Transcript Chapter 15 Duplicating Databases and Transporting Data

Chapter 15
Duplicating Databases and
Transporting Data
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RMAN Duplication Features
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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
Filenames Might be Different from
Source to Duplicate
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Datafiles
Control files
Online redo log files
Temp files
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
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
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Duplicating a Database Without Any
RMAN Backups
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In Oracle Database 11g you duplicate a
database without having a backup
Use active database clause of duplicate
database command
Network enabled database duplication
Duplicating a Database to a Remote
Host w/same Filestructure
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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
Steps for Replicating
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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
Duplicating a Database When
Directories are Different
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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
Creating a Standby Database on
Different Host from Primary
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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”
Duplicating a Database to a Point in
Time in Past
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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
Skipping Tablespaces
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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
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
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You can periodically synchronize a duplicate
database with the primary
Rerun the duplicate database command
Recopies the datafiles over
Transporting Tablespaces on the Same
OS Platform
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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
Transporting Tablespaces Across
Different Operating System Platforms
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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
Transporting an Entire Database to a
Different Platform
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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
Transporting a Database by Converting
Datafiles on the Target Platform
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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