SQL/MX 3.2.1 Management Manual (H06.26+, J06.15+)

Parallel index maintenance reduces the effect of multiple indexes on performance. Each index on
a table is automatically updated whenever a row is inserted into the table and whenever a value
is updated in any key column of the index. Multiple indexes on a table can be updated in parallel
by different disk processes or by the same disk process servicing multiple requests.
Indexes are loaded in parallel. Parallel index loading speeds the loading of a partitioned index
by loading all partitions at the same time.
Parallel sorting is performed by the executor server processes (ESPs).
Parallel input-output operations are performed on multiple partitions by different disk processes. A
single disk process can also perform parallel I/O by buffering operations in cache.
High Availability
These SQL/MX features help to ensure high availability for databases:
• Online dumps using the TMFCOM DUMP FILES command, with complete support for TMF file
recovery to recover a database in case of a disaster.
• Online database reorganization capabilities such as online partition moving, partition splitting,
and table and index row redistribution with concurrent read and update capability. For more
information, see “Reorganizing SQL/MX Tables and Maintaining Data” (page 178).
• Parallel table reorganization (using FUP RELOAD) and index loads (using POPULATE INDEX)
to reduce the time required to load the object.
• Automatic recompilation, which eliminates the need to terminate program execution when
changes in database structure or the environment make rebinding necessary.
• The ability to defer name resolution in SQL/MX statements until execution time.
Naming Database Objects
ANSI Logical Names
Names for SQL/MX objects are organized hierarchically. Database objects exist in schemas,
which are themselves contained in catalogs. Catalogs are collections of schemas. Schema names
must be unique within a given catalog.
You name tables, views, and other SQL/MX objects by using a three-part ANSI logical name:
catalog-name.schema-name.object-name
In this three-part name, catalog-name is the name of the catalog, schema-name is the name
of the schema, and object-name is the simple name of the object. Each of the parts is an SQL
identifier.
NonStop SQL/MX automatically qualifies an object name with the current default catalog and
schema name unless you explicitly specify catalog and schema names with the object name. These
terminology guidelines apply to ANSI names:
• A fully qualified or three-part ANSI name uses all three of its parts
(catalog-name.schema-name.object-name).
• A two-part ANSI name omits the catalog name (schema-name.object-name).
• A one-part or simple ANSI name omits the catalog and schema names (object-name).
The two-part name schema-name.object name is qualified implicitly by the current default
catalog. The one-part name object-name is qualified implicitly by the default schema and
catalog.
For more information, see the SQL/MX Reference Manual.
22 Introduction to SQL/MX Database Management