How do I fix error ORA 00054?
To avoid seeing Error ORA-00054? in the future, practice the following tips: Execute DDL during off-peak hours when the database is idle, such as late at night. Execute DDL during a maintenance window when all the end-users are locked out. Identify and kill the session that is preventing the exclusive lock.
How do you fix Ora 00054 resource busy and acquire Nowait specified or timeout expired?
Resolving the problem
- Find and stop the session that is preventing the exclusive lock.
- In Oracle 11g you can set ddl_lock_timeout, for example, allow DDL to wait for the object to become available, simply specify how long you would like it to wait: SQL> alter session set ddl_lock_timeout = 600; Session altered.
How do you resolve resource busy and acquire with Nowait specified?
The following steps fix the problem.
- LOCK TABLE ‘TABLE NAME’; — you will ‘wait’ (developers call this hanging). until the session with the open transaction, commits. This is a queue.
- Execute DDL. Your DDL will then run a lock with the NO WAIT.
- DDL auto-commits. This frees the locks.
How can I unlock a locked table in Oracle?
Unlock An Oracle Table
- Get the object ID of the locked table: SELECT object_id FROM dba_objects WHERE object_name=’YOUR TABLE NAME’;
- Get the SID values for this ID: SELECT sid FROM v$lock WHERE id1=OBJECT ID FROM STEP1.
- Get the session values for these SIDs:
- Kill the sessions causing the lock:
What is no wait in Oracle?
NOWAIT. This optional keyword tells Oracle not to wait if the table has been locked by another user. Control is immediately returned to your program, so it can do other work before trying again to acquire the lock.
How do I unlock a locked table in Oracle?
Why are tables locked in Oracle?
What are table locks in Oracle? Table locks perform concurrency control for simultaneous DDL operations so that a table is not dropped in the middle of a DML operation, for example. When Oracle issues a DDL or DML statement on a table, a table lock is then acquired.
How do I know if a table is locked in Oracle?
It might be easier to search for locks on a specific table using V$LOCKED_OBJECT which has an object_id column….
- select l.* from v$locked_object l, dba_objects o.
- where l.object_id = o.object_id.
- and o.object_type = ‘TABLE’
- and o.owner = upper(‘&owner’)
- and o. object_name = upper(‘&tabname’);
What is select for update?
The SELECT FOR UPDATE statement is used to order transactions by controlling concurrent access to one or more rows of a table. It works by locking the rows returned by a selection query, such that other transactions trying to access those rows are forced to wait for the transaction that locked the rows to finish.
What is for update no wait?
Question: What is the “for update nowait” and nowait options in updating rows?. Answer: Oracle provides the FOR UPDATE NOWAIT clause in SQL syntax to allow the developer to lock a set of Oracle rows for the duration of a transaction.
How do you release a table lock?
How do you check if any table is locked in Oracle?