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Chapter 15Duplicating Databases and Transporting

Data

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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

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Filenames Might be Different from Source to Duplicate

Datafiles Control files Online redo log files Temp files

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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';

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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).

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During the Database Duplication

RMAN does the following:1. Generates a unique DBID for the new duplicate

database2. Creates a new control file for the duplicate database3. Restores the backups and performs an incomplete

recovery using all backups and archived redo logs4. Shuts down and starts up the auxiliary instance5. Opens the duplicate database with the resetlogs

option, thus clearing the online redo logs

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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

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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

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Steps for Replicating

1. Backup database

2. Verify the backup

3. Create directories and modify duplicate database initialization file

4. Startup auxiliary database in nomount mode

5. Check Oracle Net connections

6. Run duplicate database command

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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

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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”

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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

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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

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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;

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Resynchronizing a Duplicate Database

You can periodically synchronize a duplicate database with the primary

Rerun the duplicate database command Recopies the datafiles over

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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

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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

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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

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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