The top 10 first hungriest queries

SELECT Disk_Reads DiskReads, Executions, SQL_ID, SQL_Text SQLText,
   SQL_FullText SQLFullText
FROM
(
   SELECT Disk_Reads, Executions, SQL_ID, LTRIM(SQL_Text) SQL_Text,
      SQL_FullText, Operation, Options,
      Row_Number() OVER
         (Partition By sql_text ORDER BY Disk_Reads * Executions DESC)
         KeepHighSQL
   FROM
   (
       SELECT Avg(Disk_Reads) OVER (Partition By sql_text) Disk_Reads,
          Max(Executions) OVER (Partition By sql_text) Executions,
          t.SQL_ID, sql_text, sql_fulltext, p.operation,p.options
       FROM gv$sql t, gv$sql_plan p
       WHERE t.hash_value=p.hash_value AND p.operation='TABLE ACCESS'
       AND p.options='FULL' AND p.object_owner NOT IN ('SYS','SYSTEM')
       AND t.Executions > 1
   )
   ORDER BY DISK_READS * EXECUTIONS DESC
)
WHERE KeepHighSQL = 1
AND rownum <=10;

Linux: Display the usage of processors and memory without provisioning values (the real usage)

Procs (two alternatives):

top -bn1 | grep "Cpu(s)" | sed "s/.*, *\([0-9.]*\)%* id.*/\1/" | awk '{print 100 - $1"%"}'

grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage "%"}'


Memory:
 
ps aux | awk '{sum+=$6} END {print sum / 1024}'