Oracle server version

[Steffen Goeldner]

I'm searching for a reliable way to get the version number
of an Oracle server.
I collected some alternatives:

 select * from v$version;

 select * from PRODUCT_COMPONENT_VERSION;

 set serveroutput on
 declare
   v varchar2(255);
   c varchar2(255);
 begin
   dbms_utility.db_version( v, c );
   dbms_output.put_line( v );
   dbms_output.put_line( c );
 end;
 /

 select dbms_utility.port_string from dual;

For Oracle8 results, see e.g.:

  <http://www.xray.mpe.mpg.de/mailing-lists/dbi/2002-01/msg00525.html>

Unfortunately, I have no Oracle7 available. Would somebody
be kind enough to provide the results for an Oracle7 server?

Many thanks in advance,
Steffen Goeldner