L

layout

The arrangement of record blocks, sets, and indexes in a CA IDMS Schema Mapper data structure diagram.

LID

A 4-byte value that locally identifies the work done by a transaction branch. A single LID value is carried in BFOR, AFTR, COMT, ENDJ, and ABRT journal records to distinguish the work done by one branch from that of another. Multiple LID values can occur in the CKPT, DCOM, and DBAK records.

line

1) A communication line. 2) An IDD entity type used to document a method of communication.

line drivers

The software components that communicate with the access methods in use to move data between main storage and teleprocessing I/O devices.

line index

The item that identifies the location of a record occurrence on a database page. A database page contains one line index for every record occurrence on that page.

line mode

In DC/UCF programs, line-by-line transfer of data to and from a program.

link

In CA IDMS/DB and CA IDMS/DC programming, the process of loading a program or dialog and passing control to it.

linkage options

In CA IDMS/DB, options that allow the user to specify the types of pointers (next, prior, and/or owner) to be used in relating member and owner occurrences of a set.

linked constraint

A referential constraint in which CA IDMS/DB maintains a physical linkage between the rows in the referenced and referencing tables. See also unlinked constraint.

linked relationship

A relationship in which related entity occurrences are linked to one another through embedded pointers. Types of linked relationships are: chained or indexed. See also unlinked relationship.

literal field

In the Mapping Facility, a map field that displays a predefined literal string to be displayed.

LKG

See lock grant control block (LKG)

LKS

See lock session block (LKS).

LKW

See lock wait block (LKW).

load area

The DDLDCLOD or DDLCATLOD areas of the data dictionary in which load modules are stored. See also DDLDCLOD area, DDLCATLOD area, load module.

load list

A path used by the DC/UCF system when searching for programs to load. A load list can include both load libraries and data dictionaries. You define load lists during DC/UCF system generation.

load module

1) A program unit in executable code that can be loaded into main storage for execution. CA IDMS products use load modules stored in the load areas (DDLDCLOD or DDLCATLOD) of the dictionary or in a load library. 2) An IDD entity type used to define a load module. See also load area.

LOAD utility statement

For an SQL-defined database, the utility that loads data.

local mode

A CA IDMS/DB mode of operation in which a batch program uses a dedicated copy of the DBMS to access the database. In local mode, only one application program can update the database at any given time. See also central version.

local node

In a DC/UCF communications network, the DC/UCF system that controls the terminal you are using. In batch mode, the local node is the DC/UCF system with which your program first establishes communication. This term is a synonym for host node.

local response

In CA ADS, the type of response that is valid only when specifically associated with a function. The concept of a local response applies specifically at application definition time. The opposite of a local response is a global response.

local task

In a DC/UCF communications network, a DC/UCF task that is requested and executed at the host node. The resulting database I/O can be performed by either the host node or target node.

local transaction

A transaction in which changes are made to resources controlled by a single resource manager.

location mode

The manner in which a record occurrence is physically located in an area of the database. The three available location modes are CALC, DIRECT, and VIA.

lock acquisition mode

For SQL sessions, the mode that determines when area locks are acquired. Preclaim mode places locks on all areas that specify PRECLAIM when the first statement that requires access to the database is executed. Incremental mode delays placing a lock on an area until the first statement that requires access to the area is executed. See also preclaim lock acquisition mode, incremental lock acquisition mode.

LOCK AREA utility statement

The utility that places a physical area lock on an area or all areas in a database segment.

lock grant control block (LKG)

The control block that identifies each resource in use by a task. All LKGs for the same resource are chained together so that all tasks sharing the resource can be identified.

lock mode

A mode associated with each logical lock that determines whether the lock conflicts with other locks already held on the resource and with locks subsequently requested by other transactions. See also share lock mode, exclusive lock mode, null-lock mode, intent lock.

lock session block (LKS)

The control block that associates locks managed by the lock manager with the user session requesting those locks. The LKS for a task that is waiting on a lock managed by the lock manager is chained to the LKW created to represent the wait.

lock wait block (LKW)

The control block that indicates a task is waiting for a database resource. All LKWs for the same resource are chained together so that all tasks waiting on the resource can be identified.

locking

In CA IDMS/DB, a facility that maintains the integrity of the database by restricting access by a transaction to records or areas that are currently in use by another transaction.

LOCKMON command

A system-defined task which you can use to display and react to locks being held for an area or by a terminal. You can also use Lock Monitor to free locks so that you can change states for an area.

log

The runtime repository for DC/UCF system messages, snap dumps, trace information, and statistics. The log can be assigned either to the DDLDCLOG area or to a sequential disk or tape file. See also DDLDCLOG area, log file.

log area

See DDLDCLOG area.

log file

A sequential disk or tape file defined for use as the DC/UCF system log. DC/UCF writes the system log to a sequential file or to the DDLDCLOG area, depending on the system-generation specification. CA OLQ Batch and CA ADS Batch users can specify their own sequential log files for use at execution time. See also log.

log service driver

The DC/UCF task that writes records to the CA IDMS/DC log area. Log service drivers also open the log area, initialize the CA IDMS/DC log work area, and acquire log buffers at system startup.

logical area lock

A lock used by the central version to control concurrent access to areas by database transactions running under the central version. Logical area locks are derived from the mode in which an area is readied. See also physical area lock.

logical database design

See logical model.

logical model

A logical mapping of data and data relationships, together with integrity rules, that represents the inherent structure of the data relative to a given set of business functions. Typically, the logical model is documented with the aid of data flow diagrams representing the known set of all corporate functions. The logical model is not application dependent; it represents all data entities and their relationships.

logical network

A combination of databases and application programs that handle an organization's information and processing requirements. See also physical network.

logical operators

The operators AND, OR, and NOT. These operators can be used in selection criteria to help specify the rows to be accessed from a data table.

logical record

One or more database records presented to the application program as a single record. Logical records provide access to multiple database records by a single request. The use of logical records is supported through the Logical Record Facility.

Logical Record Facility (LRF)

The software component that simplifies application programming by allowing the database administrator to predefine logical records and the processing sequences necessary to access them.

logical terminal

1) DC/UCF's view of the events associated with a particular physical terminal. The logical terminal is used by DC/UCF to communicate with the physical terminal. At runtime, the terminal operator's signon information (for example, password, and security codes), the executing task, and resources are associated with the logical terminal. A logical terminal is defined by the LTERM statement at system generation. 2) An IDD entity type used to document the logical terminals in an online environment.

logical terminal element (LTE)

The control block used by DC/UCF to manage and maintain the resources associated with a particular logical terminal.

logical-record element

A database record that forms part of a logical record.

logical-record occurrence

The data returned in response to a logical-record request. A logical-record occurrence is composed of one occurrence of each database record that makes up the logical record.

logical-record request

A database access function issued by an application program to request LRF services. The four logical-record functions are OBTAIN, MODIFY, STORE, and ERASE.

logical-record request control (LRC) block

The control block through which LRF communicates with the program requesting logical-record services.

logically deleted record

A record flagged for deletion but not yet physically deleted from the database. CA IDMS/DB physically deletes the record only after it has been disconnected from all sets of which it is a member.

logically deleted user/group

In centralized security, a user or group flagged for deletion but not yet physically deleted from the user catalog. The security facility physically deletes the user or group when you execute the SDEL task in each system of the security domain and against each dictionary in the system that contains the security definitions.

longterm lock

A shared or exclusive record lock that is maintained across transactions. See also locking, notify lock, record lock.

LOOK command

LOOK is a system-defined task that allows you to look at the contents of selected load modules. See also IDMSLOOK.

LRC block

See logical-record request control (LRC) block.

LRF

See Logical Record Facility (LRF).

LTE

See logical terminal element (LTE).

LTERM

See logical terminal.