When performing a database upgrade, one of the most common issues DBAs face is the ORA-01092: ORACLE instance terminated and ORA-39701: database must be mounted EXCLUSIVE for UPGRADE or DOWNGRADE error combination.
This typically occurs when you attempt to open the database in UPGRADE mode in a Real Application Clusters (RAC) environment where the cluster_database parameter is set to TRUE.
Let’s look at the root cause and step-by-step solution.
The Error
When running the upgrade command, you might see:
SQL> ALTER DATABASE OPEN UPGRADE;
ALTER DATABASE OPEN RESETLOGS UPGRADE
*
ERROR at line 1:
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-39701: database must be mounted EXCLUSIVE for UPGRADE or DOWNGRADE
Process ID: 27228
Session ID: 144 Serial number: 15
This means the database is not in exclusive mode, and therefore Oracle refuses to continue the upgrade process.
Understanding the Cause
The ORA-39701 error message clearly indicates that the database must be mounted in EXCLUSIVE mode to perform an upgrade or downgrade.
In an Oracle RAC setup, the parameter cluster_database=TRUE means the instance is configured to operate as part of a cluster.
For upgrade or downgrade operations, Oracle requires only one instance to access the database.
Hence, the database must be mounted exclusively by a single instance, not shared across multiple nodes.
🔧 Step-by-Step Solution
Let’s walk through the complete fix for this issue.
Step 1: Mount the Database
First, start the database in mount mode:
SQL> STARTUP MOUNT;
Output:
ORACLE instance started.
Total System Global Area 1.7843E+10 bytes
Fixed Size 2191200 bytes
Variable Size 1.2415E+10 bytes
Database Buffers 5368709120 bytes
Redo Buffers 57352192 bytes
Database mounted.
Step 2: Check the Cluster Setting
Check whether cluster_database is set to TRUE:
SQL> SHOW PARAMETER cluster_database;
Output:
NAME TYPE VALUE
-------------------------------------- ----------- -----------------------------
cluster_database boolean TRUE
Step 3: Disable Cluster Mode Temporarily
Set cluster_database to FALSE:
SQL> ALTER SYSTEM SET cluster_database=FALSE SCOPE=SPFILE;
System altered.
You’ll see:
Step 4: Restart the Database
Shut down and restart the database for the parameter change to take effect:
SQL> SHUTDOWN IMMEDIATE;
Database closed.
Database dismounted.
ORACLE instance shut down.
Then start again in mount mode:
SQL> STARTUP MOUNT;
Database mounted.Output confirms it’s mounted exclusively:
Check again:
SQL> SHOW PARAMETER cluster_database;
Output:
NAME TYPE VALUE
-------------------------------------- ----------- -----------------------------
cluster_database boolean FALSE
Step 5: Open Database in Upgrade Mode
Now you can safely open the database in upgrade mode:
SQL> ALTER DATABASE OPEN UPGRADE;
Database altered.
Success — the database is now open in UPGRADE mode and ready for the patching or upgrade process.
Step 6 (Optional): Re-enable Cluster Mode After Upgrade
Once the upgrade is complete, remember to re-enable cluster mode:
SQL> ALTER SYSTEM SET cluster_database=TRUE SCOPE=SPFILE;
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP;
This restores normal RAC functionality for all nodes.
Real-World Tip
This issue is very common during RAC to standalone upgrade tests or major patch application (like 19c to 23ai).
Always check the cluster_database parameter before running any upgrade scripts.
Upgrades and downgrades require exclusive access — meaning only one instance should have the database mounted.
Quick Summary
| Step | Action | Description |
|---|---|---|
| 1 | STARTUP MOUNT | Mount the database without opening it. |
| 2 | SHOW PARAMETER cluster_database | Check cluster mode status. |
| 3 | ALTER SYSTEM SET cluster_database=FALSE SCOPE=SPFILE | Disable cluster mode. |
| 4 | SHUTDOWN IMMEDIATE → STARTUP MOUNT | Restart in exclusive mode. |
| 5 | ALTER DATABASE OPEN UPGRADE | Successfully open in upgrade mode. |
Related Oracle Upgrade Articles
- ORA-01555: Snapshot Too Old – Deep Dive into Undo and Query Consistency
- ORA-01114 / ORA-01110: Cannot Add Datafile or Write to File – Causes, Fixes & Prevention (Real Oracle DBA Guide)
- Oracle 19c Database Upgrade from 11.2.0.4 to 19c Using Manual Method
Final Thoughts
The ORA-01092 and ORA-39701 errors are simple to resolve once you understand Oracle’s exclusive mode requirement for upgrades.
By temporarily disabling the cluster configuration and restarting the instance, you ensure that your upgrade process runs smoothly — without forced disconnections or instance terminations.
Always verify cluster_database and undo_tablespace parameters before running upgrade scripts to avoid unexpected downtime.
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