Oracle Character set query and modification

The character set consists of the following four types:

1. Oracle Service-side character set

Select *  from Nls_database_parameters;

2. Oracle Server Registration Character Set

Hkey_local_machine/software/oracle/key_oradb11g_home1
Nls_lang for character sets

3. Oracle Client Character Set

Select *  from Nls_instance_parameters;

4. Session Character Set

Select *  from Nls_session_parameters;

Setting the session character set based on the service-side character set (nls_database_parameters)
SET nls_lang=nls_language_nls_territory. Nls_characterset

Example: SET Nls_lang=american_america. Al32utf8

Oracle Character set query and modification