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)