comparison and an optional diagram to help you better understand Oracle Data Guard and how it relates to other Oracle high availability (HA) and disaster recovery (DR) solutions:
🔄 Comparison: Data Guard vs. GoldenGate vs. Active Data Guard
Feature / Use Case Data Guard Active Data Guard Oracle GoldenGate
Main Purpose DR & HA (Disaster Recovery & High Availability) DR + Real-time reporting Real-time data replication & integration
Data Synchronization Redo log shipping Redo log shipping with read access Logical replication (SQL-based)
Standby Type Physical / Logical / Snapshot Physical standby only Logical replication across heterogeneous systems
Read-Only Reporting Not available (unless logical standby) ✅ Yes (on physical standby) ✅ Yes (on target system)
Automatic Failover ✅ Yes (with Data Guard Broker) ✅ Yes (with Data Guard Broker) ❌ No (manual intervention needed)
Replication Granularity Whole database Whole database Table / Schema / Database
Latency Very low (near real-time) Very low Low (depends on config)
Heterogeneous DB Support ❌ No (Oracle-only) ❌ No ✅ Yes (Oracle to/from other DBs)
Use Cases HA, DR, backup offloading HA + Reporting + DR Real-time data distribution, migration, ETL
📊 When to Use Which?
Use Data Guard if your goal is high availability and disaster recovery with Oracle-only environments.
Use Active Data Guard if you need disaster recovery plus live reporting from a synchronized copy.
Use Oracle GoldenGate if you need cross-platform replication, zero downtime migrations, or replication at table/schema level.
📉 Simple Diagram: Oracle Data Guard Architecture
[ Users / Applications ]
|
┌────────────┐
│ Primary DB │ ◄─── Active database
└────────────┘
|
┌──────────────┼────────────────┐
▼ ▼
[Redo Transport] [Redo Transport]
(Sync or Async) (Sync or Async)
| |
┌─────────────┐ ┌──────────────┐
│ Physical │ │ Logical │
│ Standby DB │ │ Standby DB │
└─────────────┘ └──────────────┘
| ▲ |
| └─ Real-time Apply └─ SQL Apply
|
└── Optional: Read-only queries (Active Data Guard)
📌 Summary
Data Guard = Reliable, Oracle-only disaster recovery.
Active Data Guard = Adds real-time reporting capability on standby.
GoldenGate = More flexible, supports heterogeneous databases and replication at finer levels.