations, for example, a file server, a printer server, a mail server.

The SQL operators UNION, EXCEPT, and INTERSECT corresponding to the relational operators union, difference, and intersection. A set operator derives a result table by combining two other result tables.

shared lock

A lock that limits concurrently executing application processes to read-only operations on database data. Contrast with exclusive lock.

A special control character (X'0F') that is used in EBCDIC systems to denote that the subsequent bytes represent SBCS characters. Contrast with shift-out character.

shift-out character

A special control character (X'0E') that is used in EBCDIC systems to denote that the subsequent bytes, up to the next shift-in control character, represent DBCS characters. Contrast with shift-in character.

A fixed-length string or a variable-length string whose maximum length is less than or equal to 254 bytes.

A character set in which each character is represented by a one-byte code.

A 32-bit approximate representation of a real number.

SMS table space

See system-managed space table space.

SNA

See Systems Network Architecture.

SNA network

The part of the user application network that conforms to the formats and protocols of Systems Network Architecture (SNA). It enables reliable transfer of data among users and provides protocols for controlling the resources of various network configurations. The SNA network consists of network addressable units (NAUs), gateway function, intermediate session routing function components, and the transport network.

snapshot

See performance snapshot and explain snapshot.

A callable TCP/IP programming interface that is used by TCP/IP network applications to communicate with remote TCP/IP partners.

soft checkpoint

The process of writing some information to the log file header; this information is used to determine the starting point in the log in case a database restart is required.

Software Developer's Kit (SDK)

An application development product that allows applications to be developed on a client workstation to access remote database servers including host relational databases through the DB2 Connect products.

source function

A user-defined function (UDF) that is used to implement one or more other UDFs.

sourced function

In DB2 UDB, a function that is implemented by another built-in or user-defined function that is already known to the database manager. This function can be a scalar function or a column (aggregating) function; it returns a single value from a set of values (for example, MAX or AVG). Contrast with external function and built-in function.

source program

A set of host language statements and SQL statements that is processed by an SQL precompiler.

source table

In DB2 replication, a table that contains the data that is to be copied to a target table. Contrast with target table.

source type

An existing type that is used to internally represent a distinct type.

special register

A storage area that is defined for an application process by the database manager and is used to store information that can be referenced in SQL statements. Examples are USER and CURRENT DATE.

specific function name

The name that uniquely identifies a function to the system.

See Structured Query Language.

In DB2 UDB, the authorization ID that is used for checking dynamic SQL statements in some situations.

SQLCA

See 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 or its requests from the database manager.

SQLDA

See SQL descriptor area.

SQL descriptor area (SQLDA)

(1) A set of variables that is used in the processing of certain SQL statements. The SQLDA is intended for dynamic SQL programs.
(2) A structure that describes input variables, output variables, or the columns of a result table.

See SQL authorization ID.

SQL return code

Either SQLCODE or SQLSTATE.

statement

An instruction in a program or procedure

In CLI, a handle that refers to the data object that contains information about an SQL statement. This includes information such as dynamic arguments, bindings for dynamic arguments and columns, cursor information, result values, and status information. Each statement handle is associated with a connection handle.

static bind

A process by which SQL statements are bound after they are precompiled. All static SQL statements are prepared for execution at the same time. See also bind.

statement trigger

A trigger that is defined with the trigger granularity FOR EACH STATEMENT.

static SQL

SQL statements that are embedded within a program, and are prepared during the program preparation process before the program is executed. After being prepared, a static SQL statement does not change, although values of host variables specified by the statement can change.

(1) A block of procedural constructs and embedded SQL statements that is stored in a database and can be called by name. Stored procedures allow an application program to be run in two parts. One part runs on the client and the other on the server. This allows one call to produce several accesses to the database. Synonym for procedure.
(2) A user-written application program that can be started through the use of the SQL CALL statement.

A tool for creating stored procedures, building stored procedures on local and remote DB2 servers, modifying and rebuilding existing stored procedures, and testing and debugging the execution of installed stored procedures using a graphical interface. This tool is standalone or can be accessed from various integrated development environments.

Stored Procedure Builder project

A file that is created by the Stored Procedure Builder that contains connection information and stored procedure objects that have not been successfully built in the database.

string

In programming languages, the form of data used for storing and manipulating text.

strong typing

A process that guarantees that only user-defined functions and operations that are defined on a distinct type can be applied to that type. For example, you cannot directly compare two currency types, such as Canadian dollars and US dollars. But you can provide a user-defined function to convert one currency to the other and then do the comparison.

A standardized language for defining and manipulating data in a relational database.

subagent

A type of agent that works on subrequests. A single application can make many requests, and each request can be broken into many subrequests. Therefore, there can be multiple subagents working on behalf of the same application. All subagents working for the application are coordinated by the coordinating agent for that application.

subordinate agent

See subagent.

subquery

A SELECT statement within the WHERE or HAVING clause of another SQL statement; a nested SQL statement.

subscription

See subscription set.

subscription process

In DB2 replication, a process in which you define subscription sets and subscription-set members. Contrast with registration process.

subscription set

In DB2 replication, the specification of a group of source tables, target tables, and the control information that governs the replication of changed data. See also subscription-set member.

subscription-set member

In DB2 replication, a member of a subscription set. There is one member for each source-target pair. Each member defines the structure of the target table and which rows and columns will be replicated from the source table.

subselect

That form of a query that does not include an ORDER BY clause, an UPDATE clause, or UNION operators.

substitution character

In SQL, a unique character that is substituted during character conversion for any characters in the source program that do not have a match in the target coding representation.

synchronous

Pertaining to two or more processes that depend upon the occurrences of specific events, such as a common timing signal. Contrast with asynchronous.

See point of consistency.

system administrator

The person at a computer installation who designs, controls, and manages the use of the computer system.

system catalog

See catalog.

system database directory

A directory that contains entries for every database that can be accessed using the database manager. It is created when the first database is created or cataloged on the system.

system-managed space (SMS) table space

A table space whose space is managed by the operating system. This storage model is based on files created under subdirectories, and managed by the file system. Contrast with database managed space (DMS) table space.

Systems Network Architecture (SNA)

The description of the logical structure, formats, protocols, and operational sequences for transmitting information units through the networks and also the operational sequences for controlling the configuration and operation of networks.

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A named data object consisting of a specific number of columns and some unordered rows. See also base table.

table check constraint

A user-defined constraint that specifies the values that specific columns of a base table can contain.

table designator

A column name qualifier that designates a specific object table.

table function

A function that receives a set of arguments and returns a table to the SQL statement that refers to the function. A table function can be referenced only in the FROM clause of a subselect.

table space

An abstraction of a collection of containers into which database objects are stored. A table space provides a level of indirection between a database and the tables stored within the database. A table space:
Has space on media storage devices assigned to it.
Has tables created within it. These tables use space in the containers that belong to the table space. The data, index, long field, and LOB portions of a table can be stored in the same table space, or can be individually broken out into separate table spaces.

A generic term describing an allocation of space to a table space. Depending on the table space type, the container can be a directory, device, or file.

In DB2 replication, the database location of the target table. Normally this is also the location of the Apply program.

target table

In DB2 replication, the table on the target server to which data is copied.

TCP/IP

See Transmission Control Protocol/Internet Protocol.

TCP/IP port

A 2-byte value that identifies an end user or a TCP/IP network application within a TCP/IP host.

temporary table

A table created during the processing of an SQL statement to hold intermediate results. Contrast with result table.

temporary table space

A table space that can store only temporary tables.

territory

A portion of the POSIX locale that is mapped to the country code for internal processing by the database manager.

thread

In some operating systems, the smallest unit of operation to be performed in a process.

An event that occurs when the value of a performance variable exceeds or falls below a user-defined threshold value. The action that occurs as a result of a threshold trigger can be:
Logging inormation in an alert log file.
Displaying information in an alert log window.
Generating an audio alarm.
Issuing a message window.
Invoking a predefined command or program.

time

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

time duration

A DECIMAL(6,0) value that represents a number of hours, minutes, and seconds.

timeron

A unit of measurement used to give a rough relative estimate of the resources, or cost, required by the database server to execute two plans for the same query. The resources calculated in the estimate include weighted processor and I/O costs.

timestamp

A seven-part value that consists of a date and time expressed in years, months, days, hours, minutes, seconds, and microseconds.

A DECIMAL(20,6) value that represents a number of years, months, days, hours, minutes, seconds, and microseconds.

Tivoli Storage Manager (TSM)

A client/server product that provides storage management and data access services in a heterogeneous environment. TSM supports various communication methods, provides administrative facilities to manage the backup and storage of files, and provides facilities for scheduling backup operations.

TM Database

See Transaction Manager Database.

token

The basic syntactic unit of a computing language. A token consists of one or more characters, excluding the blank character and excluding characters within a string constant or delimited identifier.

TP

See transaction program.

transaction

An exchange between a workstation and a program, two workstations, or two programs that accomplish a particular action or result. An example is the entry of a customer's deposit and the update of the customer's balance. Synonym for unit of work.

transaction compensation

A process that restores rows that are affected by a committed transaction that is rejected. When a committed transaction is rejected, the rows are restored to the state that they were in before the transaction was committed.

A function that assigns identifiers to transactions, monitors their progress, and takes responsibility for transaction completion and failure recovery.

Transaction Manager Database (TM Database)

A database that is used to log transactions when a two-phase commit (SYNCPOINT TWOPHASE) is used with DB2 databases. In the event of transaction failure, the TM Database information can be accessed to resynchronize databases involved in the failed transaction.

transition variable

A variable that is valid only in FOR EACH ROW triggers. It allows access to the transition values for the current row. An old transition variable is the value of the row before the modification is applied, and the new transition variable is the value of the row after the modification is applied.

Transmission Control Protocol/Internet Protocol (TCP/IP)

A set of communications protocols that provide peer-to-peer connectivity functions for both local and wide area networks.

trigger

(1) In DB2, an object in a database that is invoked indirectly by the database manager when a particular SQL statement is run.
(2) A set of SQL statements that are stored in a DB2 UDB database and executed when a certain event occurs in a DB2 UDB table.

triggered action

(1) The action that is executed when the trigger event occurs.
(2) In DB2 UDB, the SQL logic that is performed when a trigger is activated. The triggered action consists of an optional triggered action condition and a set of triggered SQL statements that are executed only if the condition evaluates to true.

(1) The search condition that controls the execution of the SQL statements within the triggered action.
(2) In DB2 UDB, an optional part of the triggered action. This Boolean condition appears as a WHEN clause and specifies a condition that DB2 evaluates to determine if the triggered SQL statements should be executed.

triggered SQL statements

In DB2 UDB, the set of SQL statements that is executed when a trigger is activated and its triggered action condition evaluates to true. Triggered SQL statements are also called the trigger body.

trigger event

In a trigger definition, an update operation (INSERT, UPDATE, or DELETE statement) that causes the trigger to be run.

triggering event

In DB2 UDB, the specified operation in a trigger definition that causes the activation of that trigger. The triggering event is comprised of a triggering operation (INSERT, UPDATE, or DELETE) and a triggering table on which the operation is performed.

triggering SQL operation

In DB2 UDB, the SQL operation that causes a trigger to be activated when performed on the triggering table.

triggering table

In DB2 UDB, the table for which a trigger is created. When the defined triggering event occurs on this table, the trigger is activated.

truncation

The process of discarding part of a result from an operation when it exceeds memory or storage capacity.

two-phase commit

A two-step process by which recoverable resources and an external subsystem are committed. During the first step, the database manager subsystems are polled to ensure that they are ready to commit. If all subsystems respond positively, the database manager instructs them to commit.

A parameter marker that is specified along with its target data type. It has the general form: CAST(? AS data-type)

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See user-defined function

UDT

See user-defined type.

A cursor that allows a relational database to determine whether blocking can be used with the answer set. A cursor defined FOR FETCH ONLY or FOR READ ONLY can be used with blocking, whereas a cursor defined FOR UPDATE cannot.

uncommitted read (UR)

An isolation level that allows an application to access uncommitted changes of other transactions. The application does not lock other applications out of the row it is reading, unless the other application attempts to drop or alter the table.

uncoordinated transaction

A transaction that accesses more than one resource, but its commit or rollback is not being coordinated by a transaction manager.

Unicode

An international character encoding scheme that is a subset of the ISO 10646 standard. Each character supported is defined using a unique 2-byte code.

unique constraint

The rule that no two values in a primary key or key of a unique index can be the same. Also referred to as uniqueness constraint.

unique index

An index that ensures that no identical key values are stored in a table.

unique key

A key that is constrained so that no two of its values are equal.

unit of recovery

A recoverable sequence of operations within a single resource manager, such as an instance of DB2 UDB. Contrast with unit of work.

unit of work

A recoverable sequence of operations within an application process. At any time, an application process is a single unit of work, but the life of an application process can involve many units of work as a result of commit or rollback operations. In a DB2 UDB for OS/390 multi-site update operation, a single unit of work can include several units of recovery. Synonym for transaction.

unlock

The act of releasing an object or system resource that was previously locked and returning it to general availability within DB2 UDB.

update rule

A condition enforced by the database manager that must be met before a column can be updated.

update trigger

A trigger that is defined with the triggering SQL operation UPDATE.

UR

See uncommitted read.

user-defined data type (UDT)

See distinct type.

user-defined distinct type

See distinct type.

user-defined function (UDF)

A function that is defined to the database management system and can be referred to in SQL queries. It can be one of the following functions:
An external function, in which the body of the function is written in a programming language whose arguments are scalar values and a scalar result is produced for each invocation.
A sourced function, implemented by another built-in or user-defined function already known to the DBMS. This function can be either a scalar function or column (aggregating) function, and returns a single value from a set of values (for example, MAX or AVG).

user-defined type (UDT)

A data type that is not native to the database manager and was created by a user.

UTC

See Coordinated Universal Time.

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(1) The smallest unit of data manipulated in SQL.
(2) A specific data item at the intersection of a column and a row.

A data element that specifies a value that can be changed.

variant function

A user-defined function whose result is dependent on its input parameter values as well as other factors. Successive invocations with the same parameter values might produce different results. Contrast with not-variant function.

A character, graphic, or binary string whose length is not fixed but can range within set limits. Also referred to as a variable-length string.

view

A logical table that consists of data that is generated by a query. Contrast with base table.

view check option

In DB2 UDB, an option that specifies whether every row that is inserted or updated through a view must conform to the definition of that view. A view check option can be specified with the WITH CASCADED CHECK OPTION, WITH CHECK OPTION, or WITH LOCAL CHECK OPTION clauses of the CREATE VIEW statement.

Visual Explain

A tool that lets database administrators and application programmers use a graphical interface to display and analyze detailed information on the access plan of a given SQL statement. The tasks provided by this tool can be accessed from the Control Center.

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A subject-oriented nonvolatile collection of data used to support strategic decision making. The warehouse is the central point of data integration for business intelligence. It is the source of data for datamarts within an enterprise and delivers a common view of enterprise data.

In a federated database system, the mechanism by which the federated server invokes routines to communicate with, and retrieve data from, a data source. The routines are contained in a library called a wrapper module.

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