Availability Guide for Change Management

Glossary
Availability Guide for Change Management–125506
Glossary-4
entry-sequenced file
entry-sequenced file. A file in which each new record is stored at the end of the file in
chronological sequence and whose primary key is a system-generated record address.
environmental outage class. An outage class that includes failures in power, cooling,
network connections, natural disasters (earthquake, flood), terrorism, and accidents.
Expand. Tandem’s NonStop network that extends the concept of fault-tolerant operation to
networks of geographically distributed NonStop systems. If the network is properly
designed, communications paths are constantly available, even in the event of a single
line or component failure.
fault tolerance. The ability of a Tandem NonStop system to continue processing despite the
failure of any single software or hardware component within the system.
file. A logical construct subject to operations such as reading and writing. The term file is
most commonly used to refer to data stored on a disk, but on the NonStop system,
processes, devices, and various other entities are also defined as files.
file system. A set of system procedures that run as part of a user’s process and send messages
to other processes, such as input/output (I/O) processes.
File Utility Program (FUP). A Tandem product that allows users to create, copy, purge, and
otherwise manipulate disk files interactively.
firmware. A type of microcode that resides on certain circuit boards and devices. The two
principle types of microcode are firmware or bootstrap code, sometimes called “boot
PROM code,” and operational microcode for downloadable controllers. Boot code for a
device starts or boots the device and may also contain power-on diagnostics. During a
system load or while a controller is being loaded, operational microcode is downloaded
from storage into volatile memory.
graphical user interface (GUI). A type of screen interface that typically includes pull-down
menus, icons, dialog boxes, and online help.
host language. Any programming language whose statements can be combined with SQL
statements in the same source program.
host program. A source program that contains both host language statements and embedded
SQL statements.
index. An alternate access path to a table that differs from the inherent access path (or
primary key) defined for the table at creation time. An SQL index, stored in a file,
includes columns for the primary key and the alternate key.
input/output (I/O) process. A system process that manages communications with I/O
devices (such as disks and printers) and communications lines. An I/O process pair
logically “owns” one or more I/O devices or communications lines. I/O processes are
the system processes that make up a communications subsystem.