SQL/MP Glossary

Glossary
Compaq NonStop™ SQL/MP Glossary—429832-001
Glossary-22
physical file attribute
physical file attribute. See file attribute.
physical primary key. The unique value that identifies the rows in a table and determines the
order in which rows are stored in a file. Within a table, each row’s primary key value
must be unique. The physical primary key is derived from a table’s definition. Contrast
with index
. See also clustering key, index, primary key, system-defined primary key,
and user-defined primary key.
PIN (process identification number). An unsigned integer that identifies a process in a
processor module.
precision. A positive integer that represents the number of significant digits.
predicate. An element in a search condition that returns a value of true, false, or unknown;
for example, a predicate can compare two values or determine if a value exists. See also
search condition
.
predicate set. A series of predicates that comprises only ANDs, BETWEENs, and IN
predicates.
preprocessor. See SQL preprocessor
.
primary key. One or more columns whose values uniquely identify the rows of a table and
determine the order in which the rows are stored. The primary key of a table stored in a
key-sequenced file is defined by the user (PRIMARY KEY clause of the CREATE
TABLE statement), by the user and the NonStop SQL/MP system (CLUSTERING KEY
clause of the CREATE TABLE statement plus the SYSKEY column), or by the system
(SYSKEY column). The primary key of a table stored in a relative or entry-sequenced
file is defined by the system. The primary key also serves as the physical primary key
for the file or files containing the table. Contrast with index
. See also clustering key,
SYSKEY column, system-defined primary key, and user-defined primary key.
primary partition. The partition of a partitioned table or index that contains the lowest set of
key values if the collating sequence is ascending, or the highest set of key values if the
collating sequence is descending.
print item. An item to print (or display) in a report. A print item can be a column identifier,
literal, arithmetic expression, or report clause such as TAB or CONCAT.
print list. A list of print items specified in a detail line, title, footing, or report clause.
print position. The space occupied by one single-byte character.
process. An executing object program, including code and data spaces.
process accessor ID. See PAID (process accessor ID)
.
process context. The collection of attributes that define the current default catalog, node,
volume, subvolume, security, message file, PARAM settings, and DEFINEs for a
process.