e architecture's components, relationships and their respective types.
- A path over which data flows between the network and the receiving hardware (processor, memory, or storage).
- In X.25 communications, a means of two-way simultaneous transmissions across a data link, comprising associated send and receive channels. A logical channel can represent the path that data travels from its origin to the network or from the network to its destination.
- In a packet-switching data network, a path over which data flows between the network and the sending or receiving data terminal equipment.
logical channel subsystem (LCSS)
A channel subsystem structure that provides channel path and subchannel controls for configuring from one to four channel subsystem images. Each channel subsystem image can be configured with up to 256 channel paths, and each logical partition has access to one channel subsystem image.
logical character delete symbol
In VM, a special editing symbol, normally the AT (@) sign, that causes CP to delete it and the immediately preceding character from the input line. If many delete symbols are typed in consecutively, that same number of preceding characters are deleted from the input line. The value may be redefined or unassigned by the installation or user.
In a database, a pointer segment that establishes an access path between its physical parent and its logical parent. It is a physical child of its physical parent; it is a logical child of its logical parent.
A claim on a logical partition of a nonpartitioning index. See also claim.
logical control unit (LCU)
See control-unit image.
A database composed of one or more physical databases arranged in a hierarchical structure based on relationships among data segments. The structure of a logical database can be different from the physical structure of the data. See also physical database.
logical database record
In a database, a set of hierarchically related segments of one or more segment types. As viewed by the application program, the logical database record is always a hierarchic tree structure of segments. All of the segments that exist hierarchically dependent to a given root segment and that root segment. See also database record.
logical data group
A collection of data elements that gathers database system monitoring information for a specific scope of database activity. The snapshot monitor and event monitor each has its own sets of logical data groups. See also monitor element.
logical data model
The data model that captures the business definition of information assets by using the entity-relationship modeling approach. The logical data model consists of a set of related entities and their business associations. The logical data model can be represented graphically in the logical data model diagram. The logical data model contains logical entities, logical relationships, entity generalization hierarchies, and logical domains.
logical data stream (LDS)
In bidirectional text representation, a stream of data that is organized in a readable sequence. See also visual data stream.
A derivation from a physical document that can have additional service description metadata allocated to the derivation. See also logical model.
- A file for conducting input or output with a physical device.
- A file for mapping user I/O between virtual and real devices.
- A set of input or output operations for a physical or virtual device. For example, the Router logical device has logical device operations for creating a route and removing a route. Logical devices can be an abstraction of a physical device, such as a router, or virtual device, such as a software product.
- The facilities of a logical subsystem with which a host communicates when performing I/O operations to a single addressable unit over an I/O interface. The same logical device may be accessible over more than one I/O interface.
logical device component (LDC)
A subcomponent (for example, a printer or a console) configured with a 3601, 3770 batch, 3770, 3790 batch or LU Type4 terminal. Each subcomponent is ha