1.查询慢SQL

set echo off
set feedback off
set timing off
set verify off
set lineshow off

SELECT
        SESS_ID    ,
        EXEC_TIME  ,
        FINISH_TIME,
        N_RUNS     ,
        TRX_ID     ,
        substr(sql_text,0,20)
FROM
        V$SYSTEM_LONG_EXEC_SQLS
ORDER BY
        EXEC_TIME DESC,
        N_RUNS DESC;