几个有用的oracle dba_hist_*查询语句

耗CPU最多的10条语句

select * from

   (select

    s.SQL_ID,

    sum(s.CPU_TIME_DELTA),

    sum(s.DISK_READS_DELTA),

    count(*)

    from DBA_HIST_SQLSTAT s

   group by s.SQL_ID

   order by sum(s.CPU_TIME_DELTA) desc

   )

where rownum < 11

/

最近7天，指定时间段（8:00-16:00）最消耗CPU的10条语句

select * from

   (select

      s.SQL_ID,

      sum(s.CPU_TIME_DELTA),

      sum(s.DISK_READS_DELTA),

      count(*)

    from DBA_HIST_SQLSTAT s, DBA_HIST_SNAPSHOT p

    where 1=1

     and s.SNAP_ID = p.SNAP_ID

     and EXTRACT(HOUR FROM p.END_INTERVAL_TIME) between 8 and 16

     and p.END_INTERVAL_TIME between SYSDATE-7 and SYSDATE

    group by s.SQL_ID

    order by sum(s.CPU_TIME_DELTA) desc

   )

where rownum < 11

/

可以进一步关联DBA_HIST_SQLTEXT视图得到详细的SQL语句

select * from

   (select

    s.SQL_ID, s.SQL_TEXT

    sum(s.CPU_TIME_DELTA),

    sum(s.DISK_READS_DELTA),

    count(*)

   from DBA_HIST_SQLSTAT s, DBA_HIST_SNAPSHOT p, DBA_HIST_SQLTEXT t

   where 1=1

    and s.SNAP_ID = p.SNAP_ID

    and s.SQL_ID = t.SQL_ID

    and EXTRACT(HOUR FROM p.END_INTERVAL_TIME) between 8 and 16

    and t.COMMAND_TYPE != 47 –- Exclude PL/SQL blocks from output

    and p.END_INTERVAL_TIME between SYSDATE-7 and SYSDATE

   group by s.SQL_ID

   order by sum(s.CPU_TIME_DELTA) desc

   )

where rownum < 11

/

分析指定SQL语句各版本执行计划的资源消耗情况

select st.SQL_ID,

   st.PLAN_HASH_VALUE,

   sum(st.EXECUTIONS_DELTA) EXECUTIONS,

   sum(st.ROWS_PROCESSED_DELTA) CROWS,

   trunc(sum(st.CPU_TIME_DELTA)/1000000/60) CPU_MINS,

   trunc(sum(st.ELAPSED_TIME_DELTA)/1000000/60)  ELA_MINS

from DBA_HIST_SQLSTAT st

where st.SQL_ID in (‘&1′)

group by st.SQL_ID , st.PLAN_HASH_VALUE

order by st.SQL_ID, CPU_MINS;

分析对比SQL语句在不同执行计划中的执行情况

SELECT st2.SQL_ID,

   st2.PLAN_HASH_VALUE,

   st_long.PLAN_HASH_VALUE l_PLAN_HASH_VALUE,

   st2.CPU_MINS,

   st_long.CPU_MINS l_CPU_MINS,

   st2.ELA_MINS,

   st_long.ELA_MINS l_ELA_MINS,

   st2.EXECUTIONS,

   st_long.EXECUTIONS l_EXECUTIONS,

   st2.CROWS,

   st_long.CROWS l_CROWS,

   st2.CPU_MINS_PER_ROW,

   st_long.CPU_MINS_PER_ROW l_CPU_MINS_PER_ROW

FROM

   (SELECT st.SQL_ID,

     st.PLAN_HASH_VALUE,

     SUM(st.EXECUTIONS_DELTA) EXECUTIONS,

     SUM(st.ROWS_PROCESSED_DELTA) CROWS,

     TRUNC(SUM(st.CPU_TIME_DELTA)                                         /1000000/60) CPU_MINS ,

     DECODE( SUM(st.ROWS_PROCESSED_DELTA), 0 , 0 , (SUM(st.CPU_TIME_DELTA)/1000000/60)/SUM(st.ROWS_PROCESSED_DELTA) ) CPU_MINS_PER_ROW ,

     TRUNC(SUM(st.ELAPSED_TIME_DELTA)                                     /1000000/60) ELA_MINS

   FROM DBA_HIST_SQLSTAT st

   WHERE 1                     =1

   AND ( st.CPU_TIME_DELTA    !=0

   OR st.ROWS_PROCESSED_DELTA !=0)

   GROUP BY st.SQL_ID,

     st.PLAN_HASH_VALUE

   ) st2,

   (SELECT st.SQL_ID,

     st.PLAN_HASH_VALUE,

     SUM(st.EXECUTIONS_DELTA) EXECUTIONS,

     SUM(st.ROWS_PROCESSED_DELTA) CROWS,

     TRUNC(SUM(st.CPU_TIME_DELTA)                                         /1000000/60) CPU_MINS ,

     DECODE( SUM(st.ROWS_PROCESSED_DELTA), 0 , 0 , (SUM(st.CPU_TIME_DELTA)/1000000/60)/SUM(st.ROWS_PROCESSED_DELTA) ) CPU_MINS_PER_ROW ,

     TRUNC(SUM(st.ELAPSED_TIME_DELTA)                                     /1000000/60) ELA_MINS

   FROM DBA_HIST_SQLSTAT st

   WHERE 1                                         =1

   AND ( st.CPU_TIME_DELTA                        !=0

   OR st.ROWS_PROCESSED_DELTA                     !=0)

   HAVING TRUNC(SUM(st.CPU_TIME_DELTA)/1000000/60) > 10

   GROUP BY st.SQL_ID,

     st.PLAN_HASH_VALUE

   ) st_long

WHERE 1                                                                            =1

AND st2.SQL_ID                                                                     = st_long.SQL_ID

AND st_long.CPU_MINS_PER_ROW/DECODE(st2.CPU_MINS_PER_ROW,0,1,st2.CPU_MINS_PER_ROW) > 2

ORDER BY l_CPU_MINS DESC,

   st2.SQL_ID,

   st_long.CPU_MINS DESC,

   st2.PLAN_HASH_VALUE;