When it comes to running Oracle Database at scale, performance and reliability are everything — and Oracle offers several ways to achieve both.
But if you’ve ever felt confused by the names — Oracle Exadata, Oracle Exadata Cloud@Customer (ExaCC), and Oracle Exadata Cloud Service (ExaCS) — you’re not alone.
All three deliver the same powerful Exadata technology, yet they differ radically in where they run, who manages them, and how you pay for them.
In this article, we’ll break down the key differences between these three deployment models — from the fully on-premises Exadata systems to the hybrid ExaCC model and the fully managed ExaCS cloud service — so you can choose the best fit for your organization’s needs.
🔹Oracle Exadata
What it is:
A hardware + software engineered system built by Oracle, optimized specifically to run at very high performance.
Where it runs:
- On-premises in your data center (you buy and manage the hardware).
- Also forms the infrastructure that powers Oracle’s own cloud database services.
You manage:
- Hardware lifecycle (racking, power, cooling, patching, firmware)
- OS, Grid Infrastructure, and Database software
- Backup/recovery, upgrades, security, etc.
Use case:
- Large enterprises that want full control and ultra-high performance locally.
🔹Oracle Exadata Cloud@Customer (ExaCC)
What it is:
Same Exadata hardware but installed in your data center, while Oracle manages it like a cloud service.
Where it runs:
- Physically in your data center, but logically part of Oracle Cloud Infrastructure.
Oracle manages:
- Hardware maintenance, storage servers, compute servers, networking
- Grid Infrastructure, patching, updates, monitoring
You manage:
- Your databases only (create, drop, tune, backup, etc.)
- Everything else is managed by Oracle, just like in the cloud.
Use case:
- Enterprises needing cloud benefits (elasticity, subscription model) but with data residency or latency requirements that prevent moving data off-premises.
☁️ Oracle Exadata Cloud Service (ExaCS)
What it is:
The same Exadata hardware, but fully hosted and managed inside (OCI).
Where it runs:
- In Oracle’s public cloud data centers (you never see or touch the hardware).
Oracle manages:
- Everything below the database — hardware, OS, storage, networking, grid infrastructure, patching, updates, scaling, backups (if you want them managed)
You manage:
- Your databases only (create, drop, tune, configure, backups if self-managed)
Use case:
- Organizations that are ready to move to public cloud, want zero infrastructure management, and pay-as-you-go scaling.
📝 Full Comparison Table
| Aspect | (On-Prem) | (ExaCC) | (ExaCS) |
|---|---|---|---|
| Location | Your data center | Your data center | Oracle Cloud data center |
| Hardware ownership | You | Oracle | Oracle |
| Infrastructure management | You | Oracle | Oracle |
| Database management | You | You | You |
| Billing model | CapEx (buy) | OpEx (subscription) | OpEx (subscription) |
| Elastic scaling | Manual upgrades | Through OCI console | Through OCI console |
| Patching & updates | Done by your team | Done by Oracle | Done by Oracle |
| Connectivity | Local | Local + OCI integration | Cloud only (OCI) |
| Data residency requirement | Fully under your control | Fully under your control | In Oracle cloud region |
| Ideal for | Control & compliance on-prem | Cloud model but data must stay on-prem | Full cloud migration |
📌 Summary
- Exadata → You buy & run everything yourself.
- ExaCC → Oracle puts Exadata in your data center, but manages all infrastructure; you just manage DBs.
- ExaCS → Same Exadata but fully hosted in Oracle Cloud, you only manage DBs.