select b.sql_text, 
a.buffer_gets, 
a.executions, 
a.buffer_gets/decode(a.executions , 0 , 1 , a.executions), 
c.username 
from V$sqlarea a, 
v$sqltext_with_newlines b, 
dba_users c 
where a.parsing_user_id = c.user_id 
and a.address = b.address 
order by a.buffer_gets desc , b.piece 
; 

select distinct ss from (
select a.sql_text ss, 
a.buffer_gets, 
a.executions, 
a.buffer_gets/decode(a.executions , 0 , 1 , a.executions), 
c.username 
from V$sqlarea a, 
v$sqltext_with_newlines b, 
dba_users c 
where a.parsing_user_id = c.user_id 
and a.address = b.address 
and  to_char(a.LAST_LOAD_TIME,'yyyy-MM-dd hh:mi:ss')  > '2011-01-25 12:00:00'
order by a.disk_reads  desc , b.piece )

select distinct ss from (
select a.sql_text ss
from V$sqlarea a, 
v$sqltext_with_newlines b, 
dba_users c 
where a.parsing_user_id = c.user_id 
and a.address = b.address 
order by a.buffer_gets desc , b.piece ); 

select b.sql_text, 
a.disk_reads, 
a.executions, 
a.disk_reads/decode(a.executions , 0 , 1 , a.executions), 
c.username 
from v$sqlarea a, 
v$sqltext_with_newlines b, 
dba_users c 
where a.parsing_user_id = c.user_id 
and a.address = b.address 
order by a.disk_reads desc , b.piece 
;