SQL/MP Installation and Management Guide

Planning Database Security and Recovery
HP NonStop SQL/MP Installation and Management Guide—523353-004
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Backing Up Indexes
Backing Up Indexes
The INDEXES option controls whether indexes are backed up automatically when the
underlying table is backed up. If you specify INDEXES IMPLICIT or use this option by
default, index definitions are backed up automatically with the underlying table,
regardless of whether it is explicitly named in the file set list. If you use the INDEXES
EXPLICIT option, only those indexes named in the file set list are backed up, and they
are copied in their entirety.
In either case, with either IMPLICIT or EXPLICIT, you must also back up any collations
used by the indexes.
The INDEXES IMPLICIT option produces this error message from the BACKUP utility,
whether you specify IMPLICIT or use it by default:
index-name *ERROR* SQL index-tables handled implicitly
This error generates a count of the files not backed up at the end of the BACKUP
operation; the count includes the indexes, because the index files are not actually
copied. When the underlying table is restored, however, indexes are re-created from
the catalog description, but the restored indexes are re-created without slack space,
regardless of whether or not they contained slack space. The error occurs in the
normal operation of BACKUP when INDEXES IMPLICIT is in effect.
The INDEXES EXPLICIT option could be applicable in these situations:
•
You want to retain the slack space in an index when it is restored.
•
The underlying table of a local index resides on a remote node.
Backing Up Views
Protection views are automatically backed up when you include the underlying table
name in the file set list of the BACKUP command. Protection views cannot be backed
up explicitly. In contrast, shorthand views are not automatically backed up unless you
specify the view names in the file set list of the BACKUP command.
No other options of the BACKUP and RESTORE commands enable you to control the
archiving of views.
When you back up a view, you must also back up any collations used by the view.
Caution. Use extreme caution when applying INDEXES EXPLICIT in a BACKUP operation.
Incorrect use of this strategy can result in making an index and its underlying table inconsistent
with each other.
For example, if you backed up a table with the INDEXES EXPLICIT option, deleted the
indexes, and then restored the table with the INDEXES EXPLICIT option, the table would be
corrupt because the table's file label no longer has any information about the indexes.