The NLS_CHARACTERSET of an Oracle database defines what characters can be stored in the database using the CHAR, VARCHAR2, LONG and CLOB datatypes. This blog gives a quick overview of a method to change the database character set or to check before migrating data between databases with a different NLS_CHARACTERSET.
If you change character sets there is a possibility that characters that you currently use are not defined in the new character set or that the current setup is not correctly used and therefore you could lose data when changing the NLS_CHARACTERSET.
In previous blog “2014-06 – Database Character Set Scanner”, we addressed how to install a great Oracle tool called CSSCAN. Always check data migration by using the Character Set Scanner (CSSCAN) before making any changes to your character set.