Real Application Clusters

Oracle Real Application Clusters (RAC) allow customers to run a single Oracle Database across multiple servers in order to maximize availability and enable horizontal scalability, while accessing shared storage. User sessions connecting to Oracle RAC instances can failover and safely replay changes during outages, without any changes to end user applications, hiding the impact of the outages from end users.

Introducing Oracle Real Application Clusters 19c (3:18)

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New Generation Oracle RAC

Oracle Real Application Clusters 19c includes many improvements that enable applications to achieve significantly better levels of availability and scalability than previous versions. These improvements create a new generation of Oracle RAC technology ready to meet the needs of next-generation workloads and applications.

Oracle Real Application Clusters features

Key capabilities

Cache synchronization

Application developers connect to any database instance in the cluster without making any changes to the application reducing downtime.

Smart cluster reconfiguration

Customers reduce the impact of service disruptions by automatically redirecting connections to surviving instances.

Full stack protection

Oracle RAC provides end-to-end protection of customer databases by safely replaying transactions during outages without impacting end user experience.


Multi-platform support

Customers can standardize across their Oracle Database environments by using Oracle RAC in Oracle Cloud, on Oracle engineered systems, and on generic hardware.

Oracle does not support Oracle Real Application Clusters on Non-Oracle public cloud environments. For more information, refer to My Oracle Support Note 2688277.1.

Oracle Database Support for Non-Oracle Public Cloud Environments

Licensing choices

Customers reduce cloud and on-premises costs by using a combination of Oracle RAC subscription-based pricing and licenses.

Autonomous Database integration

Database administrators save time by utilizing pre-configured Oracle RAC capabilities in Autonomous Database.


Scale features and functions

Rapidly scale all Oracle Database features and functions across multiple instances to address sudden changes in customer workloads, without the need for manual intervention.

No application changes

Scale applications up to one hundred nodes in a cluster without application changes, improving DBA and developer productivity.

Faster OLTP

Oracle RAC improves Oracle Database performance for crucial enterprise application workloads, including Oracle E-Business Suite, Oracle PeopleSoft, and SAP ERP Central Component (ECC) by scaling workloads across all instances of the cluster.

More scalable analytics

Oracle RAC allows customers to easily scale analytics workloads by eliminating the need for replica databases and database level conflict resolution, significantly improving database administrator productivity.


Reduce unplanned downtime

Oracle RAC enables customer databases to continue to run across component failures, reducing potential data loss and minimizing unplanned downtime created by single-point-of-failure designs.

Eliminate planned downtime

Customers eliminate planned, maintenance related downtime by using Oracle RAC to implement rolling upgrades and patching on a server-by-server basis.


IT teams use Oracle RAC with Oracle Sharding to provide high availability for each shard in the database.


Tight integration with Oracle Active Data Guard and Oracle GoldenGate enables IT teams to maximize Oracle Database availability and protection using proven Oracle Maximum Availability Architecture (MAA) best practices.

Customer successes

Oracle Real Application Clusters are used by customers around the world to increase Oracle Database availability and scale database performance across multiple database servers.

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Wargaming uses Oracle RAC to achieve zero downtime for their databases

Oracle Real Application Clusters use cases

  • Provide continuous availability

    Maximize database availability by removing individual database servers as single points of failure for unplanned downtime and leverage rolling patching to eliminate planned downtime.

  • Scale Oracle Database workloads

    Dynamically scale databases without disrupting operations or requiring any changes to application code.

    Oracle Real Application Clusters 19c technical architecture (PDF)

  • Consolidate database environments

    Reduce infrastructure costs and the complexity of database environments by running more Oracle Database instances on fewer servers without compromising isolation requirements.

    Best practices for database consolidation (PDF)

  • Oracle Cloud Database Services

    Oracle Real Application Clusters is supported with Oracle Database Services in Oracle Cloud Infrastructure (OCI). Oracle does not support Oracle Real Application Clusters on Non-Oracle public cloud environments. For more information, refer to My Oracle Support Note 2688277.1.

    Oracle Database Support for Non-Oracle Public Cloud Environments

Explore more about Oracle RAC from customers and experts

Oracle RAC—The art of database options

Learn how Oracle RAC maximizes availability and enables horizontal scalability.

Simplify application development with Oracle RAC

Improve developer productivity with Oracle RAC.

Scaling PayPal workloads

Oracle RAC scales the most demanding online transaction processing workloads.

Related products and technologies

Oracle RAC One Node

Enhance availability for single instance databases

Application Continuity

Provide continuous availability

Oracle Clusterware

Use clustered servers as a single system

Automatic Storage Management

Simplified storage management

Advanced Cluster File System

POSIX and X/OPEN compliant cluster file system supports multiple OS

Autonomous Health Framework

Maintain database availability and performance

Autonomous Database

The future of Oracle Database

Oracle Engineered Systems

The Best Platform for Oracle Database

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