How to see Database size ?

How can I see Database size in Oracle, and what are Oracle 8i
Tools.

kindly suggest please.
with kind regards,
Badri.

select sum(bytes/1024/1024) MB
from dba_data_files;

This will give you the size of all datafiles.

Is this what you meant?

Add to this the size (in megabytes) of your redo logs:

select sum(bytes)/1024/1024 from v$log;