Oracle DBA

Deadlock ORA-00060 error August 22, 2011

Filed under: Errors,Oracle — gaphydba @ 11:44 am
What is deadlock?
Deadlock is a situation in which two or more users are waiting for data locked by each other. deadlocks prevent some transactions from continuing to work.
How to resolve deadlock?
We have to do nothing to resolve deadlock error (ORA-00060), oracle automatically detects and resolve the deadlock by rolling back one statement involve in the statement. releasing one set of conflicting row locks.
Why deadlock error occurs?
deadlock is completely application bug. ask DEVELOPER to look into the coding on particular form (query) which raise DEADLOCK.
What is the reason for deadlock?
Deadlocks most often occur when transactions explicitly override the default locking of oracle database. because oracle database not escalate locks and does not use read locks for queries. but does use row-level locking, deadlocks occurs infrequently.

SOME Errors in Oracle and their solutions June 10, 2010

Filed under: Errors,IT,Oracle — gaphydba @ 4:20 pm

SQL> ORA 12545 Connect failed because target host or object does not exist

Cause: The address specified is not valid, or the program being connected to does not exist.
Action: Ensure the ADDRESS parameters have been entered correctly; the most likely incorrect parameter is the node name. Ensure that the executable for the server exists (perhaps “oracle” is missing.) If the protocol is TCP/IP, edit the TNSNAMES.ORA file to change the host name to a numeric IP address and try again.

SQL> ORA-12541: TNS no listener

Cause: Listener for the source repository has not been started.

Action: Start the Listener on the machine where the source repository resides.

manually u cant do by  $ORACLE_HOME/bin/lsnrctl start FOR UNIX IN CASE  ON WINDOWS goto control panel / services
u can see the listenerservice for the sid u have created.
start it!

ORA-01665: controlfile is not a standby controlfile

Then ‘copy’ standby control file to other host and be sure its being used.

1) use an unusual name when you create it
2) verify it is transferred successfully
3) verify it is going in the right location by examining spfilE

4. verify that you are using the control file that you think you created in the alter database command. use the TO ‘c:\somwhere\stdby.ctl’ option of the command.