SQL/MX 3.2 Management Manual (H06.25+, J06.14+)

Table Of Contents
names used follow the preceding rules. If you do not specify the Guardian file and subvolume
names, NonStop SQL/MX automatically generates those names. To avoid incidentally
meaningful but undesirable names (for example, ZSDHELL0.SMARTY00), vowels and the
digit zero are never used in generated portions of names. While user-supplied names must
conform to the other Guardian naming rules, they can contain vowels and the digit zero.
Using Catalog References in an SQL/MX Distributed Database
This subsection describes how to manage catalog references in an SQL/MX Release 3.x
network-distributed database.
System Schema Tables
A record of the catalogs that are registered on a node is maintained in the system schema on the
node. The system schema name, NONSTOP_SQLMX_nodename.SYSTEM_SCHEMA, enables
each node in an Expand network to have a unique ANSI name for its system schema. The metadata
tables in the system schema are called system schema tables.
Catalog names that begin with NONSTOP_SQLMX_ are reserved for use by NonStop SQL/MX
and cannot be created or registered by users.
Table 19 (page 268) describes the five system schema tables and their roles in catalog references
for SQL/MX Release 3.x.
Table 19 System Schema Tables
DescriptionTable
Represents catalog visibility on a node. It contains one row for each catalog that is
visible on the node, with an indication of the schema replication rule (automatic or
CATSYS
manual) for the catalog. Use the CATSYS table to verify whether a catalog is visible
on a node.
Represents catalog references. The node where a given catalog is created has the
only automatic catalog reference for that catalog. That node’s table has a row for
CAT_REFERENCES
each catalog reference for the catalog. Other nodes for which the catalog is
registered have empty manual catalog references for that catalog. Those nodes
tables have rows only for the automatic catalog reference and the local reference.
The CAT_REFERENCES table locates a node with an automatic catalog reference
from nodes where the local reference is empty (manual).
Represents schema replication. Because SQL/MX Release 3.x does not support
schema replication, schemas for a catalog are identified only on the automatic
SCHEMA_REPLICAS
catalog reference node. DDL and utility operations use the SCHEMA_REPLICAS
table to determine what nodes need to be updated as the result of the operation.
Represents the schema on a node. It contains one row for every schema that is
visible on the node. If a catalog reference for a catalog exists on a node and a
SCHEMATA
schema name for a schema in that catalog is not found in the SCHEMATA table on
that node, that schema does not exist.
Catalog Reference Guidelines for SQL/MX Release 3.x
The node where a catalog is created contains the object metadata for all database objects
in that catalog and is the only automatic catalog reference for that catalog.
The object metadata for a catalog, including schema metadata and metadata definitions,
cannot be replicated from the automatic reference node to other nodes.
Catalog registration metadata can be replicated to other nodes. Use the REGISTER CATALOG
command from the automatic catalog reference node to create empty catalog references on
other nodes in the distributed database.
268 Managing an SQL/MX Distributed Database