Limitations to automatic incremental restore

The automatic incremental restore is useful when you need to restore your database. However, you should consider the limitations of automatic incremental restore when you are deciding how you will recover your database to prevent unnecessary issues.

The following limitations affect automatic incremental restore:

If a table space name has been changed since the backup operation you want to restore from, and you use the new name when you issue a table space level restore operation, the required chain of backup images from the database history will not be generated correctly and an error will occur (SQL2571N).
Example:
```
db2 backup db sample —> <ts1>
db2 backup db sample incremental —> <ts2> 
db2 rename tablespace from userspace1 to t1 
db2 restore db sample tablespace ('t1') incremental automatic taken 
at <ts2>

SQL2571N Automatic incremental restore is unable to proceed. 
Reason code: "3".
```
Suggested workaround: Use manual incremental restore.
If you drop a database, the database history will be deleted. If you restore the dropped database, the database history will be restored to its state at the time of the restored backup and all history entries after that time will be lost. If you then attempt to perform an automatic incremental restore that would need to use any of these lost history entries, the RESTORE utility will attempt to restore an incorrect chain of backups and will return an "out of sequence" error (SQL2572N).
Example:
```
db2 backup db sample —> <ts1>
db2 backup db sample incremental —> <ts2>
db2 backup db sample incremental delta —> <ts3>
db2 backup db sample incremental delta —> <ts4>
db2 drop db sample 
db2 restore db sample incremental automatic taken at <ts2>
db2 restore db sample incremental automatic taken at <ts4>
```
Suggested workarounds:
- Use manual incremental restore.
- Restore the history file first from image <ts4> before issuing an automatic incremental restore.

If you restore a backup image from one database into another database and then do an incremental (delta) backup, you can no longer use automatic incremental restore to restore this backup image.

Example:

db2 create db a
db2 create db b

db2 update db cfg for a using trackmod on

db2 backup db a —> ts1
db2 restore db a taken at ts1 into b

db2 backup db b incremental —> ts2

db2 restore db b incremental automatic taken at ts2

SQL2542N No match for a database image file was found based on the source
database alias "B" and timestamp "ts1" provided.

Suggested workaround:

Use manual incremental restore as follows:

db2 restore db b incremental taken at ts2
db2 restore db a incremental taken at ts1 into b
db2 restore db b incremental taken at ts2

After the manual restore operation into database B, issue a full database backup to start a new incremental chain