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Showing posts from May, 2011

How to change SYS / SYSTEM password

1) Backup the pwd file or folder :$ORACLE_HOME/dbs/orapw$ORACLE_SID 2) Run the below command as Oracle User   give the correct path and the file name...        orapwd file=<path>orapwSID password=oracle entries=5 3) Login sys as sysdba and check the new password. Some Info........... Create a new password file: orapwd file=orapwSID password=oracle entries=5 If the password file already exists: orapwd file=orapwSID password=oracle entries=5 FORCE=Y Default location and file name: The default location for the password file is:$ORACLE_HOME/dbs/orapw$ORACLE_SID on Unix and %ORACLE_HOME%\database\PWD%ORACLE_SID%.ora on Windows.

Scheduler Jobs - Error!!!

When trying to execute a scheduled job you may get below error sometimes in Oracle EM. ERROR java.sql.SQLException: ORA-02800: Requests timed out ORA-06512: at "SYS.DBMS_ISCHED", line 150 ORA-06512: at "SYS.DBMS_SCHEDULER", line 441 ORA-06512: at line 2  This is a bug in Oracle. Most of the times, restarting Oracle database may fix the issue. Basically, an existing bug needs the oracle database restarts in a regular basis. Restarting oracle database will flushes the database buffer cache.

Initialization parameter JOB_QUEUE_PROCESSES

The initialization parameter JOB_QUEUE_PROCESSES represents the maximum number of job queue processes that can concurrently run on an instance. However, we should not assume that all job queue processes are available for job execution. The coordinator process is not started if the initialization parameter JOB_QUEUE_PROCESSES is set to 0.  The maximum number of processes that can be specified is 1000. The  JOB_QUEUE_PROCESSES  initialization parameter is dynamic and it can be modified by an  ALTER SYSTEM  statement.  ALTER SYSTEM SET JOB_QUEUE_PROCESSES = 20;

Get the value which is before the MAX value (Use of RANK function)

When come to a scenario where we want to get the value which is just before the MAX value we cant use rownum.It will work for only 1st row. But we can use RANK function to rank the ordered values and then select the desired rank.In this case rank 2. Eg: select UserID,Value from (select UserID,Value, rank() over (partition by UserID order by Value Desc) RNK from t) where rnk=2