DATA GUARD and FLASHBACK - Oracle High Availability · DATA GUARD and FLASHBACK –Stress Testing, HotFixes and Data Recovery April Sims Southern Utah University OCP 8i,9i,10g

DATA GUARD and

FLASHBACK – Stress

Testing, HotFixes and Data

Recovery

April Sims

Southern Utah University OCP 8i,9i,10g

Contributing Editor

If you want to become an

author or reviewer….

Standbys - 10gR2

Physical

• Block for Block Copy

• REDO APPLY

• Data Loss

Protection Modes

• Can be used for

reporting – not kept

current with

production

Logical

• Read-only

• SQL APPLY

• Add R/W schemas

• Some DDL skipped

• Datatype issues

• Reporting Instance

– current with

primary

DATA GUARD

• Role Management Services – Failovers and

Switchovers

• Reduces Errors

• Less Manual Intervention

• Faster Transitions

• More work to fail over different clients

• Heterogeneous Environment – More support

in 11g

Node BNode A

REDO APPLY

PRIMARY STANDBY

STANDBYPRIMARY

Node BNode A

REDO APPLY

DOWNSTANDBY

STBY> ALTER DATABASE

RECOVER MANAGED

STANDBY DATABASE FINISH

FORCE;

STBY> ALTER DATABASE

COMMIT TO SWITCHOVER

TO PRIMARY;

STANDBYPRIMARY

Node BNode A

REDO APPLY

DOWN STANDBY

STANDBYPRIMARY

Node BNode A

REDO APPLY

DOWN PRIMARY

PRMY> ALTER DATABASE

OPEN;

April Sims

DATA GUARD

DBA

Multiple Disaster Recovery Sites

Local Site

• Different Building, Same

City Block

• Different Subnet

• RTO* – 30 minutes

• Linux RH 4 (64-bit) AMD

• No data loss

• Logical Standby –

Reporting only

Remote Site

• 80 miles away

• Different IP, Exterior DNS

• VPN Tunnel

• RTO* – 24 hours

• SAME HARDWARE as

production

• No data loss

• Logical Standby data

already duplicated

*RTO – Recovery Time Objective

FLASHBACK

PRIMARY DATABASE

• Revert Logical Corruption

• Unroll patch or hot fix

• Similar to a full database

restore

• Affects ALL USERS!

STANDBY DATABASE **

• Physical Corruption

• Logical Corruption

• Vendor Upgrade

• Batch Job Reversal

• Untested Hot Fix, Patch

• Stress Testing

• Restore datafile *see Notes

• Oracle Upgrades

• Reinstate Primary

• ASM or RAC Migration

• Affects minimal number of

USERS!

**Different init.ora parameters

GUARANTEED RESTORE POINTS

• Requires FLASHBACK to be enabled

• Highly recommended

• Easy to convert back to correct SCN

• Resume role as physical standby

FLASHBACK STANDBY

PRMY> ALTER SYSTEM ARCHIVE LOG CURRENT;

PRMY> ALTER SYSTEM SET DG_BROKER_START=FALSE;

PRMY> ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=DEFER;

REDO APPLY is no longer running, Broker is automatically re-

enabled if not turned off. Logs aren’t shipping. All of these

things change in 11g!

STBY> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

STBY> CREATE RESTORE POINT HOTFIX1 GUARANTEE FLASHBACK DATABASE;

STBY> ALTER DATABASE ACTIVATE STANDBY DATABASE;

TEST……..…..remember Recovery Time Objective

After Testing….Revert

STBY> STARTUP MOUNT FORCE;

STBY> FLASHBACK DATABASE TO RESTORE

POINT HOTFIX1;

STBY> ALTER DATABASE CONVERT TO PHYSICAL

STANDBY;

STBY> STARTUP MOUNT FORCE;

STBY> ALTER DATABASE RECOVER MANAGED

STANDBY DATABASE USING CURRENT

LOGFILE DISCONNECT;

(*using REAL-TIME APPLY)

11g Features and Benefits

• Snapshot Database

• Active DATA GUARD

• RMAN

• Real Application Testing

• Flashback Transaction

• Fast Start Failover

• Redo – Compression and SSL Authentication

• Lost-Write Detection

• Live Database Duplication Over Network

11g

Snapshot

Database

• Data Frozen

• Receives Redo but not

applied

• Can be read-only

(reporting)

• Can be read-write (testing)

• Requires Flash Recovery

Area

• Less steps than in 10g

• Archival Purpose?? *

Third type of

standby….

* Not to be confused with RMAN Archival Backups

11g - ACTIVE DATA GUARD

• PHYSICAL Standby

• Open for reporting

• Current with Primary

• Unable to add additional R/W schemas,

summations, indexes, MV as with Logical

Standby

• Dual functionality - disaster recovery &

reporting solution.

• Less Errors, Issues as with Logical

• $$$$

11g - RMAN Changes

• DBID – Identical for Primary and Physical

Standby, Identical is option for Logical

• BLOCK CHANGE TRACKING – Faster

incremental backups

• DB_UNIQUE_NAME – backups available for

restore to all standbys and primary but they

may not be accessible – disk or image

backups

• ARCHIVE DELETION POLICY – critical for

DG implementations

Must restore application

data to SCN by….

• Point-in-time recovery

• Flashback Database

• Import/Export

TAKE A SNAPSHOT

11g- Real

Application

Testing

More 11g Stuff….

• FLASHBACK TRANSACTION – useful for

primary instance

• FAST START FAILOVER – conditions

• REDO TRANSPORT – protects archive logs

(can be data mined) with SSL authentication

• LOST WRITE DETECTION – writes that don’t

make it to disk

11g DATABASE DUPLICATION

OVER NETWORK

• Live Backup – can use either the primary or

the standby database or backups of either

DUPLICATE TARGET DATABASE FOR

STANDBY FROM ACTIVE DATABASE

DORECOVER;

• If duplicated on same box use

SET NEWNAME FOR DATAFILE,TEMPFILE…

( * docs/references - couple of wrong examples)

http://download.oracle.com/docs/cd/B28359_01/server.111/b28294

/rcmbackp.htm#sthref1563 equal signs and “ instead of ‘

http://www.dbaexpert.com/blog/?p=27

Oracle Database Experts

Maintained by Charles Kim

Data Guard 11g Database Duplication Over Network Logfile

Posted in August 13th, 2007

by ckim in Data Guard

orapwd file=$ORACLE_HOME/dbs/orapwDBA11g entries=25 password=oracle123

DBA11gDR > ./dup.ksh

Recovery Manager: Release 11.1.0.6.0 - Production on Mon Aug 13 21:46:38 2007

Copyright (c) 1982, 2007, Oracle. All rights reserved.

RMAN>

connected to target database: DBA11G (DBID=231973368)