If the RDAREAs to be recovered include the master directory RDAREA, it is necessary to start HiRDB with the pdstart -r command and recover the master directory RDAREA with the pdrstr command.

In a recovery to the most recent synchronization point or with range specification, first recover the master directory RDAREA by itself, and then recover the other RDAREAs.

The two data dictionary LOB RDAREAs are classified as follows:

• For storage of the sources for stored routines and triggers
• For storage of the objects of stored routines and triggers

The recovery timing differs for the two data dictionary LOB RDAREAs.

(a) Recovering the data dictionary LOB RDAREA for storing sources

The data dictionary LOB RDAREA for storing sources can be recovered to the backup acquisition point or to any synchronization point since the backup acquisition point. The backup and system log (unload log) are used as the input to the database recovery utility.

(b) Recovering the data dictionary LOB RDAREA for storing objects

The data dictionary LOB RDAREA for storing objects can be recovered only to the backup acquisition point because a database update log required for rollforward is not collected. Only the backup is used as the input to the database recovery utility.

In the following cases, follow the given procedure to recover the data dictionary LOB RDAREA for storing objects:

• You are recovering the data dictionary LOB RDAREA for storing sources to a synchronization point after the backup acquisition point, but the data dictionary LOB RDAREA for storing sources cannot be synchronized with the data dictionary LOB RDAREA for storing objects
• The backup was collected by the pdcopy command with the -J option specified, but the data dictionary LOB RDAREA for storing objects was intentionally not backed up

Procedure

To recover the data dictionary LOB RDAREA for storing objects:

1. Use the pdmod command to reinitialize the data dictionary LOB RDAREA for storing objects:
   pdmod -a /pdmod/mod01
   
2. Use ALTER ROUTINE to re-create the SQL objects of all stored routines and triggers.
   ALTER ROUTINE ALL
   

When user LOB RDAREAs are recovered, the user RDAREAs for storing the corresponding LOB column structure base tables should also be recovered at the same time.

List RDAREAs do not become the targets of the pdrstr command. Because a list can be re-created if its base table is available, these RDAREAs are not subject to recovery.

If a list RDAREA is placed in error shutdown status, use the following procedure to release the shutdown status.

Procedure

To release the shutdown status for a list RDAREA:

1. Use the pdclose command to close the RDAREA that has been placed in error shutdown status.
2. Use the pdmod command to re-initialize the list RDAREA.
3. Use the pdrels -o command to release the list RDAREA from error shutdown status and open it.
   

   Note

   If a list RDAREA is re-initialized, all lists in that RDAREA become unusable. In such a case, you must re-create the lists with the ASSIGN LIST statement.

If you execute the pdstart -r command to start HiRDB and recover an RDAREA from error shutdown, you must perform shutdown release (pdrels command) on the RDAREA after HiRDB has started normally.

(a) Notes on RDAREAs to be backed up and recovered

When you back up a sequence generator RDAREA, back up the RDAREA that stores the table used by the sequence generator at the same time.

Also, when you recover the sequence generator RDAREA and the RDAREA that stores the table used by the sequence generator, be sure to recover them at a point at which their integrity can be assured. Otherwise, the sequence numbers obtained from the sequence generator following recovery might have duplicate or skipped numbers.

(b) Notes on recovery using logs

If you use logs to recover a sequence generator with a value greater than 1 specified for the log output interval, either to an arbitrary synchronization point at or following a backup acquisition point, or to the most recent synchronization point immediately before the error occurred, the sequence numbers obtained from the sequence generator following recovery might have skipped some numbers. This has nothing to do with whether sequence numbers are obtained from the applicable sequence generator between the backup acquisition and the synchronization point when recovery is finished.

The following table shows the situation in which sequence numbers having duplicate or skipped numbers following a recovery using logs occurs.

Table 21-2 Situation in which sequence numbers with duplicate or skipped numbers following a recovery using logs occurs

Item	Recovery to a backup acquisition point		Recovery to an arbitrary synchronization point at or following a backup acquisition point or to the most recent synchronization point immediately before the error occurred
	Value specified for the log output interval#		Value specified for the log output interval#
	1	Value greater than 1	1	Value greater than 1
Duplicate number	N	N	N	N
Skipped number	N	N	N	Y

Legend:

N: Does not occur

Y: Occurs

#

For details about the log output interval, see the HiRDB Version 9 UAP Development Guide.

Note that HiRDB Datareplicator and HiRDB Dataextractor cannot use a sequence generator. Therefore, when the extracting side and the target side are switched to use a sequence generator with the same name, the current value of the sequence generator cannot be inherited from the extracting side to the target side. Consequently, duplication might occur among the sequence numbers obtained from the sequence generator.

Since backup cannot be made, the temporary table RDAREA cannot be recovered. If an error occurs in the temporary table RDAREA, enter the pdmod command to re-initialize it.

When you re-create the HiRDB file system area of an RDAREA that must be recovered following a problem such as a disk error, make the settings listed below match those in the HiRDB file system area before the modification. If the settings are modified, it might not be possible to recover the database.

• File type (regular file or character special file)
• Specification of the -a option for the pdfmkfs command (whether to apply the RDAREA automatic extension method that automatically expands the HiRDB file system area)