NLS_LENGTH_SEMANTICS

Today I had a problem in importing a dump file into a Oracle schema. I got a strange error... I started my debugging, I tried to import the dump file with zero objects in the schema and I was successful in importing the dump file. Then I tried importing the dump file with tables already created in the schema and this time the import failed. The problem was with the NLS_LENGTH_SEMANTICS parameter, it was set to Byte, so the tables got created with Bytes, but the actual import file contains tables with Char. I changed the parameter from BYTES to CHAR... SQL> alter system set NLS_LENGTH_PARAMETER = CHAR Then restarted the database and the import worked properly... It is better to have the NLS_LENGTH_SEMANTICS as CHAR. Chk out the below link for more info...

URL: http://www.oracle.com/technology/oramag/oracle/03-mar/o23sql.html