Chapter 15 Duplicating Databases and Transporting Data

1. Chapter 15Duplicating Databases and Transporting Data

2. RMAN Duplication Features • You can duplicate a database without even making a backup of the source database first by using the new Oracle Database 11g technique of network-enabled duplication • You can register in the same recovery catalog as the primary database, since the duplicate database will have its own unique DBID • You can exclude certain tablespaces, such as the read-only tablespaces • You can duplicate the database on the same server or on a remote host • You can duplicate a database to a past point in time if you want

3. Filenames Might be Different from Source to Duplicate • Datafiles • Control files • Online redo log files • Temp files

4. Renaming Files in a Duplicate Database duplicate target database to dupdb from active database spfile parameter_value_convert '/a01', '/a20' set sga_max_size = 800m set sga_target = 700m set log_file_name_convert = '/a01','/a20', db_file_name_convert '/a01','/a20';

5. Creating a Duplicate Database on the Same Host These prerequisites apply to all database duplication jobs: • You must connect to both the target (source) database and the auxiliary (destination) instance. • You must start the auxiliary instance with the nomount option. • You can’t use a standby database as the target database. • You’ll need the password file for the auxiliary instance only if you’re using the RMAN client on a different host than the auxiliary host or if you duplicate from an active database (see recipe 15-3 and recipe 15-4) • The target database can be open or closed • Both the source and destination databases must be on the same operating system platform (32-bit and 64-bit versions of a platform are considered identical).

6. During the Database Duplication RMAN does the following: 1. Generates a unique DBID for the new duplicate database 2. Creates a new control file for the duplicate database 3. Restores the backups and performs an incomplete recovery using all backups and archived redo logs 4. Shuts down and starts up the auxiliary instance 5. Opens the duplicate database with the resetlogs option, thus clearing the online redo logs

7. Duplicating a Database Without Any RMAN Backups • In Oracle Database 11g you duplicate a database without having a backup • Use active database clause of duplicate database command • Network enabled database duplication

8. Duplicating a Database to a Remote Host w/same Filestructure • Nice feature for automating the replication of a database to another host • Might need to replicate a production database to another box for testing purposes • Troubleshooting production problems in a non-production environment

9. Steps for Replicating • Backup database • Verify the backup • Create directories and modify duplicate database initialization file • Startup auxiliary database in nomount mode • Check Oracle Net connections • Run duplicate database command

10. Duplicating a Database When Directories are Different • Quite often source and duplicate make have different directory structures • Use the db_file_name_convert parameter • Creates a new locations for datafiles and online redo log files

11. Creating a Standby Database on Different Host from Primary • Standby database (Data Guard) is Oracle’s disaster recovery tool • Physical standby database is a block for block copy of primary database • Use the syntax “backup current controlfile for standby format”

12. Duplicating a Database to a Point in Time in Past • May want to rebuild production database to a point in time in the past for testing purposes • May want to see a database as data existed for a point in time in the past • Use duplicate...until clause

13. Skipping Tablespaces • You may only need to duplicate part of a database • May not need tablespaces like tools or users in your duplicated tablespace • Use skip tablespace clause

14. Duplicating a Database with a Specific Backup Tag • You want to force RMAN to use a specific backup to be used when duplicating RMAN> list backup of database; • Change backupsets that you don’t want RMAN to use marked as unavailable RMAN> change backupset <primary key> unavailable;

15. Resynchronizing a Duplicate Database • You can periodically synchronize a duplicate database with the primary • Rerun the duplicate database command • Recopies the datafiles over

16. Transporting Tablespaces on the Same OS Platform • Use RMAN transport tablespace command • Tablespace must be self contained (no referential integrity to other objects in other tablespaces) • RMAN creates an auxiliary tablespace which it uses to create transportable tablespaces

17. Transporting Tablespaces Across Different Operating System Platforms • Big endian vis little endian format • If two operating systems use the same endian format, then no differences from previous example • If endian format different then you must convert the tablespaces being transported to match target operating system format

18. Transporting an Entire Database to a Different Platform • Useful for moving database from one operating system to another • Use convert database command • Transport doesn’t include bfiles, controlfiles, redo logs, and temp files

19. Transporting a Database by Converting Datafiles on the Target Platform • You may do this if you’re converting the source database to several different target platforms • Make sure source database is eligible for conversion • Use convert datafile command