Dear Gurus ! Lots of thanks to everybody who replied. I've got numerous great solutions from U - now i need to choose one among them ;-) This is a great list with genius people subscribed ! I love to belong to Oracle DBAs brotherhood. Thank U all very much & have a great day ! -----Original Message----- Sent: Wednesday, August 15, 2001 5:02 PM To: Multiple recipients of list ORACLE-L Yes, so the maximum is 3, between 12:25 and 12:30. To explicitly show the maximum (and a little histogram) you could amend it as follows: - declare l_count pls_integer := 0; l_max_count pls_integer := 0; begin for rec in ( select call_start time, 1 incr from table union all select call_end time, -1 incr from table order by 1 ) loop l_count := l_count + rec.incr; if( l_count > l_max_count ) then l_max_count := l_count; end if; dbms_output.put_line( to_char(rec.time) || ' - ' || l_count || ' ' || lpad('*',l_count) ) end loop; dbms_output.put_line( 'Maximum concurrent calls = ' || to_char(l_max_count) ); end; Regards David Lord > -----Original Message----- > From: Thomas, Kevin [mailto:[EMAIL PROTECTED]] > Sent: 15 August 2001 15:07 > To: Multiple recipients of list ORACLE-L > Subject: RE: An SQL question , not easy ;-) > > > David, > > Here's the output from your suggestion based on a table > with the following rows; > > CALL_START CALL_END > ----------------- ----------------- > 01-AUG-2001 12:10 01-AUG-2001 12:40 > 01-AUG-2001 12:15 01-AUG-2001 12:30 > 01-AUG-2001 12:25 01-AUG-2001 12:55 > 01-AUG-2001 12:45 01-AUG-2001 12:47 > > --------------------- > > 01-AUG-2001 12:10 - 1 > 01-AUG-2001 12:15 - 2 > 01-AUG-2001 12:25 - 3 > 01-AUG-2001 12:30 - 2 > 01-AUG-2001 12:40 - 1 > 01-AUG-2001 12:45 - 2 > 01-AUG-2001 12:47 - 1 > 01-AUG-2001 12:55 - 0 > > > -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Lord, David - C&S INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Andrey Bronfin INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).