Oracle En Pahalı SQL'ler: v$sqlstats ile Top 20

SELECT * FROM (
  SELECT sql_id,
         executions,
         ROUND(elapsed_time / 1e6, 1) AS elapsed_sec,
         ROUND(elapsed_time / NULLIF(executions, 0) / 1e3, 2) AS avg_ms,
         ROUND(cpu_time / 1e6, 1) AS cpu_sec,
         buffer_gets, disk_reads, rows_processed
  FROM   v$sqlstats
  ORDER  BY elapsed_time DESC
) WHERE ROWNUM <= 20;