Capture Resource intensive SQLs

I was wondering if there is a way to capture "resource intensive" SQL statements in the database without turning
the trace on.

I want avoid turning tracing on in the production database
and also avoid generating lot fo trace files.

Are there any useful SQL statements to capture "resource intensive" SQL statements?


TIA

Here are two:

------------------------------------------------------------------------
-- Purpose:to find expensive sql that may need tuning
------------------------------------------------------------------------
column load format a6 justify right
column executes format 9999999
break on load on executes

select substr(to_char(s.pct,'99.00'),2)||'%' load,
s.executions executes, p.sql_text
from
(select address, disk_reads, executions, pct,
rank() over (order by disk_reads desc) ranking
from
(select address, disk_reads, executions,
100 * ratio_to_report(disk_reads) over () pct
from v$sql
where command_type != 47)
where disk_reads > 50 * executions) s,
sys.v_$sqltext p
where s.ranking <= 5
and p.address = s.address
order by 1, s.address, p.piece
/
undefine Percent

AND

------------------------------------------------------------------------
-- Purpose: to find suspicious sql that may need tuning
------------------------------------------------------------------------column load format a6 justify right
column executes format 9999999
break on load on executes
select substr(to_char(s.pct, '99.00'), 2) || '%' load,
s.executions executes, p.sql_text
from (select address, buffer_gets, executions, pct,
rank() over (order by buffer_gets desc) ranking
from (select address, buffer_gets, executions,
100 * ratio_to_report(buffer_gets) over () pct
from sys.v$sql
where command_type != 47)
where buffer_gets > 50 * executions) s, v$sqltext p
where s.ranking <= 5
and p.address = s.address
order by 1, s.address, p.piece
/
undefine Percent