Updated March 13, 2023
Introduction to DB2 restore
DB2 provides different kinds of commands to the user. DB2 restore is one of the commands that is provided by DB2. In DB2 restore, we can restore the database by using the DB2 backup utility. Basically, the restore command is used to encrypt the existing database that means we can create the backup of the database. The utility performs different operations such as we can overwrite the database by using different images, or we can say restore that database. We can restore the backup images in version 9.7 of DB2. Sometimes we need to upgrade; then, it will be automatically at the end restore command.
Syntax
db2 restore database specified database name from specified location taken at timestamp
Explanation
In the above syntax, we use the restore database command to restore the database; the restore command uses different parameters such as specified database name means actual database name that we need to store from the specified location of the database with the timestamp as shown in the above syntax.
How restore command works in DB2?
Now let’s see how the restore command works in DB2 as follows.
The backup utility provides the different services to restore the database as follows.
- If the database was empowered for roll-forward recovery at the hour of the backup activity, the database can be brought to its past state by beginning the roll forward utility after effective consumption of a restore activity.
- Restore a specified tablespace level backup activity.
- Transport a bunch of specified tablespaces, storage groups, and SQL schemas from database backup picture to a database by utilizing the TRANSPORT choice. However, the TRANSPORT alternative cannot vehicle a tablespace that has a table that has lists and imperatives characterized (if there are any) that share a similar name. Therefore, the TRANSPORT alternative isn’t upheld in the Db2 environment.
- On the off chance that the database name exists when this command is given, it replaces and reclassifies all storage groups as they were at the time the backup picture was created, except if in any case diverted by the client.
The pictures and pictures just catching contrasts from the hour of the past catch (called a delta picture) can’t be restored when there is a distinction in working frameworks or word size (32-digit or 64-cycle).
Following an effective restore activity from one environment to an alternate climate, no gradual or delta backup is permitted until a non-steady backup is taken. (This isn’t an impediment following a restore activity inside a similar framework).
Indeed, even with a fruitful backup activity from one environment to an alternate climate, a few contemplations exist: bundles should be a bounce-back before use (utilizing the BIND command, the REBIND command, or the db2rbind utility); SQL methodology should be dropped and re-made, and all outside libraries should be revamped on the new stage. (These are not contemplations when reestablishing a similar environment).
A restore activity that is run over a current database and existing holders reuses similar compartments and table space maps.
A restore activity that is run against another database reacquires all holders and reconstructs an improved table space map. A restore activity that is run over a current data set with at least one missing compartment additionally reacquires all holders and reconstructs a streamlined table space map.
Scope of the restore command
This command affects only local nodes.
Authorization
If we need to restore the database, then we need one of the following authorities as follows.
- System Admin permission.
- System control permission.
Required Connection
- We must require a database connection to restore the existing database.
- Instance and database connection must be required.
Now let’s see the different parameters used by the restore command as follows.
Database alias: Alias is a source database name from backup.
Continue: This is used for containers, and this final step in a restore operation.
Abort: Abort means it stops the execution of the restore command.
User name: It specifies the user name that makes the connection to the existing database.
Password: The password is used to verify the user name.
Rebuild tablespaces from the database:
This is used to restore the database from all specified tablespaces.
Rebuild tablespace from the image:
Restore the database with just the tablespaces in the picture being reestablished. This reestablishes overwrites a data set if it as of now exists.
Rebuild tablespace from the image except for rebuild-
Tablespace clause:
Restore the database with just the tablespaces in the picture being restored aside from those predetermined in the list. This restore overwrites a database on the off chance that it as of now exists.
Rebuild with tablespace-clause:
Restore the database with just the rundown of tablespaces indicated. This restore overwrites a database on the off chance that it as of now exists.
TABLESPACE tablespace-name:
A list of names that are utilized to indicate the tablespaces that are to be restored.
Table space names are required when the TRANSPORT choice is specified. This choice may take as much time as a full restore activity.
Schema name:
A list of names that are utilized to determine the patterns that are to be restored.
Online:
This implies that different specialists can associate with the database while the backup picture is being restored and that the database in other tablespaces is accessible while the predefined tablespaces are being restored.
Examples of DB2 restore
Now let’s see a different example of the DB2 restore command as follows.
First, create a directory using the mkdir command; after that, we terminate the database connection by using the following statement.
db2 terminate
Now take the backup of the UP database by using the following statement as follows.
backup database UP to /home/
Explanation
In the above statement, we use the backup utility to backup the database. The end out we illustrate by using the following screenshot as follows.
Now restore the database by using the following statement as follows.
restore backup UP from /home/ taken at 20210506084737
Explanation
In the above example, we use the restore command to restore the database that UP from the home directory, as shown in the above statement. The end out we illustrate by using the following screenshot as follows.
Conclusion
We hope from this article you learn the DB2 restore database command. From the above article, we have learned the basic syntax of the restore command and how it works, and we also see different examples of restore commands. From this article, we learned how and when we use the DB2 restore database command.
Recommended Articles
This is a guide to DB2 restore. Here we discuss the basic syntax of the restore command and how it works, and we also see different examples. You may also have a look at the following articles to learn more –
