SQL/MP Glossary

Glossary
Compaq NonStop™ SQL/MP Glossary—429832-001
Glossary-3
browse access
browse access. An access option for transaction consistency that gives users immediate
access to data when a transaction in progress might be changing the data. With browse
access, a process does not acquire a lock on the data it accesses and does not test for
existing locks before reading data. Browse access can be specified only for reading data.
Of the access options, browse access provides the lowest consistency but the highest
concurrency. Contrast with repeatable access
and stable access.
c89. A command that invokes components of the C compilation system from the Open
System Services (OSS) environment. It can be used to perform any phase of a C
compilation, including compiling, binding, accelerating, and SQL-compiling (compiling
C programs that contain embedded SQL statements).
CASE expression. A conditional expression you can use to evaluate a set of conditions and
obtain a value based on the condition in the set that is true.
catalog. A set of tables containing descriptions of SQL objects, such as tables, indexes, and
views. Contrast with catalog table
and data dictionary. See also system catalog.
catalog format version. A version that indicates the physical structure of the catalog and the
oldest version of NonStop SQL/MP software that can read and write to the catalog. The
string is stored in the CATALOGFORMAT column of the VERSIONS catalog table.
Contrast with catalog version
.
catalog manager. The NonStop SQL/MP component that executes DDL statements and that
coordinates any catalog table updates with disk label updates to preserve consistency
between them.
catalog name. A name used to identify a catalog. The catalog name is the same as the name
of the subvolume that contains the catalog.
catalog table. One of the tables in an SQL catalog; each table describes SQL objects (tables,
views, indexes, collations, and constraints). The CATALOGS table in the system catalog
describes the SQL catalogs on the node.
catalog version. A version that indicates the newest version of SQL objects that can be
registered in a user catalog. The version number is stored in the CATALOGVERSION
column of the VERSIONS catalog table. Contrast with catalog format version
. See also
object version
and system catalog version.
CATALOGS table. A directory table in the system catalog that contains one entry for each
catalog on the node. The table is stored in a file named SQL.CATALOGS.
character data type. A data type for data composed of single-byte or multibyte characters,
stored as either a fixed-length or variable-length character string. Contrast with numeric
data type.
character expression. A column name, literal, function, host variable, or parameter that has
a character data type.