Checking oracle sid and database name

Question

I want to check SID and current database name.

I am using following query for checking oracle SID

select instance from v$thread;

bu

Answer 1

I presume SELECT user FROM dual; should give you the current user

and SELECT sys_context('userenv','instance_name') FROM dual; the name of the instance

I believe you can get SID as SELECT sys_context('USERENV', 'SID') FROM DUAL;