B – glossary entries

back-end processor
A z/TPF processor that receives input messages routed from a front-end processor; that is, a back-end processor has no communication support in it. A back-end processor provides application program processing and database management functions, usually on a large database. In a loosely coupled complex, multiple back-end processors share a common database. Contrast with front-end processor.
backup record
See duplicate record.
bag collection
A type of collection with unordered, nonunique elements. There is no access by key.
BAL shared object (BSO)
A type of of shared object consisting of one or more objects created by assembling z/TPF E-type basic assembler language (BAL) programs. See C shared object (CSO) and shared object.
band number
In a FARF3 file address, a unique random value between 0 and 4095 that is associated with a fixed file record type.
base FACE table (FCTB)
A FCTB loaded by using the image loader, general file loader, or an alternate FCTB that has been accepted by using the ZFCTB ACCEPT or ZODBR ACCEPT commands. See also alternate FACE table (FCTB), alternate face table (FCTB) loader, general file loader, and image loader.
basic subsystem (BSS)
The primary subsystem that contains the control program and all support programs necessary for a stand-alone z/TPF system. All system-related tasks, including I/O processing, are processed by the BSS.
BBT
Buffer block table.
binary large object (BLOB) collection
A type of collection with ordered, nonunique elements that are 1 byte each. There is no access by key. Elements are ordered by ascending relative byte address (RBA). Elements cannot be inserted or deleted before an existing element. Operations can be performed in the range from 1 to 32000 bytes at a time. Synonymous with byteArray collection.
bind process
A process in which a relational database management system transforms the specification of an Structured Query Language (SQL) statement into a sequence of internal operations to optimize data retrieval.
BLOB collection
Binary large object.
block cipher
An encryption method that operates on data in groups rather than bytes. See also bulk cipher.
blocked records
See blocked tape.
blocked tape
A tape recorded with nonspanned variable block length (format-VB) blocks. The logical records on the tape are usually referred to as blocked records. A tape of physical records that can be composed of several contiguous logical records or parts of logical records. Physically, the blocked tape is read one record at a time; logically, the z/TPF system manages the blocked tape record by record. Contrast with unblocked tape.
blocking mode
A program may be suspended indefinitely until data requested using a socket API function, for example read or write, is available. See nonblocking mode.
bracketed TOD clock
An 8-byte format for the time-of-day (TOD) clock that is used to migrate to the extended TOD clock. Bracketed means that TOD clock values are grouped into brackets, which are continuous ranges of timestamps. The leftmost bit of a TOD clock value determines which bracket the value belongs to. See also extended TOD clock and epoch TOD clock.
breakpoint
When a C or C++ program is compiled using the -mtpf-trace option of a z/TPF-supported compiler, the computer generates a breakpoint, which is a Test under Mask (TM) instruction followed by a Branch Not Zero (BNZ) instruction. An entry breakpoint is generated at the beginning of a function. A return breakpoint is generated at the completion of a function.
browse cursor
In message queuing, an indicator that is used when browsing a queue to identify the message that is next in sequence.
browse support
For z/TPF collection support (z/TPFCS), support that allows z/TPF persisten collection classes, methods, and collections to be located, displayed, interrogated, dumped, and validated.
For message queuing, support that allows messages on a queue to be viewed without necessarily removing them from the queue.
BSN
Byte sequence number.
BSO
BAL shared object.
BSS
Basic subsystem.
BSS resident
An application or resource that may be allocated only to the basic subsystem.
buffer block table (BBT)
A table containing the addresses of all 4 KB working storage blocks currently in use as part of a buffer for a tape in blocked mode.
build
The process that creates one or more z/TPF system components, such as the control program (CP), keypoints, and real-time programs (both system programs and user programs) to be loaded to the system.
bulk cipher
A symmetric encryption algorithm that is used to encrypt and decrypt large amounts of data. There are two types of bulk ciphers: stream ciphers and block ciphers. See also stream cipher and block cipher.
business event
An occurrence of significance to a business. See also event message business event, signal event, and data event.
business event dispatch adapter
A transport mechanism that sends data to the event consumer. The business event dispatch adapter is defined in a business event dispatch adapter specification.
business event dispatch adapter specification
An XML file that contains the deployment descriptor for a single business event dispatch adapter.
business event dispatch queue
A IBM® MQ queue where business event information is placed temporarily. A separate program removes the item from this queue and sends the item to the event consumer.
business event specification
An XML file that contains the deployment descriptor for a single business event.
byteArray collection
A type of collection with ordered, nonunique elements that are 1 byte each. There is no access by key. Elements are ordered by ascending relative byte address (RBA). Elements cannot be inserted or deleted before an existing element. Operations can be performed in the range from 1 to 32000 bytes at a time. Synonymous with binary large object (BLOB) collection.
byte sequence number (BSN)
A number in the transport header (THDR) of a network layer packet (NLP) that indicates the order in which data was transmitted by the sending node.