Why Oracle DBA_TEMP_FILES view Bytes Column is NULL: How to Drop, Shrink Offline / Online Temp File

Some Facts on Oracle Tempfiles:

If the database tempfile is in offline status then the bytes column of the dba_temp_files will be null. If the file system of the temporary file is having some problem then the corresponding tempfile status will move to offline

Oracle 11g Database Startup Failed: /dev/shm and ORA-00845: MEMORY_TARGET not supported on this system

Error Description:

I have modified or increased the value for the parameter MEMORY_TARGET and then Oracle 11g database startup failed with following error.

SQL> startup

ORA-00845: MEMORY_TARGET not supported on this system

Datapump IMPDP Partition_Options = MERGE , DEPARTITION Examples

Partition_Options parameter is available with data pump impdp utility.  This parameter determines how the partitions available in the export dump are handled in the import operation.

Duplicate Command Failed: RMAN-05001: auxiliary filename %s conflicts with a file used by the target database

Error Description:

RMAN Duplicate database command failed with RMAN-05001 error message

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 21/10/2012 23:09:54
RMAN-05501: aborting duplication of target database

OC4J Connection Pool Error Message: java.sql.SQLException: ORA-01017: invalid username/password; logon denied

Error Description:

OC4J connection pool configuration testing to Oracle 11g database is giving following error.

OC4J Error message: Exception occurred testing connection. Exception: java.sql.SQLException: ORA-01017: invalid username/password; logon denied 

Fix ORA-02032: clustered tables cannot be used before the cluster index is built

Error Description:

Insert SQL statement fails with following error message.

SQL> insert into emp values (7369, 'smith', 'clerk', 7902,to_date('17-dec-1980', 'dd-mon-yyyy'), 800, null, 20);

Truncate Failed: ORA-03292: Table to be truncated is part of a cluster

Error Description:

Truncate table command failed with following error message.

SQL> TRUNCATE TABLE DEPT;

TRUNCATE TABLE DEPT

               *