ORA-02049: timeout: distributed transaction waiting for lock tips Oracle Tips by Burleson Consulting November 17, 2011

Question:  I am getting an intermittent ORA-02049: timeout: distributed transaction waiting for lock error?  How do I keep the ORA-02049 from happening?

Answer:  Are you closing your database links with dbms_session.close_database_link? 

See MOSC note: 1018919.102 and look at adjusting your distributed_lock_timeout value and distributed_recovery_connection_hold_time.

ORA-02049: time-out: distributed transaction waiting for lock

Cause: The time to wait on a lock in a distributed transaction has been exceeded. This time is specified in the initialization parameter DISTRIBUTED_LOCK_TIMEOUT.

Action: This situation is treated as a deadlock and the statement was rolled back. To set the time-out interval to a longer interval, adjust the initialization parameter DISTRIBUTED_LOCK_TIMEOUT, then shut down and restart the instance.

Oracle connections remains open until you end your local session or until the number of database links for your session exceeds the value of OPEN_LINKS. To reduce the network overhead associated with keeping a database link open, then use this clause to close the link explicitly if you do not plan to use it again in your session.

Oracle MOSC describes an issue with ORA-02049 in which the error occurs along with ORA-01403 in DBMS_REPCAT.EXECUTE.  Here is an example of ORA-02049 occurring in this context:

ksedmp: internal or fatal error
ORA-02049: timeout: distributed transaction waiting for lock
ORA-06512: at "SYS.DBMS_DEFER_INTERNAL_SYS", line 193
ORA-02063: preceding 2 lines from DATA_HK_PROD
ORA-01403: no data found
ORA-06512: at "ACTSLAB.COMPANY_TAT$RP", line 168
ORA-01085: preceding errors in deferred rpc

This ORA-02049 happens as you attempt to run DBMS_REPCAT.EXECUT in a particular job or manually.
 

To resolve ORA-02049, you would need to increase the SHARED_POOL_SIZE value in init.ora .  If you find that the shared pool is large enough and the ORA-02049 error continues to exist, you may also want to try flushing the shared pool with ALTER SYSTEM FLUSH SHARED_POOL; to free even more space.

This should resolve ORA-02049 in this context because errors logged in DEFERROR actually use the SYS.DBMS_DEFER_INTERNAL_SYS package.  Because it is big, the SYS.DBMS_DEFER_INTERNAL_SYS package can't be loaded in a shared pool when there is an error such as ORA-02049.  This being, the package can load if the shared pool is flushed or the SHARED_POOL_SIZE is increased.

 

Ihis Oracle Forum thread offers further information regarding the ORA-02049 error.  Here, ORA-02049 is said to sometimes be caused by a transaction that waited for a locked object for so long that it times out. 

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