🧩 ORA-19573: Cannot Obtain Exclusive Enqueue for Datafile

🧩 Introduction

When performing an RMAN backup, restore, or recovery operation, you might encounter the error:

ORA-19573: Cannot obtain exclusive enqueue for datafile

This issue occurs when Oracle cannot gain exclusive access to a datafile because it is being used by another process or operation. It’s common in environments with concurrent sessions or when the database is partially open during recovery.

Root Cause

This error means another session or process is holding a lock (enqueue) on the datafile. Common causes include:

The datafile is online and in use during a restore or recovery.

The database is mounted or open when the command requires exclusive access.

Another RMAN job or process (e.g., DBWR or ARCH) is accessing the file.

The datafile is read-only, but RMAN tries to write to it.

The controlfile is out of sync with the datafile state.

How to Diagnose

You can check which datafile and process are causing the issue using:

SELECT file#, name, status FROM v$datafile;

Check enqueue locks:

SELECT * FROM v$locked_object;

Or to find out which session is holding the lock:

SELECT l.session_id, s.username, s.program

FROM v$locked_object l, v$session s

WHERE l.session_id = s.sid;

If you’re using RMAN, the log will show which datafile failed.

Possible Solutions

1️⃣ Ensure Database is in the Correct State

For restore or recovery, the database should be mounted but not open:

SHUTDOWN IMMEDIATE;

STARTUP MOUNT;

Then retry your RMAN command.

2️⃣ Offline the Datafile Before Recovery If the database must remain open, offline the affected datafile first:

ALTER DATABASE DATAFILE '<path_to_datafile>' OFFLINE;

Then perform the restore or recovery, and finally:

ALTER DATABASE DATAFILE '<path_to_datafile>' ONLINE;

3️⃣ Terminate Conflicting Sessions Find and kill any sessions holding locks:

SELECT s.sid, s.serial#

FROM v$session s, v$locked_object l

WHERE s.sid = l.session_id;

Then:

ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE;

4️⃣ Check for Active RMAN Jobs Sometimes, a previously failed RMAN job keeps a lock.

List active jobs:

SELECT SID, SERIAL#, CONTEXT, SOFAR, TOTALWORK, OPNAME

FROM V$SESSION_LONGOPS

WHERE OPNAME LIKE 'RMAN%';

Kill or wait for completion before retrying.

5️⃣ Synchronize Controlfile If the issue persists, crosscheck your datafiles:

RMAN> CROSSCHECK DATAFILE ALL;

RMAN> REPORT SCHEMA;

Ensure all files listed in the controlfile exist and are consistent.

Example Scenario

You attempt a restore with:

RMAN> RESTORE DATAFILE 5;

But get:

RMAN-03002: failure of restore command

ORA-19573: Cannot obtain exclusive enqueue for datafile 5

✅ Solution:

Mount the database (not open).

Ensure no other session is using datafile 5.

Retry the restore.

Best Practices

Always perform restore/recovery in MOUNT mode.

Avoid multiple RMAN sessions running simultaneously on the same DB.

Use catalog synchronization regularly (CROSSCHECK and DELETE EXPIRED).

Monitor and control session locks during maintenance operations.

Conclusion

The ORA-19573 error is primarily related to file locks preventing RMAN operations. By ensuring proper database state and eliminating conflicting sessions, you can quickly resolve the issue and maintain a smooth backup/recovery workflow.