IBM DB2 Manual page 571

CICS or IMS environments can run under
the TSO attachment facility.
typed parameter marker
A parameter marker that is specified
along with its target data type. It has the
general form:
CAST(? AS data-type)
type 2 indexes
Indexes that are created on a release of
DB2 after Version 7 or that are specified
as type 2 indexes in Version 4 or later.
UCS-2 Universal Character Set, coded in 2 octets,
which means that characters are
represented in 16-bits per character.
UDF See user-defined function.
UDT User-defined data type. In DB2 for z/OS,
the term distinct type is used instead of
user-defined data type. See distinct type.
uncommitted read (UR)
The isolation level that allows an
application to read uncommitted data. See
also cursor stability, read stability, and
repeatable read.
underlying view
The view on which another view is
directly or indirectly defined.
undo A state of a unit of recovery that indicates
that the changes that the unit of recovery
made to recoverable DB2 resources must
be backed out.
Unicode
A standard that parallels the ISO-10646
standard. Several implementations of the
Unicode standard exist, all of which have
the ability to represent a large percentage
of the characters that are contained in the
many scripts that are used throughout the
world.
| union An SQL operation that involves the
UNION set operator, which combines the
|
| results of two SELECT statements. Unions
| are often used to merge lists of values
that are obtained from two tables.
|
unique constraint
An SQL rule that no two values in a
primary key, or in the key of a unique
index, can be the same.
unique index
An index that ensures that no identical
key values are stored in a column or a set
of columns in a table.
unit of recovery (UOR)
A recoverable sequence of operations
within a single resource manager, such as
an instance of DB2. Contrast with unit of
work.
unit of work (UOW)
A recoverable sequence of operations
within an application process. At any
time, an application process is a single
unit of work, but the life of an application
process can involve many units of work
as a result of commit or rollback
operations. In a multisite update
operation, a single unit of work can
include several units of recovery. Contrast
with unit of recovery.
| universal table space
A table space that is both segmented and
|
partitioned. Contrast with partitioned
|
| table space, segmented table space,
partition-by-growth table space, and
|
range-partitioned table space.
|
unlock
The act of releasing an object or system
resource that was previously locked and
returning it to general availability within
DB2.
untyped parameter marker
A parameter marker that is specified
without its target data type. It has the
form of a single question mark (?).
updatability
The ability of a cursor to perform
positioned updates and deletes. The
updatability of a cursor can be influenced
by the SELECT statement and the cursor
sensitivity option that is specified on the
DECLARE CURSOR statement.
update hole
The location on which a cursor is
positioned when a row in a result table is
fetched again and the new values no
longer satisfy the search condition. See
also delete hole.
update trigger
A trigger that is defined with the
triggering SQL operation update.
UR See uncommitted read.
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Glossary