View, modify the Oracle character set, view the Oracle version

1. View the database character set

The database server character Set select * from Nls_database_parameters, which is derived from props$, is the character set representing the database.
　　
Client Character Set Environment select * from Nls_instance_parameters, which originates from V$parameter,
　　
Represents the setting of the client's character set, which may be a parameter file, an environment variable, or a registry
　　
Session Character Set Environment select * from Nls_session_parameters, which originates from V$nls_parameters, represents the session's own settings, which may be the session's environment variable or alter session completion, If the session does not have a special setting, it will be consistent with nls_instance_parameters.
　　
The client's character set requires consistency with the server to correctly display non-ASCII characters for the database. If multiple settings exist, ALTER session> environment variable > registry > Parameter File
　　
Character set requirements are consistent, but language settings can be different, language settings are recommended in English. If the character set is ZHS16GBK, then Nls_lang can be AMERICAN_AMERICA.ZHS16GBK.

2. Modify the character set
8i or later can be modified by ALTER DATABASE to modify the character set, but also limited to subsets to superset, it is not recommended to modify the props$ table, will likely lead to serious errors.
　　
Startup Nomount;
Alter database Mount exclusive;
Alter system enable restricted session;
Alter system set job_queue_process=0;
Alter database open;
Alter database character Set ZHS16GBK;

3. How to view database version

SELECT * FROM V$version

Contains version information, core version information, bit information (32-bit or 64-bit), etc.

As for the bit information, on the Linux/unix platform, you can view it through file, as

File $ORACLE _home/bin/oracle

View, modify the Oracle character set, view the Oracle version