B

back end

1) Under UCF, the portion of the system that performs DC/UCF tasks. The back end receives control and data from the CA IDMS UCF front end, which can be CA IDMS/DC or any of the other supported TP monitors. The back end then invokes the specified task and, when the task is finished, returns control and passes data back to the CA IDMS UCF front end. 2) The CA IDMS central version that receives and processes a remote database request.

backlog

In the context of TCP/IP, a value that limits the maximum number of pending connections.

backout operation

The process of reversing the effects of a transaction. During a backout operation, all database changes made during the life of the transaction are rolled back, and one or more of the following journal checkpoints are written: ABRT, DBAK. See also rollback.

backup

A database maintenance operation that produces a copy of the database that can be used to restore lost data.

BACKUP utility statement

The backup utility. BACKUP copies one or more areas or files in a database to a backup file, which can be used later as input for a restore operation.

base table

A data table which is not derived from other tables. See also data table, view.

basic mode

1) In CA ADS, the mode of operation when the runtime system is executing an application not created with the application compiler. The movement between dialogs is determined solely by the inter-dialog commands that have been coded in the dialog premap and response process modules. 2) In DML programming, the mode of operation in which data and device control characters are transferred by the application program according to the type of terminal in use. See also application mode.

Batch Command Facility (IDMSBCF)

The CA IDMS tool you use to submit Command Facility statements as part of a batch job stream. See also Command Facility.

batch control event

In CA ADS Batch, batch conditions, such as EOF and I/O error condition, that can occur at runtime during file input operations. To cause special processing to occur based on one of these events, either associate a dialog response process with the events or test for the event in dialog process statements.

batch Mapping Facility (RHDCMAP1)

The batch component of the Mapping Facility. Use this component to define, generate, modify, and delete maps in a batch environment.

batch program

A program that executes in its own region or partition. A CA IDMS/DB batch application program can run either in local mode or under the central version. See also online program.

batch simulation

The simulation of the DC/UCF 3270 input and output in batch mode. This capability allows you to simulate either single or multiple terminal DC/UCF configurations in a single batch simulator job.

before image

See BFOR journal record.

below the line

Under systems that support extended addressing, using storage addresses lower than 16 MB. DC/UCF program, reentrant, and storage pools can reside either below or above the line. See also above the line.

BFOR journal record

The journal record that contains the image of a database record before it has been updated.

BGIN checkpoint

The checkpoint that marks the start of local work done by a transaction branch. This checkpoint is written to the journal file when the first update occurs or when a database transaction is initiated if JOURNAL RETRIEVAL is specified at system generation.

BID

See transaction branch identifier.

bill-of-materials structure

A many-to-many relationship among record occurrences of the same type. A bill-of-materials structure in the database enables explosion and implosion of the occurrence relationships for that record. See also nested structure, self-referencing relationship.

BIND

1) The database access function that initiates a run unit. The BIND function establishes addressability in variable storage to the IDMS communications block, to the record types, and optionally to procedure control information. 2) A DML command that establishes addressability in variable storage to the map request block (MRB) and to the record types used by the map.

block

1) In a general database environment, a physical unit of storage in a file. A block corresponds to a VSAM control interval or a BDAM record. 2) In a CA IDMS DDS environment, a physical unit of data that can be transmitted from one DDS node to another.

boolean selection criteria

See selection criteria.

border

Under CA IDMS Schema Mapper, the number of character spaces around the perimeter of each record block in the data structure diagram. A minimum border of two character spaces is needed for set connections and arrows; the maximum is 50 character spaces. A two-character border puts at least four character spaces between any two record blocks.

branch identifier

See transaction branch identifier.

breakpoint

A temporary program interruption set by the online debugger. When a breakpoint is reached, control is passed from DC/UCF to the programmer.

buffer

A location in memory used at runtime to hold database or journal pages. Buffers compensate for speed differences between the CPU and I/O devices. You define database and journal buffers in the DMCL module by using physical DDL statements. See also database buffer, journal buffer, record buffer, buffer page, buffer pool.

buffer page

A buffer that is capable of holding a single database or journal page.

buffer pool

A collection of buffer pages capable of holding database or journal pages.

buffer utilization ratio

The ratio of pages requested to pages read by CA IDMS/DB. The ratio measures the effectiveness of buffer-pool size and the database design.

BUILD utility statement

For an SQL-defined database, the utility that builds indexes and referential constraints linked through an index on tables that are being loaded with a phased or stepped load

builder code

In IDD, a single-character code that is stored with an entity occurrence. This code indicates the CA IDMS component that created or owns the entity-occurrence definition.

built-in function

In CA ADS and CA OLQ, a routine that performs one of a variety of predefined string, arithmetic, date conversion, and trigonometric operations. You can use built-in functions when coding expressions in process code, selection criteria, and column computations.

built-in table

For maps, an editor code table that is defined in and only available to a specific element in the data dictionary. See also standalone table.

bulk external request unit

An external request unit that does not use a 3270-type device for input; rather it uses bulk data transfer. See also external request unit (ERU).

bulk fetch

In SQL programming, a FETCH statement that retrieves multiple rows from a cursor into a host variable array.

bulk insert

In SQL programming, an INSERT statement that adds multiple rows in a host variable array to a table in the database.

bulk processing

A CA IDMS/DB extension to ANSI-standard SQL that allows the program to select, fetch, or insert a group of rows using a host variable array.

bulk PTERM

In a DC/UCF system definition, a physical terminal device type that designates bulk data transfer. You define a bulk PTERM on the UCFLINE statement for each external application that will concurrently request data services from the DC/UCF system.

bulk select

In SQL programming, a SELECT statement that retrieves multiple rows from table(s) in the database into a host variable array.