SQL/MX 2.x Installation and Management Guide (H06.10+, J06.03+)

Creating an SQL/MX Database
HP NonStop SQL/MX Installation and Management Guide—544536-007
7-6
Correcting File Name Problems
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index-definition
One use of the schema subvolume is to identify all Guardian files in an schema for use
with Guardian-based commands for TMF, RDF, and other subsystems. Unless you use
the REPEAT USE ALLOWED clause of CREATE SCHEMA, NonStop SQL/MX
prevents you from specifying a subvolume name that is already in use by another
schema. If you use this clause, you will receive a warning and the operation will
succeed. Using REPEAT USE ALLOWED is recommended only when creating an
RDF backup database.
If you do reuse a schema subvolume, a Guardian wild card of the form
\system.$*.subvolume.* identifies the physical files from all schemas that are
using this subvolume name. This might affect your future ability to refer only to objects
in specific schemas when issuing commands to TMF or RDF.
The subvolume name must conform to the rules for schema subvolumes described in
SQL/MX Subvolume Naming Guidelines on page 7-3. Otherwise, an error is
generated.
This example creates a schema with a subvolume name of ZSDABCDE:
CREATE SCHEMA sch2 AUTHORIZATION jsmith LOCATION ZSDABCDE;
This example creates a schema with a subvolume name of ZSDSCHEM:
CREATE SCHEMA myschema LOCATION ZSDSCHEM;
For more information about the CREATE SCHEMA statement, see the SQL/MX
Reference Manual.
Correcting File Name Problems
When a table or index is created with precise file names, there is a possibility that a file
already exists with the same name as one of the partitions to be created. Typically, the
solution is to move the partition that already exists. Use the MODIFY utility to specify a
name for the partition to be moved. This file can exist on the same volume as the
original, or on a different volume.
For details and examples, see the information about MODIFY in the SQL/MX
Reference Manual.
Creating SQL/MX Metadata
NonStop SQL/MX creates system metadata and user metadata tables that maintain
records of the information that defines SQL/MX objects and track the use of those
objects by other SQL/MX objects.
Note. NonStop SQL/MX does not prevent you from specifying a subvolume name that is
already in use by another schema. If you do, a Guardian wild card of the form
\system.$*.subvolume.* will include physical files from all schemas using the subvolume
name.