Hybrid Read-Only Mode in Oracle Database 26ai

Oracle continues to evolve its multitenant architecture with features that improve flexibility, availability, and control. One of the most impactful enhancements in Oracle Database 26ai is Hybrid Read-Only Mode—a smart balance between operational continuity and administrative control.

What is Hybrid Read-Only Mode?

Hybrid Read-Only Mode allows a Pluggable Database (PDB) to operate in a unique state where:

• Local users are restricted to read-only access
• Common users (like SYS, SYSTEM, or other CDB-level users) still have read-write privileges

This means that while application users can continue querying data, administrative users can still perform critical changes in the background.

How It Works

In a traditional setup:

• A READ ONLY PDB blocks all write operations (including admin tasks)
• A READ WRITE PDB allows full access to everyone

With Hybrid Read-Only Mode:

• Oracle introduces a middle ground
• Local users - No data modifications allowed
• Common users - Full administrative control remains intact

This separation ensures better governance and operational safety.

Comparison of Modes

Let's get our hands dirty and see how this feature works in a practical lab scenario. We'll use a PDB named ORCLPDB for this demonstration.

First, connect as a privileged user to the root container. You'll need to close the PDB before you can reopen it in the new hybrid state.

Close the PDB:- 

Open the PDB in the new hybrid mode

Verify the State

Test the Access Levels

As a Local User

Hybrid Read-Only Mode in Oracle 26ai is a strategic enhancement that empowers administrators to maintain and patch databases with minimal disruption. It strikes a balance between operational safety and flexibility, making it a valuable tool in modern database management.

Oracle Document :- https://blogs.oracle.com/ace/how-to-use-the-new-hybrid-readonly-mode-for-pluggable-databases-in-oracle-database-23c-free-developer-release

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