Oracle Data Guard Protection Modes
Oracle Data Guard Protection Modes
Balance between data safety and performance — you choose the right level for your business
What Are Protection Modes?
Oracle Data Guard offers three protection modes, each defining how redo data is sent from the primary to the standby — and what trade-offs are made between data safety, availability, and performance.
Think of it like choosing between:
- Speed
- Safety
- Or a smart balance
Real-Life Analogy:
Imagine you’re sending important company files to a remote backup location:
- Maximum Performance = You drop them in a box and ship instantly. Fast, but no proof it reached.
- Maximum Availability = You ship it with a confirmation receipt — a little slower but safer.
- Maximum Protection = You don’t move forward until you’re 100% sure the backup received it. Total safety, zero risk.
1. Maximum Performance
Fastest, but allows some data loss
| Category | Details |
|---|---|
| Goal | Best primary DB performance |
| Redo Transfer | Asynchronous (ASYNC) |
| Sync Required? | No, primary doesn’t wait |
| Failover Risk | Possible data loss (some redo might not reach standby) |
| Best For | High-load systems, performance-critical apps |
| Analogy | Like sending a package without tracking — fast, but no delivery proof |
2. Maximum Availability
Balance of speed and safety
| Category | Details |
|---|---|
| Goal | Zero data loss with uptime as priority |
| Redo Transfer | Synchronous (SYNC) |
| Sync Required? | Yes, standby must acknowledge before commit |
| Failover Risk | No data loss if standby is reachable Switches to performance mode if not |
| Best For | Most production systems, banking, ERP |
| Analogy | Like a courier with signature — guaranteed delivery unless network fails |
3. Maximum Protection
Absolute safety, no data loss allowed
| Category | Details |
|---|---|
| Goal | Zero data loss — no compromise |
| Redo Transfer | Synchronous (SYNC) |
| Sync Required? | Yes, must receive acknowledgment from standby before commit |
| Failover Risk | None — not even a single redo lost |
| Impact | Primary database shuts down if standby is unreachable |
| Best For | Highly regulated industries, financial systems |
| Analogy | Like a locked vault — it won’t let anything out until a copy is secured |
Quick Comparison Table
| Mode | Redo Transfer | Data Loss Risk | Primary Waits? | If Standby Fails… | Best For |
|---|---|---|---|---|---|
| Max Performance | Async | ⚠️ Possible | ❌ No | Primary keeps running | Speed-focused apps |
| Max Availability | Sync | ✅ Zero* | ✅ Yes | Switches to Max Performance | Balanced critical workloads |
| Max Protection | Sync | ❌ None | ✅ Yes | ❌ Primary shuts down | Highly sensitive environments |