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Q.921
- The ITU-T (formerly CCITT)
recommendation that defines the link layer of the DSS1 protocol. Q.921 defines
an HDLC protocol that ensures a reliable connection between the network and
the user. Often used synonymously with LAPD.
-
Q.931
- An ITU recommendation that
defines the network layer protocol for integrated services digital network
(ISDN). This layer carries the ISDN messages that control the establishment
and clearing of calls.
-
Q.932
- The CCITT Recommendation that
defines the generic procedures applicable for the control of supplementary
services at the user-network interface. These procedures expand on the basic
call-control functions defined in Q.931. See also supplementary service.
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QA
- See quality
assurance.
-
Q Apply latency
- In Q replication,
an approximate measurement of the difference between the time that the Q Apply
program gets changed data from the receive queue and the time that the data
is applied to a target table. This is a subset of the end-to-end latency in
a replication scenario. See also latency, Apply latency, Capture latency, Q Capture latency, queue latency, end-to-end latency.
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Q Apply program
- In Q replication,
a program that reads transactions from a receive queue and applies those changes
to one or more target tables or passes the changes to a procedure.
-
Q Apply schema
- In Q replication,
the identifier for a Q Apply program and its control tables.
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Q Apply server
- In Q replication,
a database or subsystem on which the control tables for the Q Apply program
are located and where the Q Apply program runs. It contains one or more sets
of the control tables that store information about target tables and other
replication definitions.
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QBE
- See Query
by Example.
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QBIC
- See Query
by Image Content.
-
Qbuffer
- See queue buffer.
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Q Capture latency
- In Q replication,
an approximate measure of how current a Q Capture program is in reading the
DB2 database recovery log. It is the approximate difference between the time
that source data was changed and the time that the Capture program made the
data available by committing it to WebSphere MQSeries. This is a subset of
the end-to-end latency in a replication scenario. See also latency, Apply latency, Capture latency, Q Apply latency, queue latency, end-to-end latency.
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Q Capture program
- In Q replication
and event publishing, a program that reads the DB2 database recovery log to
capture changes made to DB2 database source tables and transmits the changes
by using one or more WebSphere MQ queues. See also Capture program, Q replication, event publishing.
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Q Capture schema
- In Q replication,
the identifier for a Q Capture program and its control tables.
-
Q Capture server
- In Q replication
and event publishing, a database or subsystem on which the control tables
for the Q Capture program are located and where the Q Capture program runs.
The Q Capture server contains one or more sets of the control tables that
store information about Q subscriptions and XML publications and other replication
or publishing definitions. See also control server.
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Q Capture transaction latency
- In
Q replication, the time between when a Q Capture program reads the commit
statement for a transaction in the DB2 database recovery log and when the
Q Capture program puts the message that contains the transaction on a send
queue.
-
QCMD
- The IBM-supplied control language
processor that interprets and processes CL commands for the system.
-
q_data
- See qualifying data.
-
QGPL
- See general
purpose library.
-
QHST
- A message destination that is
an alternative to the job log.
-
QLLC
- See Qualified
Logical Link Control.
-
QMF
- See Query
Management Facility.
-
QMGR
- See Queue
Manager.
-
QName
- See qualified name.
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Qname
- See queue name.
-
QoS
- See quality
of service.
-
QoS policy
- A set of actions that
a network takes to configure and signal for a particular quality of service
(QoS) service to be provided to a particular traffic classification.
-
Q replication
- A replication solution
that uses WebSphere MQ message queues for high-volume, low-latency replication.
See also high availability disaster recovery, Q Capture program, SQL replication.
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QSAM
- See queued
sequential access method.
-
Qshell Interpreter
- A standard command
interface that is used to run standard commands, such as UNIX-like commands
and Java commands, and then view the output.
-
QSN
- See queue
sequence number.
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QSRV
- The IBM-supplied user profile
for a service representative.
-
Q subscription
- In Q replication,
an object that identifies a mapping between a source table and target table
or procedure and specifies what changes are replicated. See also subscription, XML publication, replication source.
-
Q subscription group
- In Q replication,
the Q subscriptions that are involved in replicating the same logical tables.
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QSYS
- (1) The library shipped with the
system that contains objects, such as authorization lists and device descriptions
created by a user, and the system commands and other system objects required
to run the system. The system identifier is QSYS.
- (2) The IBM-supplied
user profile that owns most IBM-supplied objects.
-
qualified call
- A DL/I call that contains
at least one segment search argument.
-
qualified class name
- Any class name
or class name qualified with one or more :: (scope) operators.
-
qualified data-name
- In COBOL, an
identifier that is composed of a data-name followed by one or more sets of
either of the connectives OF or IN followed by a data-name qualifier.
-
qualified job name
- A job name and
its associated user name and a system-assigned job number. See also job name.
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Qualified Logical Link Control (QLLC)
- An X.25 protocol that allows the transfer of data link control information
between two adjoining SNA nodes that are connected through an X.25 packet-switching
data network. The QLLC provides the qualifier Q bit in X.25 data packets to
identify packets that carry logical link protocol information. See also enhanced logical link control, physical services header.
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qualified name (QName)
- (1) The name of
the library containing the object and the name of the object. See also object name.
- (2) A data name explicitly accompanied
by a specification of the class to which it belongs in a specified classification
system.
- (3) In C++, a name that is used to qualify a nonclass type
name, such as a member, by its class name.
- (4) A data set name consisting
of a string of names separated by periods; for example, TREE.FRUIT.APPLE is
a qualified name.
- (5) A name that conforms to the Namespaces in XML
specification. A QName consists of an optional prefix, or its associated URI,
and a local name. See also expanded QName, in-scope namespace, lexical QName.
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qualified segment search argument
- An segment search argument (SSA) that contains, in addition to the segment
name, one or more qualification statements. A qualified SSA describes the
segment type and occurrence that is to be accessed. See also segment search argument.
-
qualified type name
- A name used to
reduce complex class name syntax by using typedefs to represent qualified
class names.
-
qualifier
- (1) A modifier that makes a
name unique.
- (2) Each component name in a qualified name other than
the right-most name. For example, TREE and FRUIT are qualifiers in TREE.FRUIT.APPLE.
- (3) A value that provides additional information about a class, association,
indication, method, method parameter, instance, property, or reference.
- (4) A simple element that gives another generic compound or simple element
a specific meaning. Qualifiers are used in mapping single or multiple occurrences.
A qualifier can also be used to denote the namespace used to interpret the
second part of the name, usually referred to as the ID.
- (5) When referring
to a QMF object, the part of the name that identifies the owner or the location
of an object. When referring to a TSO data set, any part of the name that
is separated from the rest of the name by periods. For example, 'TCK', 'XYZ',
and 'QUERY' are all qualifiers in the data set name 'TCK.XYZ.QUERY'.
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qualifying data (q_data)
- Unique information
associated through a condition token with a given instance of a condition.
A user-written condition handler uses q_data to identify and react to the
condition.
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quality
- The features and characteristics
of a product or service that satisfy stated or implied user needs.
-
quality assurance (QA)
- The actions
necessary to provide adequate confidence that a product or service satisfies
defined requirements for quality.
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quality of protection
- The level of
data security, determined by a combination of authentication, integrity, and
privacy conditions.
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quality of service (QoS)
- (1) Any operation
that allows traffic priorities to be designated. Through quality of service,
different traffic throughout a network can be classified and administered.
- (2) In OSI, a value that specifies certain performance characteristics
of a service, session, or link. In OSI Communications Subsystem, quality of
service is provided at the network layer.
- (3) For an asynchronous
transfer mode (ATM) virtual channel or a Networking BroadBand Services (NBBS)
network connection, a set of communication characteristics such as end-to-end
delay, jitter, and packet loss ratio.
- (4) A set of communication characteristics
required by an application. QoS defines a specific transmission priority,
level of route reliability, and security level.
- (5) A measure of system
performance and system availability.
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Quality of Service policy
- A policy
that collects performance data for HTTP transactions for one or more Web servers,
including the entire round-trip time of the transaction, the back-end service
time, and the page display time.
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quality risk
- A concern that can diminish
the quality of a software product.
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quantified predicate
- A predicate
that compares a value with a set of values.
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quantile
- A subgroup that is created
when a group is divided into equal, ordered parts.
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quartile analysis
- A type of analysis
that displays the value of the business measures boundaries at the 25th, 50th,
or 75th percentiles of a frequency distribution divided into four parts, each
containing a quarter of the population.
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quasi-reentrant
- Pertaining to CICS
application programs that run under the CICS quasi-reentrant task control
block (QR TCB). See also reenterable.
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query
- (1) A request for information from
a database based on specific conditions: for example, a request for a list
of all customers in a customer table whose balances are greater than $1000.
- (2) A component of certain SQL or XQuery statements that specifies
a result set.
- (3) In interactive systems, an operation at a workstation
that elicits a response from the system.
- (4) In a Tivoli environment,
a combination of statements that are used to search the configuration repository
for systems that meet certain criteria. The query object is created within
a query library.
- (5) A method for filtering and sorting requirements
in views by limiting either the values of one or more attributes or traceability
and specifying the order in which to display the filtered requirements. See
also sorting.
- (6) A reusable request for
information about one or more model elements
-
query block
- The part of a query that
is represented by one of the FROM clauses. Each FROM clause can have multiple
query blocks, depending on how DB2 for z/OS processes the query.
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query body
- The part of a query that
contains the XQuery expression. See also query prolog.
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Query by Example (QBE)
- A language
used to write queries graphically.
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Query by Image Content (QBIC)
- A query
technology that enables searches based on visual content, called features,
rather than plain text. Using QBIC, you can search for objects based on their
visual characteristics, such as color and texture.
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query class
- In Query Patroller, a
mechanism that allows queries to be grouped and run according to their sizes.
Query classes allow the flow of queries on a database to be controlled, ensuring
that resources are shared among queries in the different size groupings (query
classes).
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query command
- The name of an action,
and any associated parameters, that can be performed by DB2 for i5/OS query
management. The query commands include ERASE, EXIT, EXPORT, GET, IMPORT, PRINT,
RUN, SAVE, SET, and START.
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query command procedure
- In DB2 for
i5/OS query management, a type of query procedure that contains a subset of
the query commands allowed in a query procedure. The query command procedure
can be used for initializing global variables.
-
query compatibility
- See index matching.
-
query controller
- The server component
of the Query Patroller system, which works with the DB2 database server to
manage queries.
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query CP parallelism
- Parallel execution
of a single query, which is accomplished by using multiple tasks. See also
sysplex query parallelism.
-
query definition
- In Query for i5/OS,
information about a query that is stored in the system. The system-recognized
identifier for the object type is *QRYDFN.
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query expansion
- A supplement to the
user's seach string to improve search retrieval results. A search string such
as "phone" may be expanded to "phone, phones, telephone, telephones, mobile
phone, cellular phone".
-
Query for i5/OS
- The IBM licensed
program used to select, format, and analyze information from data files to
produce reports and other files.
-
query instance
- In DB2 for i5/OS query
management, a collection of system resources and a set of query commands within
an application program.
-
query I/O parallelism
- Parallel access
of data, which is accomplished by triggering multiple I/O requests within
a single query.
-
query management
- A function of DB2
for i5/OS that provides query and report writing by using Structured Query
Language (SQL).
-
Query Management Facility (QMF)
- An IBM query and report writing facility that supports a variety of tasks
such as data entry, query building, administration, and report analysis.
-
query management object
- In DB2 for
i5/OS query management, a collective term to describe any of the query management
objects: query, form, or procedure.
-
Query Manager
- See DB2 Query Manager.
-
query mode
- In DB2 for i5/OS query
management, the processing mode associated with a query instance.
-
query optimization class
- A set of
query rewrite rules and optimization techniques for compiling queries.
-
query optimizer
- A component of the
SQL and XQuery 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. See also compensation.
-
Query Patroller Center
- The graphical
interface for administering Query Patroller. The Query Patroller Center can
be used to monitor and control the flow of queries, manage users, and view
query information.
-
query prolog
- In DB2 XQuery, a series
of declarations that defines the processing environment for a query. See also
query body.
-
query statement
- See query.
-
query status
- In Query Patroller,
the processing state of a managed query: initial (intercepted), running, done,
held, queued, canceled, aborted, rejected, or unknown. See also managed query.
-
query string
- (1) A character string that
specifies the properties and property values for a query. You can create the
query string in an application and pass it to the query.
- (2) An input
parameter that specifies the statistical data to be retrieved.
-
query submission preferences
- In Query
Patroller, a set of characteristics for a submitter that the submitter can
view and update. See also submitter.
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question pool
- A set of questions
that a Virtual Classroom instructor develops when creating a course that he
or she plans to ask at some point during a session. For example, during a
session an instructor might want to ask questions to get a sense of whether
the students are understanding the course materials.
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queue
- (1) A data structure for processing
work in which the first element added to the queue is the first element processed.
This order is referred to as first-in first-out (FIFO).
- (2) A line
or list of items waiting to be processed; for example, work to be performed
or messages to be displayed or transmitted.
- (3) A WebSphere MQ object
to which message queuing applications can put messages, and from which they
can get messages.
- (4) A logical subdivision of the MERVA queue data
set used to store the messages associated with a MERVA message-processing
function. A queue has the same name as the message-processing function with
which it is associated.
- (5) A sequence with restricted access in which
elements can only be added at the back end (or bottom) and removed from the
front end (or top). A queue is characterized by first-in, first-out behavior
and chronological order.
- (6) A WebSphere MQ object that holds messages
for message queueing applications. A queue is owned and maintained by a queue
manager.
- (7) A constructed and maintained list of items that are waiting
to be processed. A collection of data objects with the same name in a Shared
Queue.
-
queue buffer (Qbuffer)
- An IMS queue
manager incore buffer that is used to keep the working copy of an IMS message
segment.
-
queued call
- A telephone call that
has been placed on hold and is waiting in the queue of telephone calls to
be serviced by a system resource (such as an ACD group).
-
queue depth
- In SNADS, the number
of distribution items on the distribution queue waiting to be sent.
-
queue destination
- A service integration
bus destination that is used for point-to-point messaging.
-
queued sequential access method (QSAM)
- An access method for storing and retrieving logical records in a continuous
sequence. Input data blocks awaiting processing or output data blocks awaiting
transfer to auxiliary storage are queued on the system to minimize delays
in I/O operations.
-
queue element
- A message and its related
control information stored in a data record in the MERVA ESA Queue Data Set.
-
queue latency
- In Q replication and
event publishing, an approximate measurement of the difference between the
time that the Q Capture program commits data to WebSphere MQSeries and the
time that WebSphere MQSeries makes the data available to the Q Apply program
or a receiving application. This is a subset of the end-to-end latency in
a replication scenario or an event publishing scenario. See also Q Apply latency, Q Capture latency, end-to-end latency.
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queue management
- A MERVA service
function that handles the storing of messages in, and the retrieval of messages
from, the queues of message-processing functions.
-
queue manager
- (1) A system program that
provides queuing services to applications. It provides an application programming
interface so that programs can access messages on the queues that the queue
manager owns.
- (2) An object that defines the attributes of a particular
queue manager.
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Queue Manager (QMGR)
- (1) A component
of CICSPlex SM that creates and manages queues of data in a cache that is
shared by a CMAS and its local MASs.
- (2) An IMS component that manages
IMS messages and the space the messages occupy. The IMS Queue Manager is part
of a DB/DC or DCCTL environment.
-
queue manager event
- An event that
indicates one of the following: an error condition has occurred in relation
to the resources used by a queue manager. For example, a queue is unavailable,
or a significant change has occurred in the queue manager. For example, a
queue manager has stopped or started.
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queue manager level security
- In WebSphere
MQ for z/OS, the authorization checks that are performed using RACF profiles
specific to a queue manager.
-
queue map
- In Q replication and event
publishing, an object that contains the settings for how Q replication programs
process transactions and identifies the WebSphere MQSeries queues that are
used in a replication or event publishing scenario. See also publishing queue map, replication queue map.
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queue name (Qname)
- The name of a
queue on Shared Queues upon which data objects reside. The queue name is 16
bytes long, left justified, padded with blanks. The first byte of the client
queue name is the queue type. A client queue name of blanks or zeroes is supported.
-
queue priority
- In Query Patroller,
a numerical value that represents the priority assigned to a query when a
query is submitted.
-
queue sequence number (QSN)
- A sequence
number that is assigned to the messages stored in a logical queue by MERVA
ESA queue management in ascending order. The QSN is always unique in a queue.
It is reset to zero when the queue data set is formatted, or when a queue
management restart is carried out and the queue is empty.
-
queue-sharing group
- In WebSphere
MQ for z/OS, a group of queue managers in the same sysplex that can access
a single set of object definitions stored in the shared repository, and a
single set of shared queues stored in the coupling facility. See also shared queue.
-
queue-sharing group level security
- In WebSphere MQ for z/OS, the authorization checks that are performed using
RACF profiles that are shared by all queue managers in a queue-sharing group.
-
queue structure
- A structure managed
by CQS that contains data in queues.
-
queue type
- A grouping of shared queues
on the coupling facility list structure whose meaning is client defined or
CQS defined.
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queuing network
- A group of interconnected
components.
-
quick link
- An association between
a Uniform Resource Identifier (URI) and keywords or phrases.
-
quick publish
- To copy managed assets
from a task group to the production server after the commit of the managed
assets from the task group to the production-ready data on the authoring server
is successful. See also production server, authoring server, workspace, managed asset, task group, commit, production-ready data.
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quick query
- A query that is run using
only a file name and possibly some record selection specifications; an undefined
query.
-
quick start
- A type of warm start
that can be performed in a multi-access spool (MAS) configuration.
-
QuickStep pad
- A window containing
a variable number of buttons that can be clicked on with a mouse. Each button
can be assigned a macroinstruction that issues a predefined sequence of keystrokes
or commands.
-
quiesce
- To end a process or shut
down a system after allowing normal completion of active operations.
-
quiesced
- Pertaining to the state
of an instance or database when it has no active transactions, the buffer
pools are flushed, no new transactions are allowed, and no new connections
are allowed.
-
quiesced shutdown
- (1) In WebSphere MQ,
a shutdown of a queue manager that allows all connected applications to disconnect.
See also forced shutdown, immediate shutdown, preemptive shutdown.
- (2) A type of shutdown of the CICS adapter where the adapter disconnects
from WebSphere MQ, but only after all the currently active tasks have been
completed. See also forced shutdown.
-
quiesce point
- A point at which data
is consistent as a result of running the DB2 QUIESCE utility.
-
quiesce time
- A time of day after
which an automatic function does not start processing any more volumes.
-
quiescing
- (1) In WebSphere MQ, the state
of a queue manager before it stops. In this state, programs are allowed to
finish processing, but no new programs are allowed to start.
- (2) The process of bringing a device or a system to a halt by rejection of new
requests for work.
-
quorum disk
- (1) The disk accessed exclusively
by Microsoft Cluster Server to store the cluster recovery log, and to determine
whether a server is up or down. Only one server can own the quorum disk at
a time. Servers in the cluster can negotiate for the ownership.
- (2) A managed disk (MDisk) that contains a reserved area used exclusively for
cluster management. The quorum disk is accessed in the event that it is necessary
to determine which half of the cluster will continue to read and write data.
-
quorum index
- The pointer that indicates
the order used to resolve a tie. Nodes attempt to lock the first quorum disk
(index 0), followed by the next disk (index 1), and finally the last disk
(index 2). The tie is broken by the node that locks them first.
-
quorum node
- A node in the cluster
that is counted to determine whether a quorum exists.
-
quota
- (1) A size limitation, such as
the limit on the amount of disk space or size of a file set
- (2) The
amount of disk space and number of inodes assigned as upper limits for a specified
user, group of users, or fileset.
-
quota management
- The allocation of
disk blocks to the other nodes writing to the file system, and comparison
of the allocated space to quota limits at regular intervals.
-
quotation mark
- The characters " and '.
-
quote
- To mask the special meaning
of certain characters, causing the characters to be taken literally.
-
quoted name
- See delimited identifier.
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RA
- See repeat
to address.
-
RACE
- See receive-any
control element.
-
race condition
- A condition that occurs
when two or more independent tasks simultaneously attempt to access and modify
the same state information. This condition can lead to inconsistent behavior
of the system and is a fundamental issue in concurrent system design.
-
RACF
- See Resource
Access Control Facility.
-
RACF always call
- The policy by which
DFSMSdfp checks all data sets automatically for discrete or generic Resource
Access Control Facility (RACF) profiles to verify access authority.
-
RACF authorization
- The facility for
checking a user's level of access to a resource against the user's desired
access or the result of that check.
-
RACF database
- A collection of interrelated
or independent data items stored together without redundancy, to serve the
Resource Access Control Facility (RACF).
-
RACF-indicated
- Pertaining to a data
set for which the RACF indicator is set on. If a data set is RACF-indicated,
a user can access the data set only if a RACF profile or an entry in the global
access checking table exists for that data set.
-
RACF-protected
- Pertaining to resources
that are defined to RACF. A data set that is RACF-protected by a discrete
profile must also be RACF-indicated.
-
RACF remote sharing facility (RRSF)
- A set of RACF functions that links together multiple RACF databases, allowing
remote RACF administration and password synchronization.
-
RACF report writer
- A RACF function
that produces reports on system use and resource use from information found
in the RACF System Management Facility (SMF) records.
-
RACF segment
- The portion of a RACF
profile that contains basic information needed to define a user, group, or
resource to RACF.
-
RACHECK request
- In RACF, the issuing
of the RACHECK macro or the RACROUTE macro with REQUEST=AUTH specified. The
primary function of a RACHECK request is to check a user's authorization to
a RACF-protected resource or function. See also authorization
checking, FRACHECK request, RACROUTE.
-
RACINIT request
- In RACF, the issuing
of the RACINIT macro or the RACROUTE macro with REQUEST=VERIFY or REQUEST=VERIFYX
specified. A RACINIT request is used to verify the authority of a user to
enter work into the system. See also RACROUTE.
-
rack
- (1) A free-standing structure or
frame that can hold multiple servers and expansion units.
- (2) See enclosure.
-
rack configuration list
- A list of
all of the equipment within the rack and the logic cards within the card enclosure.
-
rack number
- In DFSMSrmm, a 6-character
identifier that corresponds to a specific volume's shelf location in the installation's
removable media library; the rack number is the identifier used on the external
label of the volume to identify it. See also cell, shelf location.
-
rack pool
- In DFSMSrmm, a group of
shelves that contains volumes that are generally read-only.
-
rack stabilizer
- A plate that holds
the rack stable or steady when a device is pulled out for service.
-
RACL
- See Random
Automated Cartridge Loader.
-
RACROUTE
- In RACF, a macro that provides
a means of calling RACF to provide security functions. See also FRACHECK request, RACHECK request, RACINIT request.
-
RAD
- See rapid
application development.
-
RAD file
- A file containing deployment
objects such as task templates, system profiles and software packages used
to archive data or to transfer data between two provisioning servers. A RAD
file has a .rad extension.
-
radio button
- In graphical user interfaces,
a control that comprises a circle with text beside it, representing one of
set of mutually exclusive choices. The circle is partially filled when a choice
is selected.
-
radio frequency (RF)
- An alternating
current that generates an electromagnetic field when applied to an antenna.
The generated electromagnetic field is suitable for wireless broadcasting
and communications.
-
radix character
- The character that
separates the integer part of a number from the fractional part. X/Open .
-
radix-tree index
- In DB2 for i5/OS,
an object that provides random access to rows in a database table. See also
encoded-vector index.
-
RAI
- See remote
alarm indication.
-
RAIA
- See receive-any
input area.
-
RAID
- See Redundant
Array of Independent Disks.
-
RAID 0
- A data striping technique,
which is commonly called RAID Level 0 or RAID 0 because of its similarity
to common, RAID, data-mapping techniques. It includes no data protection,
however, so, strictly speaking, the appellation RAID is a misnomer. RAID 0
is also known as data striping.
-
RAID 1
- A form of storage array in
which two or more identical copies of data are maintained on separate media.
-
RAID 10
- A combination of RAID 0 and
RAID 1 in which two identical copies of striped data exist, but there is no
parity.
-
RAID 3
- A form of parity RAID in which
all disks are assumed to be rotationally synchronized, and in which the data
stripe size is no larger than the exported block size.
-
RAID 5
- A form of parity RAID in which
the disks operate independently, the data stripe size is no smaller than the
exported block size, and parity check data is distributed across the array's
disks
-
RAID 6
- Any form of RAID that can
continue to process read and write requests to all of an array's virtual disks
in the presence of two concurrent disk failures.
-
rail
- Hardware attached inside a rack
to hold devices that are designated as installable in a rack. See also slide.
-
RAM
- See random
access memory.
-
RAMP-C
- See commercial processing workload.
-
random access
- (1) In COBOL, an access
method in which the program-specified value of a key data item identifies
the logical record that is obtained from, deleted from, or placed into a relative
or indexed file.
- (2) A process where individual records can be referred
to in a nonsequential manner. See also access mode.
- (3) Pertaining to a computer's process of reading data from
and writing data to storage in a nonsequential manner.
-
random access memory (RAM)
- Computer
memory in which any storage location can be accessed directly. See also disk unit.
-
Random Automated Cartridge Loader (RACL)
- A cartridge loader that includes individual drives that can have their
own facility to use an automated tape library.
-
random by key
- A processing method
for files in which the value in the key field identifies the records to be
processed.
-
random by relative record number
- A processing method for files in which relative record numbers identify the
records to be processed.
-
randomization
- The process of distributing
schedule start times for different clients within a specified percentage of
the schedule's startup window.
-
random number
- A number obtained by
chance.
-
random processing
- A method of processing
in which records can be read from, written to, or deleted from a file order
requested by the program that is using them. See also consecutive processing, sequential processing.
-
random read
- The normal OSAM buffering
method, which reads only one block with each I/O operation.
-
range-clustered table (RCT)
- A table
whose data is tightly clustered across one or more columns. Each record in
the table has a predetermined offset from the logical start of the table,
which allows rapid access to the data.
-
range-partitioned data space
- A type
of universal table space that is based on partitioning ranges and that contains
a single table. See also partition-by growth table
space, universal table space.
-
rank
- (1) An integer value that signifies
the relevance of a given part to the results of a query. A higher rank signifies
a closer match.
- (2) An attribute of a use case, or scenario that describes
its impact on the architecture, or its importance for a release.
- (3) See array.
-
ranking
- The assignment of an interger
value to each document in the search results from a query. The order of the
documents in the search results is based on the relevance to the query. A
higher rank signifies a closer match. See also dynamic
ranking, static ranking.
-
RAP
- See root
anchor point.
-
rapid application development (RAD)
- An environment supported by the workbench in which a server project can be
configured to repeatedly deploy a server configuration (that contains message
flows and message sets) to the broker with a single toolbar button click.
-
rapid deployment tool
- One of a set
of tools to rapidly develop and deploy J2EE artifacts on the server and package
the J2EE artifacts into the deployed EAR file.
-
Rapid Network Reconnect (RNR)
- A function
of IMS that automatically reconnects IMS VTAM terminal sessions across outages
(IMS, z/OS, or VTAM) and subsequent IMS restarts on the same or different
z/OS systems within a sysplex.
-
Rapid Transport Protocol (RTP)
- A
connection-oriented, full-duplex transport protocol for carrying session traffic
over High-Performance Routing (HPR) routes.
-
Rapid Transport Protocol connection (RTP connection)
- A connection between two High-Performance Routing (HPR) nodes
that may traverse one or more intermediate HPR nodes and links. The connection
endpoints provide error recovery and adaptive rate-based flow control for
the connection traffic, and nondisruptive switching of the underlying physical
path in the case of route outage. The intermediate HPR nodes minimize their
routing overhead using automatic network routing (ANR) protocols, which rely
on header information to permit efficient source routing and prioritized transmission
along the RTP connection.
-
RAR
- (1) See route
addition resistance.
- (2) See resource adapter
archive.
-
raster font
- A font in which the characters
are defined directly by the raster bit map. See also outline font.
-
raster overlay
- See raster pattern overlay.
-
raster pattern
- A series of picture
elements (pels) arranged in scan lines to form an image.
-
raster pattern overlay
- An overlay
loaded in a printer as a raster pattern, rather than as a sequence of commands.
See also coded overlay.
-
raster pattern storage (RPS)
- An area
of storage that holds raster patterns for fonts and images.
-
rational number
- A real number that
is the quotient of an integer divided by an integer other than zero.
-
Rational process workbench (RPW)
- A process customization and publishing tool that enables process engineers
to accelerate delivery of customized software development process, visually
model process using Unified Modeling Language, and leverage the best practices
captured in the RUP.
-
Rational Unified Process (RUP)
- A
configurable software development process platform that is used to assign
and manage tasks and responsibilities within a development organization.
-
R_A_TOV
- See resource allocation timeout value.
-
raw time
- The time taken by the application
to run, including the overhead introduced by profiling the application.
-
RBA
- See relative
byte address.
-
RBBI
- See rule-based
break iterator.
-
RBR
- See rollback
required.
-
RBS
- See robbed-bit
signaling.
-
RC
- A REXX special variable set to
the return code from any executed host command or subcommand. It is also set
to the return code when the conditions ERROR, FAILURE, and SYNTAX are trapped.
-
RC5
- An encryption technology for
use in wireless clients and servers.
-
RCB
- See record
control byte.
-
RCD
- See read
cache device.
-
RC message
- Recovered message; that
is, an IP message that was copied from the control queue of an inoperable
or closed ASP via the recover command.
-
RCMS
- See remote
change management server.
-
RCP
- See rich
client platform.
-
RCT
- (1) See resource
control table.
- (2) See range-clustered table.
-
rCxt block
- See remote context block.
-
RDB
- See relational
database.
-
RDB directory
- The directory where
remote databases in the network are registered. Information in a directory
tells the system which communications parameters to use to connect to a remote
database. The RDB directory also contains the name of the local database.
-
RDBMS
- See relational database management system.
-
RDBMS Interface Module (RIM)
- The
module in the distributed object database that contains information about
the installation of the relational database management system (RDBMS).
-
RDF
- (1) See record
definition field.
- (2) See Resource Description
Framework.
-
RDM
- See resource
definition macro.
-
RDMA
- See Remote
Direct Memory Access.
-
RDN
- See relative
distinguished name.
-
RDO
- See resource
definition online.
-
RDS
- (1) See restart
data set.
- (2) See Relational Data Services.
-
RDSA
- See read-only
dynamic storage area.
-
RDT
- See resource
definition table.
-
RDW
- See record
descriptor word.
-
RE
- (1) See remote
extension.
- (2) See regular expression.
-
read access
- An access intent that
establishes the intent of an application to read the database (without making
modifications) and to be protected from an updater's incomplete changes.
It allows other applications to share the database. See also scheduling intent.
-
read access list
- A list that restricts
a form so that only specified users can read documents created from the form.
Use the reader's field to control access on a document-by-document basis.
-
read access state
- A state indicating
that only read access to a table is allowed.
-
readahead prefetching
- A method of
prefetching pages by looking ahead in a scan, which results in asynchronous
retrieval of pages even though those pages are not located sequentially on
disk.
-
read authority
- (1) A data authority that
allows the user to look at the contents of an entry in an object.
- (2) An authority subset that allows the user to read entries in an object. The
system-recognized identifier is *R. *R authority combines object operational
authority and read authority.
-
read cache device (RCD)
- A volatile
solid-state disk that is optimized for use as memory for the extended adaptive
cache.
-
reader
- (1) An internal program that reads
jobs from an input device or a database file and places them on a job queue.
- (2) In RJE, a program that reads jobs from a database file or interactive
display station and sends them to the host system.
-
reader access
- An access level with
which users can only read documents.
-
reader DSP
- A dynamic support program
(DSP) that transfers job-related information, such as control statements,
from an input device to the spool data set.
-
read/execute authority
- An object
authority that allows the user to read entries in an object, run a program,
and search a library or directory. Read/execute authority combines object
operational authority, read authority, and execute authority. The system-recognized
identifier is *RX.
-
read-from-invited-program-devices operation
- An input operation that waits for input from any one of the invited
program devices for a user-specified time. See also read-from-one-program-device operation.
-
read-from-one-program-device operation
- An input operation that will not complete until the specified device
has responded with input. See also read-from-invited-program-devices
operation.
-
read hit
- Data requested by the read
operation that is in the cache.
-
readiness level
- For an RSR database-level
tracker, the level that determines whether a shadow database is ready to
apply database changes as they are received from the active IMS. See also
recovery-readiness-level database.
-
read integrity
- An attribute of a
read request, which ensures the integrity of the data passed to a program
that issues a read-only request. CICS recognizes two forms of read integrity:
consistent and repeatable. See also dirty read, repeatable, consistent.
-
read intent
- The type of access intent
that subsystems use to read data from a database.
-
read lock
- A lock that prevents any
other process from setting a write lock on any part of the protected area.
See also write lock.
-
read miss
- Data requested by the read
operation that is not in the cache.
-
read-only
- Pertaining to data that
can be read but cannot be modified.
-
read-only access
- An access level
that permits a user or an application to read a document or record but not
to update it. See also scheduling intent.
-
read-only dynamic storage area (RDSA)
- The key-0 storage area for all reentrant programs and tables below the
16MB boundary.
-
read-only memory (ROM)
- Memory in
which stored data cannot be changed by the user except under special conditions.
-
read-only variable
- An automatic class
selection (ACS) language variable that contains data set or system-derived
information. It can be referenced, but not altered, in an ACS routine.
-
read operation
- An input operation
that obtains data from a file or device and passes it to a program.
-
read stability (RS)
- An isolation
level that prevents any row that is read from being changed by other applications
until the transaction is completed. For WITH HOLD cursors, this applies to
when the rows were actually read. For read-only WITH HOLD cursors, the rows
might have actually been read in a prior transaction. RS also prevents any
row that is changed by other applications from being read until the change
is committed. A transaction that issues the same query more than once will
read the same rows again, but it might also read additional phantom rows that
were modified and committed by an application that is running concurrently.
See also cursor stability, repeatable read, uncommitted read, isolation level.
-
read trigger
- A trigger that is activated
by a read operation on the table or view that is specified in the trigger
definition. See also insert trigger, trigger, instead of trigger, update trigger.
-
read with integrity
- See read access.
-
read without integrity
- See read-only access.
-
read/write authority
- An object authority
that allows the user to add, change, delete, and read entries in an object.
Read/write authority combines object operational authority, read authority,
add authority, update authority, and delete authority. The system-recognized
identifier is *RW.
-
read/write/execute authority
- An object
authority that allows the user to add, change, delete, and read execute entries
in an object, run a program, and search a library or directory. Read/write/execute
authority combines object operational authority, read authority, add authority,
update authority, delete authority, and execute authority. The system-recognized
identifier is *RWX.
-
read/write head
- The data sensing
and recording unit of the diskette drive or tape drive.
-
read/write variable
- An automatic
class selection (ACS) language variable that is assigned a value within an
ACS routine. It can be referenced, and each ACS routine assigns a value to
its own, unique, read/write variable.
-
ready
- Pertaining to a status where
all the loaded and mounted image catalog entries are available for use by
the active virtual optical device. Any image catalog entry with a status of
unloaded is not available for use by the virtual optical device. The image
catalog can be made ready by using the LODIMGCLG (Load Image Catalog) command
with OPTION(*LOAD).
-
Ready for IBM Tivoli software
- Pertaining
to a product that has passed rigorous product certification testing to ensure
that the product delivers seamless integration with Tivoli technology management
solutions and provides true end-to-end technology management functionality.
A product that has passed this certification testing carries the Ready for
IBM Tivoli software logo.
-
ready queue
- A MERVA queue used by
SWIFT Link to collect SWIFT messages that are ready for sending to the SWIFT
network.
-
ready to send
- A hardware handshake
or signal that is sent by a device to indicate that it is ready to send data.
-
real attribute
- An attribute that
must have a value.
-
real GID
- See real group ID.
-
real group ID (real GID)
- (1) For each
user, the group ID defined in the password file.
- (2) The attribute
of a process that, at the time of process creation, identifies the group of
the user who created the process. This value is subject to change during the
process lifetime.
-
realization relationship
- In UML,
a dependency relationship in which one class implements the behavior that
another class specifies. See also dependency relationship, implementation relationship.
-
realize
- In the Web diagram editor,
to associate a node with an actual resource by creating that resource or by
editing the node's path so that it points to an existing resource. See also
unrealized.
-
realizes relationship
- See realization relationship.
-
realm
- (1) In the Kerberos protocol, the
set of principals for which a specific key distribution center (KDC) is the
authenticating authority.
- (2) A grouping of customers, organized by
division, region, or company, which is used to separate customer data.
- (3) A collection of resource managers that honor a common set of user credentials
and authorizations.
-
realm name
- The machine name of a
user registry.
-
realm trust
- The Kerberos protocol
either searches the configuration file to determine realm trust or by default
looks for trust relationships within the realm hierarchy. Using Trusted realms
in network authentication service allows you to bypass this process and creates
a shortcut for authentication. Realm trust can be used in networks where realms
are in different domains. For example, if a company has one realm at NY.myco.com
and another at LA.myco.com, then you can establish trust between these two
realms. If two realms trust each other their associated KDCs must share a
key. Before creating a shortcut, you must set up the KDCs to trust each other.
-
real object
- An object that represents
an actual resource.
-
real optical library
- A physical storage
device that houses optical disk drives and optical cartridges, and contains
a mechanism for moving optical disks between a cartridge storage area and
optical disk drives. See also pseudo optical library.
-
real resource
- (1) In VTAM, a resource
identified by its real name and its real network identifier.
- (2) In the NetView Graphic Monitor Facility, an individual network resource represented
by a real object.
-
real storage
- The main storage in
a virtual storage system. Physically, real storage and main storage are identical.
Conceptually, however, real storage represents only part of the range of addresses
available to the user of a virtual storage system.
-
real-time
- Pertaining to the processing
of data by a computer in connection with another process outside the computer
according to time requirements imposed by the outside process.
-
real time
- The processing of information
that returns a result so rapidly that the interaction appears to be instantaneous.
-
real-time analysis (RTA)
- In CICSPlex
SM, a function that provides the automatic notification of requested error
conditions and all aspects of a resource's status. The notifications appear
in console messages, or generic NetView for OS/390 alerts, or both.
-
real-time gross settlement system (RTGS)
- A payment system that settles, in real time, individual payments across
central bank accounts. Payments must be secured by funds at the time the payment
is made.
-
real-time replication
- See synchronous replication.
-
Real Time Streaming Protocol (RTSP)
- A protocol for streamed multimedia data over IP networks. Generally, RTSP
offers services similar to a video store with delivery services, a VCR, or
cable television. "VCR style" control functionality includes pause, fast forward,
reverse, and absolute positioning.
-
Real-Time Transport Protocol (RTP)
- A protocol that provides end-to-end network transport functions suitable for
applications transmitting real-time data, such as audio, video or simulation
data, over multicast or unicast network services.
-
real UID
- See real user ID.
-
real user ID (real UID)
- (1) For each
user, the user ID that is specified in the /etc/passwd file.
- (2) The attribute of a process that, at the time a process is created, identifies
the user who created the process.
-
reasonable resource loaded value (RRLV)
- A value used by PSF to keep the number of resources loaded at a manageable
level. At data set end, PSF deletes resources for a particular resource type
until this value is reached.
-
reason code
- (1) A return code that describes
the reason for the failure or partial success of a Message Queue Interface
(MQI) call.
- (2) A value used to indicate the specific reason for an
event or condition.
-
reassembly
- In OSI, a function performed
by an (N)-entity to map multiple (N)-protocol-data-units into one (N)-service-data-unit.
Reassembly is the opposite of segmenting.
-
reassign
- To mark a disk sector as
damaged. The marked disk sector points to another sector location where the
data from the damaged sector is moved.
-
reassociation
- An optimization technique
that rearranges the sequence of calculations in a subscript expression producing
more candidates for common expression elimination.
-
reattach
- In cross-site mirroring,
to reassociate the mirror copy with its production copy after user operations
on the mirror copy are complete. When the mirror copy is reattached, it is
automatically synchronized to match the production copy again. All data on
the mirror copy prior to when it is reattached to the production copy is cleared.
-
reattachment event
- An event whose
firing has caused an activity to be activated.
-
reattachment queue
- A list of the
reattachment events that have caused a particular activity to be activated.
Each activity has a reattachment queue associated with it. The queue may be
empty. Events remain on the reattachment queue until they are retrieved by
the activity, or until a syncpoint occurs.
-
rebalance
- To restripe and redistribute
data across the available hard disks after a disk or disks have been removed
from a file system.
-
rebase
- A ClearCase operation that
makes a development work area current with the set of versions represented
by a more recent baseline in another stream, usually the project's integration
stream or a feature-specific development stream.
-
rebind
- (1) To create a package for an
application program by using information from the previously bound package.
For example, in DB2 Database for Linux, UNIX, and Windows and DB2 for z/OS,
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. See also automatic rebind, implicit rebind, explicit rebind.
- (2) To request renewal of a lease from a system
on a particular network.
-
rebuild
- To restore a database or
a subset of its table spaces by using a set of table space restore operations.
-
rebuild maintenance
- A method of maintaining
keyed access paths for database files. This method updates the access path
only while the file is open, not when the file is closed; the access path
is rebuilt when the file is opened. See also delayed
maintenance, immediate maintenance.
-
rebuild phase
- The stage that a database
is in from the time that the database successfully completes a rebuild restore
operation until the first time that the database is rolled forward and log
records start being processed.
-
recall
- (1) To access files that have
been migrated from workstations to server storage.
- (2) The process
of moving a migrated data set from a level 1 or level 2 volume to a volume
that is or is not managed by DFSMShsm. See also hierarchical
storage management.
-
recapture
- In update-anywhere replication,
to capture changes at a replica table and forward these changes to the master
table or to other replica tables.
-
receive
- The handling of a stimulus
passed from a sender instance. See also receiver, sender.
-
receive-any control element (RACE)
- Type of control field held in the CICS receive-any pool set aside for VTAM
receive-any operations. The number of RACEs maintained depends on the RAPOOL
and MXT system initialization parameters and on the number of active tasks.
-
receive-any input area (RAIA)
- Type
of input area held in the CICS receive-any pool set aside for VTAM receive-any
operations. The number of RACEs maintained depends on the RAPOOL and MXT system
initialization parameters and on the number of active tasks.
-
received line signal detector (RLSD)
- See data carrier detect.
-
received page counter
- See channel counter.
-
receive exit
- A type of channel exit
program that is called just after the message channel agent (MCA) has regained
control following a communications receive and has received a unit of data
from a communications connection. See also send exit.
-
receive mode
- A time during which
the BSC adapter looks for synchronization characters, and stores the data
characters in main storage.
-
receive not ready (RNR)
- In communications,
a data link command or response that indicates a temporary condition of being
unable to accept incoming frames.
-
receive queue
- In Q replication, a
WebSphere MQ message queue that is used by a Q Apply program to receive transactions
that are captured by a Q Capture program.
-
receiver
- (1) In hardware, a functional
unit that converts small electronic signals to signals that control a device.
- (2) The object handling a stimulus passed from a sender object. See
also sender, receive.
- (3) A defined role in WebSphere Commerce that receives inventory
at the fulfillment center, tracks expected inventory records and ad hoc receipts
for ordered products, and receives returned products as a result of customer
returns. See also logistics manager.
- (4) A component that accepts documents from external partners and from back end
applications and stores them in a file system for the Document Manager to
process. Specifically, it receives a document over a supported transport protocol,
writes the document and metadata relating to the document to the shared file
system, records any transport-specific data to the metadata file, and completes
any transport-specific technical acknowledgment.
-
receiver bean
- In extended messaging,
a message-driven bean or a session bean. A message-driven bean is invoked
when a message arrives at a JMS destination for which a listener is active.
A session bean polls a JMS destination until a message arrives, gets the parsed
message as an object, and can use methods to retrieve the message data.
-
receiver chain
- The journal receivers
presently or previously attached to the same journal. Each journal receiver,
except the first one, has a previous receiver that was attached before the
current receiver. Each journal receiver, except the currently attached receiver,
has a next receiver.
-
receiver chain break
- A logical break
in a receiver chain.
-
receiver channel
- In message queuing,
a channel that responds to a sender channel, takes messages from a communication
link, and puts them on a local queue.
-
receiver directory
- Summary information
about the journal receivers that are or were attached to the specified journal
and are still known to the system.
-
receive ready (RR)
- In communications,
a data link command or response that indicates that a station is ready to
receive protocol data units. Receive ready also acknowledges receipt of protocol
data units.
-
receive timeout
- In data communications,
a condition that occurs when no data is received in a given period of time.
-
receiving cross-domain key
- In Cryptographic
Support, a cross-domain key used to decrypt a data-encrypting key that was
encrypted by another location.
-
recency, frequency, monetary (RFM)
- A technique used to determine which customers are the best ones by examining
how recently a customer has purchased (recency), how often they purchase (frequency),
and how much the customer spends (monetary).
-
receptacle
- A hollowed electrical
fitting that contains the live parts of a circuit.
-
reception
- A declaration that a classifier
is prepared to react to the receipt of a signal.
-
RECFMS
- See record formatted maintenance statistics.
-
recipient address
- A string of data
that represents the address associated with the recipient of the message.
The contents and format of the string are not defined by the mail server framework.
The address type associated with the recipient address is assumed to define
the contents of the recipient address field.
-
recipient history tree
- A structure
that represents the changes to the recipient list, so that a recipient can
be traced back to the recipient entry in the original recipient list passed
using the Create Mail Message application program interface (API).
-
Recognition Engine server
- In WebSphere
Voice Server, the software that carries out the speech recognition and forwards
the results to the client. This consists of one 'Tsm router' and at least
one 'tsmp' and one 'engine'.
-
recognition profile
- In the 3270 Terminal
Services tool, a list of the identifiers that uniquely identify the state
of a screen, that is, the set of conditions that apply to the screen at the
time the screen was imported from the host. Each screen state needs to be
uniquely defined in its own recognition profile.
-
recognition table
- In the 3270 terminal
services development tool, the table that appears in the screen editor and
provides a screen definition view and a recognition profile view of the screen
that was imported.
-
recombining
- In OSI, a function performed
by an entity that is the reverse of splitting.
-
Recommendation X.21 (X.21)
- A document,
CCITT Recommendation X.21, that outlines standards for a general-purpose interface
between data terminal equipment (DTE) and data circuit-terminating equipment
(DCE) for synchronous operations on a public data network.
-
Recommendation X.21 bis
- A document,
CCITT Recommendation X.21 bis, that outlines standards for the interface between
data terminal equipment (DTE) and V-series data circuit-terminating equipment
(DCE) for synchronous operations on a public data network.
-
Recommendation X.31
- A document, CCITT
Recommendation X.31, that outlines standards for the X.25 protocol over integrated
services digital networks (ISDNs).
-
reconciliation
- In identity management,
the process of synchronizing the accounts and supporting data on the central
data repository with the accounts and supporting data on the managed resource.
-
RECON data sets
- See recovery control data set.
-
reconfiguration
- The process of adding
hardware units to, or removing hardware units from, a configuration.
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record
- (1) The storage representation
of a row or other data.
- (2) A group of related data, words, or fields
treated as a unit, such as one name, address, and telephone number.
- (3) In programming languages, an aggregate that consists of data objects,
possibly with different attributes, that usually have identifiers attached
to them. In some programming languages, records are called structures.
-
record address file
- In RPG, an input
file that indicates which records are to be read from another file and the
order in which the records are to be read.
-
record and playback
- A performance
monitoring function that is used to to record Web transactions and Microsoft
Windows applications, and then play back the recordings to assess transaction
performance and availability. See also playback policy.
-
record area
- In COBOL, a storage area
in which a record described in a record description entry in the File Section
is processed.
-
record control byte (RCB)
- In multileaving
telecommunications access method (MTAM), a control character used to identify
each record type within a transmission block.
-
record data
- Data sets with a record-oriented
structure that are accessed record by record. This data set structure is typical
of data sets on VM, MVS, and OS/400 systems. See also byte stream.
-
record definition field (RDF)
- In
the Virtual Storage Access Method (VSAM), a field stored as part of a stored
record segment; it contains the control information required to manage stored
record segments within a control interval. See also control interval definition field.
-
record description entry
- In COBOL,
the total set of data description entries associated with a particular record.
-
record descriptor
- Specifications
that describe how record format line data records are formatted into individual
print lines. Record descriptors are interpreted by PSF when formatting printed
output.
-
record descriptor word (RDW)
- Data
preceding a variable record that specifies the length of the entire record
including the RDW.
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recorded telephone conference call
- A telephone conference call that was scheduled as part of a Sametime meeting
and recorded. After the meeting has finished, users can dial the access number
to listen to the recorded call.
-
record format
- A named part of a file
that identifies records of a specified record format description.
-
record format definition
- In IDDU,
information that describes the arrangement or layout of fields in a record.
A record format definition resides in a data dictionary.
-
record format description
- A description
of the characteristics of the fields (for example, type and length) and the
arrangement of the fields in a record created by the user.
-
record format line data
- A form of
line data where each record is preceded by a 10-byte identifier. See also
line data.
-
record formatted maintenance statistics (RECFMS)
- A statistical record built by an SNA controller and usually solicited
by the host.
-
record ID code
- See record identification code.
-
record identification code (record ID code)
- Characters placed in a record to identify the record format.
-
record identifier (RID)
- A unique
identifier that the DB2 database manager uses internally to identify a row
of data in a table. See also row identifier.
-
record identifier pool (RID pool)
- An area of main storage that is used for sorting record identifiers during
list-prefetch processing.
-
record identifying indicator
- An indicator
that identifies the record just read.
-
record ID information object
- A Data
Interchange Services object that contains control information for ROD document
definitions. It identifies the type of ROD document definition being used
and where the record ID, if any, is located in the records associated with
the document definition.
-
recording
- The information from performance
snapshots that can be viewed at a later time.
-
recording format
- For a tape volume,
the format of the data on the tape, such as 18, 36, 128, 256, or 384 tracks.
-
record interface
- In PSF, coordinates
the transmitting of printer resources needed to print a document.
-
record key
- (1) In COBOL, a key field
whose contents identify a record within an indexed file.
- (2) In RPG,
all the key fields defined for the record type.
-
record layout
- In AFP Utilities, a
part of the printout format definition that defines how each field of a database
file record is formatted and printed by the print format utility.
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record length
- The total length of
all the columns in a table. The record length is the length of the data as
physically stored in the database. Records can be fixed or variable in length,
depending on how the columns are defined. If all columns are fixed-length
columns, the record is a fixed-length record. If one or more columns are varying-length
columns, the record is a varying-length record.
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record-level access
- A means of supporting
distributed files. Record-level access enables an application or user to read
and update individual records of files on a remote system without specifying
the data's location.
-
record-level sharing (RLS)
- See VSAM record-level sharing.
-
record-level specification
- A data
description specification coded on the same line as a record format name or
on lines immediately following a record format name (until the first field
is specified).
-
record-level subscriber (RLS)
- An
attribute of a user record that specifies which endpoints are subscribed to
the user record.
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record mode
- In MFS, the default input
mode in which fields are defined as occurring within a specific record sent
from the device. See also input mode, stream mode.
-
record name
- A user-defined name for
a record. The name is listed in a record description entry.
-
record number
- In COBOL, the ordinal
number of a record in the file whose organization is sequential.
-
record-only mode
- The operating mode
in which DFSMSrmm records information about volumes as they are used, but
does not validate or reject volumes. See also warning
mode, manual mode.
-
record oriented data (ROD)
- The type
of document definition used to describe proprietary document formats. One
of the supported document syntax types.
-
record oriented data dictionary (ROD dictionary)
- A logical grouping of related ROD document definition components.
-
record oriented data document definition (ROD
document definition)
- A description or layout of a proprietary
document, comprising loops, records, structures, and fields.
-
record oriented data field (ROD field)
- A single item of data, such as a purchase order number, in a record
oriented data (ROD) document definition. A ROD field corresponds to an EDI
data element in an EDI document definition.
-
record oriented data loop (ROD loop)
- A group of consecutive records and loops that repeat together in a ROD document
definition.
-
record oriented data record (ROD record)
- A group of logically related fields set up as a record in a ROD document
definition.
-
record oriented data structure (ROD structure)
- A group of related fields in a ROD document definition, such
as the fields making up the line item of an invoice. The record oriented data
(ROD) structure corresponds to an EDI composite data element in an EDI document
definition.
-
record-oriented file
- A file with
a record-oriented structure that is accessed record by record. This file structure
is typical of data sets on VM, MVS, and OS/400 systems. See also stream data file.
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record resource block (RRB)
-
record selection
- The process of selecting
particular records from a file and including the information from the records,
for example, in a report.
-
record separator
- In BSC, a control
character used to indicate the end of one record and the beginning of another.
-
record type
- The classification of
records in a file. Records of the same type have the same fields in the same
order. For program-described files, these records have record identification
codes; for externally described files, the records have the same record format
name.
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recover
- To rebuild data after it
has been damaged or destroyed.
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recoverability
- (1) The degree or extent
to which the system can be restored to an operational condition after a system
failure.
- (2) The ability of a system to continue processing without
loss of data when an unplanned interruption occurs.
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recoverable data
- Data with values
that persist through system shutdowns and failures. Changes made to recoverable
data are permanent regardless of system problems.
-
recoverable data set
- A data set that
can be recovered using commit, backout, or forward recovery processing. See
also commit, forward recovery, backout.
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recoverable in-doubt structure (RIS)
- In DBCTL, an area constructed for each unit of recovery when a failure occurs.
Each RIS is written to the IMS log. RIS contents include the recovery token,
the changed data records, and the identity of the data block that cannot be
accessed because of unresolved in-doubts.
-
recoverable resource
- (1) A resource that
can be modified only in accordance with sync point protocols.
- (2) See protected resource.
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recoverable resource management services (RRMS)
- The set of three system components that provide resource recovery
services in z/OS: resource recovery services (RRS), context services, and
registration services.
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recoverable service element (RSE)
- (1) A service element (IMS) that is backed up and that can initiate a takeover.
- (2) A set of DBCTL subsystem identifiers of equivalent DBCTL subsystems,
their associated job names, and the specific APPLIDs of the CICS systems that
will use them. RSEs are defined by CICS resource definition macros and are
held in the recoverable service table (RST). See also equivalent, recoverable service table.
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recoverable service table (RST)
- CICS control table used for IMS/ESA DBCTL support. The RST consists of recoverable
service elements (RSEs), which define the DBCTL subsystems to which each CICS
system can connect. See also equivalent, recoverable service element.
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recoverable status
- Any resource status
that can be recovered after a terminal logoff, a user signoff, or an IMS restart.
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recoverable transaction
- An IMS transaction
that is recovered in the event of a failure.
-
recovery
- (1) The process of re-creating
a database or table space that became unusable because of hardware failure,
software failure, or both. The process includes restoring a backup image and
can also include rolling database logs forward in time.
- (2) In Backup,
Recovery, and Media Services, the process of locating and restoring data in
the event of partial or total data destruction. The recovery service automatically
locates the correct media to be restored based on user-defined media management
and recovery requirements.
- (3) The process of returning the system
to a state from which operation can be resumed.
- (4) The restoration
of resources following an error.
- (5) The process of rebuilding data
after it has been damaged or destroyed, often by using a backup copy of the
data or by reapplying transactions recorded in a log.
- (6) The process
of restoring access to file system data when a failure has occurred. Recovery
can involve reconstructing data or providing alternative routing through a
different server.
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recovery authority
- The person or
persons who are authorized to recover IDs and to reissue new passwords to
end users.
-
recovery control data set (RECON data sets)
- A data set in which DBRC stores information about logging activity and
events that might affect the recovery of databases.
-
recovery domain
- A subset of nodes
in a cluster that are grouped together for a common purpose, such as rebuilding
databases after a system failure. A domain represents those nodes of the cluster
where cluster resource exists.
-
recovery event
- An event occurs when
acceptable performance (or availability) is regained after a violation. See
also violation event.
-
recovery-level tracking
- In an RSR
environment, a tracking IMS that does not track the databases or areas of
the active IMSs, but instead saves all database changes on tracked logs on
the tracking IMS until recovery or remote takeover is performed See also
database-level tracking.
-
recovery library
- The library containing
information related to recovery of database operations from system failures.
Named QRECOVERY.
-
recovery log
- (1) See database log.
- (2) In WebSphere MQ for z/OS, data sets containing
information needed to recover messages, queues, and the WebSphere MQ subsystem.
See also archive log, active
log.
- (3) A collection of records that describes the events that
occur during DB2 execution and indicates their sequence. The recorded information
is used for recovery in the event of a failure during DB2 execution.
-
recovery log data set (RLDS)
- A log
data set that contains only the log records that are required for database
recovery.
-
recovery manager
- (1) CICS resource recovery
mechanism that provides a CICS resource manager, for example file control,
with more flexibility than the DWE two-phase commit support for syncpoint
and backout processing.
- (2) A subcomponent that supplies coordination
services that control the interaction of DB2 resource managers during commit,
abort, checkpoint, and restart processes. The recovery manager also supports
the recovery mechanisms of other subsystems (for example, IMS) by acting as
a participant in the other subsystem's process for protecting data that has
reached a point of consistency.
- (3) A coordinator or a participant
(or both), in the execution of a two-phase commit, that can access a recovery
log that maintains the state of the logical unit of work and names the immediate
upstream coordinator and downstream participants.
-
recovery pending (RECP)
- The state
of a database or table space when it is restored from a backup. While the
database or table space is in this state, its data cannot be accessed.
-
recovery point
- In the CICS backup-while-open
facility, the latest point, on the CICS forward recovery log series for this
data set, from which forward recovery can start and restore any image copy
taken at that point to a consistent state. The recovery point is held as a
time that can be converted to a position on the forward recovery log.
-
recovery policy
- In Backup, Recovery,
and Media Services, a policy that defines the default controls and values
to be used in recovery operations.
-
recovery procedure
- An action performed
by the operator when an error message appears on the display screen. This
action usually permits the program to continue or permits the operator to
run the next job.
-
recovery-readiness-level database
- In an RSR environment, a database or area to which database changes are not
applied as they are received from the active subsystem, but instead are saved
on tracked logs on the tracking subsystem until recovery or remote takeover
is performed, or until the database's (or area's) readiness level is changed
to database readiness level. See also readiness level.
-
Recovery Resource Services attachment facility
(RRSAF)
- A DB2 subcomponent that uses Resource Recovery Services
to coordinate resource commitment between DB2 and all other resource managers
that also use RRS in a z/OS system. See also call attachment
facility.
-
recovery routine
- A routine that is
entered when an error occurs during the performance of an associated operation.
It isolates the error, assesses the extent of the error, and attempts to correct
the error and resume operation.
-
recovery system
- A system that is
used in place of a primary application system that is no longer available
for use. Data from the application system must be available for use on the
recovery system; data is usually made available through backup and recovery
techniques, or through various direct access storage device (DASD) copying
techniques, such as remote copy.
-
recovery termination manager (RTM)
- A program that handles all normal and abnormal termination of tasks by passing
control to a recovery routine associated with the terminating function.
-
recovery token
- (1) An identifier for
an element that is used in recovery (for example, NID or URID).
- (2) A 16-byte unique identifier that is created by CICS and passed to DBCTL for
each logical unit of work (LUW). See also pseudorecovery
token.
-
recovery volume
- The first volume
of a prime index if the Virtual Storage Access Method (VSAM) data set is a
key-sequenced cluster. If the VSAM data set is entry-sequenced, a recovery
volume is the first volume of the data set.
-
RECP
- See recovery
pending.
-
recurring wait time trigger
- A trigger
that is evaluated based on a period of time. For example, a recurring wait
time trigger can be evaluated every 30 minutes and fire if it detects that
a specific business situation has occurred.
-
recursion
- A programming technique
in which a program or routine calls itself to perform successive steps in
an operation, with each step using the output of the preceding step.
-
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.
-
recursion level
- The position of a
program in a call stack. The first occurrence of a program in a job has a
recursion level of 1, the second occurrence of the same program has a recursion
level of 2, and so on.
-
recursive
- Pertaining to a program
or routine that calls itself after each run until it is interrupted.
-
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 mutex
- A read/write lock
that is acquired again by the owning thread.
-
recursive procedure
- An active procedure
that can be called from within itself or from within another active procedure.
-
recursive program
- A program that
can call itself, or be called by another program, and repeat indefinitely
until a specified condition is met.
-
recursive query
- A fullselect that
uses a recursive common table expression.
-
recursive routine
- A routine that
can call itself or be called by another routine that it has called.
-
recycle process
- A DFSMShsm process
that, based on the percentage of valid data on a tape backup or a migration-level-2
volume, copies all valid data on the tape to a tape spill backup or migration-level-2
volume, omitting expired, deleted, or recalled data sets.
-
redeployment
- The process of synchronizing
a hard-disk content to its reference image strored in a hidden and protected
partition.
-
redeployment preload
- The process
of creating a reference image of a computer at the end of a deployment, and
saving this reference image into a protected redeployment partition. This
protected partition is invisible to the user and to the operating sytem.
-
redirect
- To divert data from a process
to a file or device to which it would not normally go.
-
redirected distribution
- A method
of software distribution that uses a file-distribution server.
-
redirection
- In a shell, a method
of associating files with the input or output of commands.
-
redirection URL
- A URL used in a URL
command to indicate the page that should be sent to the customer upon completion
of the command. See also shopping flow URL.
-
rediscovery
- A type of discovery in
which a program finds resources that were moved and updates the record of
their location, including the location of resources that were deleted. For
example, resources that were previously discovered, but are no longer found,
are deleted.
-
redo
- A state of a unit of recovery
that indicates that changes are to be reapplied to the disk media to ensure
data integrity.
-
REDO
- The DEDB process in the second
phase of a two-phase commit process if the chosen action is COMMIT. For DEDBs,
if phase two action is COMMIT, the changes are written to the database using
REDO, because the DEDB changes have only been made in main storage. If the
action is BACKOUT, no changes are required to the database because the updates
are still in main storage. The process applied is called UNDO. REDO is also
used to refer to the action required for committed DEDBs during emergency
restart of IMS, DL/I, or SQL/DS.
-
reduce
- To free up enough space such
that you can delete a volume from the database or recovery log. See also extend.
-
reduced instruction set computer (RISC)
- A computer that uses a small, simplified set of frequently used instructions
for rapid processing. See also complex instruction
set computer.
-
reduced-sign-on plug-in
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