SQL/MP Installation and Management Guide

The SQL/MP Database Management Environment
HP NonStop SQL/MP Installation and Management Guide—523353-004
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Multiple Character Sets
For each table, you can define one or more integrity constraints that the disk process
checks before inserting a row into the table. Each constraint is an SQL object. If a row
does not satisfy a condition specified in a constraint, the disk process does not insert
the row. Likewise, update values for existing rows must satisfy all constraints on the
table.
Concurrency control for database access provides different degrees of database
consistency to meet different needs: browse access, stable access, and repeatable
access. These access modes are maintained by shared or exclusive locks on rows,
sets of rows, partitions, and tables.
Multiple Character Sets
SQL/MP supports multiple character sets with the CHARACTER, PIC X, and
VARCHAR data types and the CHARACTER SET clause. In addition, the NATIONAL
CHARACTER data type supports double-byte character sets.
DEFINEs
A DEFINE is a named set of attributes and associated values stored in the process file
segment (PFS) of a running process. You simplify the SQL/MP environment by using
logical DEFINE names in commands, in OBEY command files, and in programs. You
can have the names apply to other SQL objects just by changing the DEFINEs.
You can use a DEFINE name to specify a subvolume, catalog, table, view, or index in
SQL/MP statements and commands and in host application programs. Typically, you
use a DEFINE to establish a one-to-one mapping between a logical name and a
physical name. For more information, see Using DEFINEs on page 10-30.
Database Security
Authorization to operate on SQL/MP tables, indexes, views, collations, and SQL
programs that run in the Guardian environment is maintained by Guardian security and
checked by SQL/MP. You can use the Safeguard security management facility for
additional security protection for volumes and subvolumes containing SQL objects and
for individual SQL programs stored in Guardian files. For more information, see
Security Guidelines on page 4-2.
Authorization for SQL programs stored in the OSS environment is maintained by the
OSS security subsystem.