Oracle Autonomous Database Internals: What the Self-Driving Engine Actually Does

Oracle Autonomous Database (ADB) is often described in marketing terms: “self-driving, self-securing, self-repairing.” For architects and senior DBAs, the more useful question is: what does it actually do automatically, how does it do it, and where do you need to intervene? This article peels back the automation layers. The Infrastructure Foundation Every ADB instance runs on Exadata Cloud Service (ExaCS). This is not incidental — it is the technical prerequisite for the automation that ADB delivers. The Smart Scan offload, HCC compression, and storage index features described elsewhere in this blog are all active beneath every ADB workload. ...

March 1, 2026 · 5 min · mardaff

ZDM Migration: Exadata X8 On-Premises to Oracle Database@Azure (ADB-S) via GoldenGate

This article presents a complete, real-world migration playbook for moving an Oracle Database from an on-premises Exadata X8 to Oracle Database@Azure Autonomous Database Serverless (ADB-S). The two data centres are 70 km apart, connected via a dedicated Azure ExpressRoute circuit. We use Oracle Zero Downtime Migration (ZDM) with GoldenGate replication to achieve a sub-minute application downtime. Environment Diagram ┌─────────────────────────────────────────────────────────────────┐ │ ON-PREMISES DATA CENTRE (Frankfurt) │ │ │ │ ┌──────────────────────────────────────────────────────────┐ │ │ │ EXADATA X8 FULL RACK │ │ │ │ │ │ │ │ ┌──────────────┐ ┌──────────────┐ │ │ │ │ │ x8db01 │ │ x8db02 │ Compute nodes │ │ │ │ │ (RAC inst1) │ │ (RAC inst2) │ │ │ │ │ └──────┬───────┘ └──────┬───────┘ │ │ │ │ └──────── IB ─────────┘ │ │ │ │ ┌──────────────────┐ │ │ │ │ │ Storage Cells │ (8 cells) │ │ │ │ │ x8cel01–x8cel08 │ │ │ │ │ └──────────────────┘ │ │ │ │ │ │ │ │ Database: ORCL (CDB), PDB: PDB_ERPSYS │ │ │ │ Size: 3.2 TB (data) + 400 GB indexes │ │ │ └──────────────────────────────────────────────────────────┘ │ │ │ │ ┌──────────────────────────────────────────────────────────┐ │ │ │ ZDM Service Host: zdmhost01.prod.example.com │ │ │ │ GoldenGate Extract: running on x8db01 (Integrated) │ │ │ └──────────────────────────────────────────────────────────┘ │ │ │ │ │ Azure ExpressRoute │ │ │ Dedicated, 10 Gbps, 70 km │ │ │ RTT: ~0.7 ms (measured) │ │ │ │ └─────────────────────┼──────────────────────────────────────────-─┘ │ ┌──────────────────────┼──────────────────────────────────────────┐ │ ORACLE DB@AZURE (West Europe — Amsterdam) │ │ │ │ │ ┌────────────────────▼──────────────────────────────────────┐ │ │ │ Oracle Database@Azure — ADB-S │ │ │ │ Display Name: adb-erpsys-prod │ │ │ │ DB Name: ADBERPSY │ │ │ │ Shape: 16 OCPUs, auto-scale │ │ │ │ Storage: 10 TB (elastic) │ │ │ │ TLS: mTLS (wallet-based) │ │ │ │ │ │ │ │ OCI GoldenGate (Managed Microservices deployment) │ │ │ │ GG Service: gg-erpsys-deployment │ │ │ │ Replicat: REP_ERPSYS (Integrated) │ │ │ └────────────────────────────────────────────────────────────┘ │ └──────────────────────────────────────────────────────────────────┘ Network Architecture On-Premises Exadata Azure ExpressRoute Oracle DB@Azure (Frankfurt DC) (Dedicated, 10 Gbps) (Amsterdam) 10.10.0.0/16 ───────────────────────────────────────► 172.16.0.0/16 Key Network Points: x8db01 public IP: 10.10.1.101 x8db01 SCAN IP: 10.10.1.200 (for GoldenGate source connection) zdmhost01: 10.10.5.50 OCI GoldenGate GW: 172.16.10.10 (private endpoint) ADB-S private EP: 172.16.20.5 (private endpoint in Oracle DB@Azure VNet) ExpressRoute Circuit: Provider: equinix-frankfurt Bandwidth: 10 Gbps dedicated Measured RTT (Frankfurt → Amsterdam): 0.7 ms Throughput achieved (iperf3): 9.2 Gbps (92% of capacity) Reference Environment SOURCE (On-Premises Exadata X8): RAC node 1: x8db01.prod.example.com (oracle user) RAC node 2: x8db02.prod.example.com Storage cells: x8cel01–x8cel08.prod.example.com ZDM host: zdmhost01.prod.example.com (oracle user, ZDM installed here) DB unique name: ORCL PDB: PDB_ERPSYS Data size: 3.2 TB DB version: 19.18.0.0 TARGET (Oracle DB@Azure): Region: Azure West Europe (Amsterdam) Resource Group: rg-oracle-prod ADB name: adb-erpsys-prod ADB DB Name: ADBERPSY Service name: adberpsy_high (high priority service) mTLS wallet dir: /etc/oracle/adb_wallet/ (on zdmhost01) OCI GG deploy: gg-erpsys-deployment (Microservices, managed by Oracle) OCI GG version: 21c ADMIN JUMP HOST: admin01.prod.example.com (used for OCI CLI, ZDM monitoring) Phase 1: Pre-Migration Assessment 1.1 Network Latency and Throughput Validation Before any migration work, validate the ExpressRoute circuit performance from the ZDM host: ...

March 1, 2026 · 10 min · mardaff