Databases: Autonomous Database, DB Systems, and Migration Options
What this domain tests
Database questions test whether you pick the right managed service for a requirement and understand the operational limits of each: who patches, how you connect, how backups work, and which migration tool meets a downtime target.
Core rules
- Autonomous Database runs on shared Exadata (serverless) or dedicated Exadata infrastructure. You choose a workload type - Transaction Processing or Data Warehouse - and scale compute and storage online. There is no OS access and no SYSDBA.
- Automatic backups are enabled by default with a default retention window you can extend, and Autonomous Data Guard provides a standby for failover.
- Connectivity uses TLS with a wallet (mTLS) or TLS, with optional private endpoints inside a VCN subnet and ACLs for allowed clients.
- Base Database Service (VM DB systems, bare metal, Exadata) provides OS-level control, RAC on bare metal, and Data Guard.
- Migration: Zero Downtime Migration for Oracle-to-Oracle moves, GoldenGate for continuous replication and minimal downtime, Data Pump for logical exports, RMAN for physical backups, and OCI Database Migration for heterogeneous sources.
Worked example
A 5 TB on-premises production database allows 15 minutes of downtime. Take an initial Data Pump or RMAN seed into the target, then run GoldenGate to replicate ongoing changes; at cutover, stop writes, let replication drain, and repoint the application. That design meets the target because only the final drain is downtime.
Traps
Expecting SSH or SYSDBA on Autonomous Database; configuring Data Guard between mismatched database versions or editions; forgetting the Object Storage bucket and IAM policy that DB backups need; assuming serverless Autonomous runs on Exadata infrastructure you control - that requires dedicated infrastructure.