How can we check the size of database growth? I needed to know this while generating a report for management regarding DB size.

Now here a little script that will retrieve the size of database monthly. For execution of this script you will need to have select privilege on sys.v_$datafile view. Following query will retrieve results based on months, however you can easily tweak this query for creation_time column to get any type of extracts.

Script

select to_char(creation_time, 'YYYY Month') "Month",
    sum(bytes)/1024/1024 "Growth in MB"
    from sys.v_$datafile
    where creation_time > SYSDATE-365
    group by to_char(creation_time, 'YYYY Month');

Result

Month          Growth in MB
-------------- ------------
2010 December             2
2010 November            100