【转自mos文章】使用单条sql来查询出awr中的syatem statistics

使用单条sql来查询出awr中的syatem statistics

参考自：
How to monitor system statistics from AWR snapshot by single SQL? (Doc ID 1320445.1)

适用于：
Oracle Server - Enterprise Edition - Version: 10.2.0.1 and later   [Release: 10.2 and later ]
Information in this document applies to any platform.

目标：
SQL to monitor the latest changes of system statistics gathered by Automatic Workload Repository.

The following statistics are included. 

'redo size'
'physical reads'
'physical writes'
'session logical reads'
'user calls',
'parse count (hard)'
'gcs messages sent'
'ges messages sent'
'gc cr blocks received'
'gc current blocks received'

解决方案：

This SQL outputs the average value (per hours) between the latest two AWR snapshots.

col STAT_NAME for a30
with snap_shot as
(
select  begin_time,SNAP_ID,rank from (
select trunc(BEGIN_INTERVAL_TIME,'MI') begin_time,SNAP_ID,rank() over (order by snap_id desc) as rank from DBA_HIST_SNAPSHOT
) where rank<3
),
new as
(select * from snap_shot where rank = 1),
old as
(select * from snap_shot where rank = 2)
select stat1.STAT_NAME,stat2.value-stat1.value value,(new.begin_time-old.begin_time)*24 duration_in_hour,
    (stat2.value-stat1.value)/((new.begin_time-old.begin_time)*24) value_per_hour
 from DBA_HIST_SYSSTAT stat1, DBA_HIST_SYSSTAT stat2,new,old
where stat1.snap_id=old.snap_id
  and stat2.snap_id=new.snap_id
  and stat1.STAT_NAME=stat2.STAT_NAME
  and stat1.STAT_NAME in ('redo size','physical reads','physical writes','session logical reads','user calls',
  'parse count (hard)','gcs messages sent','ges messages sent','gc cr blocks received','gc current blocks received')
  order by stat1.STAT_NAME;

 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Sample Output:

SQL> col STAT_NAME for a30
SQL> with snap_shot as
  2  (
  3  select begin_time,SNAP_ID,rank from (
  4  select trunc(BEGIN_INTERVAL_TIME,'MI') begin_time,SNAP_ID,rank() over (order by snap_id desc) as rank from DBA_HIST_SNAPSHOT
  5  ) where rank<3
  6  ),
  7  new as
  8  (select * from snap_shot where rank = 1),
  9  old as
 10  (select * from snap_shot where rank = 2)
 11  select stat1.STAT_NAME,stat2.value-stat1.value value,(new.begin_time-old.begin_time)*24 duration_in_hour,
 12  (stat2.value-stat1.value)/((new.begin_time-old.begin_time)*24) value_per_hour
 13  from DBA_HIST_SYSSTAT stat1, DBA_HIST_SYSSTAT stat2,new,old
 14  where stat1.snap_id=old.snap_id
 15  and stat2.snap_id=new.snap_id
 16  and stat1.STAT_NAME=stat2.STAT_NAME
 17  and stat1.STAT_NAME in ('redo size','physical reads','physical writes','session logical reads','user calls',
 18  'parse count (hard)','gcs messages sent','ges messages sent','gc cr blocks received','gc current blocks received')
 19  order by stat1.STAT_NAME;

STAT_NAME                           VALUE DURATION_IN_HOUR VALUE_PER_HOUR
------------------------------ ---------- ---------------- --------------
gc cr blocks received                   0                1              0
gc current blocks received              0                1              0
gcs messages sent                       0                1              0
ges messages sent                       0                1              0
parse count (hard)                      0                1              0
physical reads                          7                1              7
physical writes                       377                1            377
redo size                          730992                1         730992
session logical reads               16159                1          16159
user calls                             38                1             38

10 rows selected.

SQL>