11GR1 SNAPSHOT STANDBY

Sreekanth ChintalaGlobal Database Engineering

DELL IT PROD ENVIRONMENT

Oracle Versions

392

795

151Total: 1085

• Targets:  6126

• Cluster Databases: 289

• DB Instances: 1188

• Hosts: 1342, ASM Targets: 849

• 186 Physical Standbys2

CHARACTERISTICS

Fully updatable standbyProvides disaster recovery and data protectionRequires Flashback DatabaseCan not be part of switchover/failover until it returns to a physical standbyIn 11g the Data Guard Broker will convert it back to a Physical standby automatically upon manual failover.Flashback database limitations applyNo Real-Time QueryNo Fast-Start FailOver

DELL CONFIDENTIAL 3

HOW WE USE IT

Use as a Performance Testing environmentEliminate the guesswork, reliable and dependable resultsSave time and effort in data movementSave money through consolidationKnow the impact of changeOn production infrastructure and production dataRealistic view on resource consumptionNo surprises. Implement changes with confidence. Tuning isn’t a guess anymoreBest execution plan from real data or use SQL Performance Analyzer (SPA)

DELL CONFIDENTIAL 4

5

Standby

StandbyStandby

Time

Time

Apply Archive Logs

Read/Write Read/Write Read/Write

1

2

3 4 5

6

1. Prepare the Standby

2. Prepare the Primary

3. Create Guaranteed Restore Point

4. Convert Physical Standby to Read Write

5. Use Read Write Standby

6. Flashback to Restore Point

7. Convert standby back to Physical Standby

7

Standby

Apply Redo

Snapshot S

tandby in 10gR2

6

Standby

StandbyStandby

Time

Time

Read/Write Read/Write Read/Write

1 2

3

1. Convert to Snapshot Standby

2. Use Snapshot Standby

3. Convert to Physical Standby

Snapshot S

tandby in 11gR1

Apply Archive Logs

Standby

Apply Redo

7

Standby

StandbyStandby

Time

Time

Read/Write Read/Write Read/Write

1 2

3

1. Convert to Snapshot Standby

2. Use Snapshot Standby

3. Convert to Physical Standby

Use W

ith Real A

pplication Testing

Apply Archive Logs

Standby

…Replay Driver

Replay Driver

Apply Redo

8

DIFFERENCES

10gR2 11gR1

Manual Steps (OTN Paper)

Does not receive Redo from Primary during ‘Snapshot’ period

Can not use OEM/Grid Control

Single Command

Receives Redo from Primary all the time

Can use OEM/Grid Control(Requires Data Guard Broker)