Hi,

Oracle generally recommends using a single custom schema for Oracle E-Business Suite (EBS) customizations, rather than multiple custom schemas. This recommendation is based on several factors and best practices that Oracle has outlined over the years. However, please note that Oracle's recommendations can evolve, so it's essential to consult Oracle's official documentation and support resources for the most current guidance. Here are some reasons behind the recommendation for a single custom schema:

1. Consistency and Maintainability: A single custom schema can provide a more consistent and easier-to-maintain environment for customizations. When all customizations are in one schema, it's simpler to manage, maintain, and troubleshoot them. This can lead to a more streamlined development and support process.
2. Easier Upgrades: Oracle EBS upgrades often require modifications to customizations to make them compatible with the new version. Having customizations in a single schema can make it easier to identify and update them during the upgrade process. This reduces the complexity of upgrading multiple custom schemas and ensures a smoother transition to newer EBS versions.
3. Data Integrity: Using a single schema can help maintain data integrity and referential integrity constraints across different parts of the application. It ensures that data relationships and dependencies are maintained correctly.
4. Performance: While multiple custom schemas can provide isolation, they can also lead to performance overhead due to cross-schema queries and data synchronization. A single schema can optimize performance by minimizing these overheads.
5. Security: Oracle provides security features that can be effectively implemented within a single schema. You can control access and permissions using Oracle's built-in security mechanisms, which are designed to work seamlessly within a single schema.
6. Easier Backup and Recovery: Managing backups and recovery operations is often simpler with a single schema because all customizations and application data are located in one place. This simplifies disaster recovery planning and execution.
7. Simplified Patching: When Oracle releases patches or updates for EBS, applying them is typically easier when customizations are in a single schema. Patching can be more straightforward as there's a single codebase to modify.
8. Compatibility and Support: Oracle's support and troubleshooting resources are designed with the assumption that customizations are in a single schema. This can make it easier to engage Oracle Support for assistance when needed.

It's important to note that while a single custom schema is often recommended, there can be specific scenarios where multiple custom schemas are justified. These scenarios might include stringent security requirements, data isolation needs, or cases where there are separate customizations for different business units with minimal overlap.

Ultimately, the decision on whether to use a single custom schema or multiple custom schemas should be made after a careful assessment of your organization's specific requirements, taking into consideration factors such as performance, maintenance, and security. Additionally, consulting with Oracle experts or your Oracle account representative can provide valuable insights into the best approach for your particular situation.

Thank you for detailed explanations