Solved – How to fix ORA-00054 resource busy and acquire with NOWAIT specified or timeout expired?

Question: What is the cause of the Oracle error “ORA-00054 resource busy and acquire with NOWAIT specified or timeout expired”?

The error is raised when the following statement is executed against the Oracle Database.

    SQL> ALTER TABLE vst.account ADD (update_date varchar2(100));
    ERROR at line 1:
    ORA-00054: resource busy and acquire with NOWAIT specified

Answer: The Oracle error utility oerr shows this description for the ORA error.

    00054, 00000, “resource busy and acquire with NOWAIT specified or timeout expired”
    Interested resource is busy.

    Retry if necessary or increase timeout.

Cause: The statement requires an exclusive lock on the table.

If the table is active and has DML or DDL transactions against it the transaction will not be able to acquire the lock quickly. This will cause the transaction to fail and return the resource busy error to the session.


There are three workarounds to address this.


You can increased the timeout by modifying the DDL_LOCK_TIMEOUT parameter in your session. Once this is set Oracle will wait for the new TIMEOUT before returning the “ORA-00054: resource busy and acquire with NOWAIT specified” error.

    SQL> ALTER SESSION SET ddl_lock_timeout=900;
    Session altered.

    SQL> ALTER TABLE vst.account ADD (update_date varchar2(100));
    Table altered.

Using a LOOP

    CREATE PROCEDURE ddl_loop(run_sql varchar2)
    timeout_except EXCEPTION;
    PRAGMA exception_init(in_use, -54);
    WHILE true LOOP
    WHEN in_use THEN null;

Kill Session Or Shutdown Application

Who is holding the lock? To determine what Session and SQL is operating against the object, run a query against the v$access and the v$session tables to obtain this information.

    SELECT a.object, a.type, a.sid,
    s.serial#, s.username,
    s.program, s.logon_time
    FROM v$access a, v$session s
    WHERE a.sid = s.sid
    AND a.owner = ‘&owner’
    AND a.object = ‘&object_name’;

After determining the user who is accessing the table, determine if the DML being performed can be stopped temporarily or the session killed.

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Note: This Oracle documentation was created for reference for use by Vitalsofttech DBA’s. If you have any questions please post by clicking on the ASK A QUESTION link above.

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