How to find obsolete parameters in Oracle

By querying V$OBSOLETE_PARAMETER.

If the value in column ISSPECIFIED is 'TRUE' then it is specified in the init.ora file.

select * from V$OBSOLETE_PARAMETER
where ISSPECIFIED = 'TRUE'
/

A Comparison of Oracle's DATE and TIMESTAMP Datatypes

http://blogs.ittoolbox.com/database/solutions/archives/006681.asp