SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Performing Recovery Operations
HP NonStop SQL/MX Installation and Management Guide—523723-004
12-31
Using FIXUP to Correct Problem Data and Objects
you can use the MXCI SHOWLABEL command to get more details for a specific
Guardian file. See the SQL/MX Reference Manual for command syntax and example
outputs.
Guardian files have a set of DP2 labels attached to them that contain basic
information, such as file type, extent sizes, security, and timestamps. A separate entity,
a resource fork, is attached to an SQL/MX file. A resource fork contains additional
information about an SQL/MX file, including its associated ANSI name, ANSI
namespace, versioning information, record structure, key structure, partition maps, and
so on.
INFO displays:
•
The ANSI file name
•
The ANSI namespace, including the table namespace (which includes views and
stored procedures), index namespace, and trigger namespace
•
Versioning elements, including the object schema version
Using FIXUP to Correct Problem Data and Objects
NonStop SQL/MX stores information about object structures in metadata, resource
forks, and DP2 file labels. DP2 file labels consist of file structure information and
security settings. Resource forks contain specific SQL/MX information that includes,
among other things, the ANSI name, partition maps, row and key information, and
system metadata location. Metadata contains descriptions of all objects in a database.
While performing database operations, information between metadata, DP2 labels, and
resource forks can become inconsistent. For example, a failed TMF transaction might
leave a file in the broken state, or a software bug might not set the redefinition
timestamp correctly. When such an inconsistency is detected, it must be fixed to
guarantee proper execution of NonStop SQL/MX.
Options for repairing broken objects include:
•
A label repair operation, which enables you to change a select group of file
attributes for a partition or an object. Use this option to get a system back and
running without performing an expensive restore or TMF recover operation.
•
A metadata repair operation, which allows the super ID user to make explicit
metadata changes through UPDATE, DELETE, and INSERT statements on
metadata tables issued from a licensed MXCI process.