Can nls_characterset be changed after the oracle server being installed?
I took the default install of Oracle server and the nls_characterset is set to 'WE8ISO8859P1'. Now I need to make my Oracle server to support Unicode, so how can I change the nls_characterset to 'NTF8'? I heard it can only be changed when install the oracle server.
Also, do all the instances on an Oracle server have to use the same nls_characterset? Can we assign different ones for different instance?
According to the doc you referred to me, if the new character set is not the strict superset of the existing character set, then more than likely we will need to do a full export/import to convert all the data to the new characterset.
However, consider we have an Oracle server set up with the nls_characteret set to 'WE8ISO8859P1'. There are some data on this server already and they will only be in English. Now we need to add another database to this Oracle server for the newly introduced application, and this new database needs to support unicode.
Obviously, we need to set the NLS_Characterset to 'UTF8' to satisfy the new application's requirement. However, do we need to do a full export/import for the other application's data even if they don't need to support unicode(will only be in English)?
Also, could different instances on the same Oracle server have different nls_characterset?