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

Managing a Network-Distributed SQL/MX Database
You can distribute an SQL/MX database—and the applications that access it—across nodes in
an Expand network. The database should be distributed in a way that provides a high degree of
transparency to applications and users while maintaining high performance and availability.
NOTE: For more information about managing a network-distributed SQL/MP database, see the
SQL/MP Installation and Management Guide.
An SQL/MX database or application can be distributed over a network of nodes in several ways:
• Tables or indexes are partitioned on disk volumes located on two or more nodes.
• Tables, indexes, views, or programs reside on two or more nodes.
• A local view, referential integrity constraint, or trigger references a remote table.
• Local applications access remote tables or use a remote access path.
• Remote programs access local tables, views, or indexes.
The goals for managing a network-distributed database are:
• To share data efficiently among users located remotely from one another.
• To enable local identity and control while sharing information.
• To eliminate duplication of data.
• To increase local computing power by the aggregate total of the computing power of the
network.
SQL/MX Distributed Database Features
For SQL/MX Release 3.2, you can:
• Register a user catalog on nodes other than the node where the catalog was created. The
object metadata for the catalog remains on the original node. Each registered node then can
locate the object metadata for that catalog. The catalog is “visible” on those nodes. For more
information, see the “Creating, Registering, and Unregistering Catalog References” (page 278).
• Execute statements and commands that operate on database objects in catalogs that are
visible from the node where the statement or command is executed.
• Distribute database objects to nodes where the objects’ catalogs are visible.
Database distribution is largely transparent to users of NonStop SQL/MX. Most of its features are
implemented at levels that make transparency possible. These features include:
• “Versioning Capabilities” (page 268)
• “User Data Distribution” (page 268)
• “Catalog Reference” (page 268)
• “ANSI Name Lookup” (page 268)
• “Visibility Rules” (page 269)
• “Transparency” (page 269)
• “Security Guidelines” (page 269)
• “Local Autonomy” (page 270)
Managing a Network-Distributed SQL/MX Database 267