cpu time sql

SELECT cpu_time/1000000,executions,cpu_time/executions/1000000,substr(sql_text,1,255) FROM ( SELECT V$SQLAREA.CPU_TIME,V$SQLAREA.EXECUTIONS,NVL(V$SQL.SQL_TEXT,V$SQLAREA.SQL_TEXT) SQL_TEXT FROM V$SQLAREA,V$SQL WHERE V$SQLAREA.HASH_VALUE=V$SQL.HASH_VALUE(+) AND V$SQLAREA.EXECUTIONS<>0 ORDER BY V$SQLAREA.cpu_time DESC) a WHERE ROWNUM<10