理论上AWR数据应当根据保留时间,自动清理,但是实际上,经常碰到这样的:

col segment_name for a32;
set linesize 500;
set pagesize 500;
with t1 as (
select round(sum(bytes)/1024/1024) MB,segment_name from dba_segments where owner='SYS' 
group by segment_name
order by 1 desc )
select * from t1 where rownum<16;

然后WRH$开头的几个表占十几个G的情况,也就是AWR数据并没有完全被清理掉,检查策略一切正常:

 SQL> select INSTANCE_NUMBER, min(SAMPLE_TIME), max(SAMPLE_TIME) from 
WRH$_ACTIVE_SESSION_HISTORY group by INSTANCE_NUMBER;  2  

INSTANCE_NUMBER MIN(SAMPLE_TIME)                                                            MAX(SAMPLE_TIME)
---------------  -------------------------            --------------------------------------------------
              1 25-MAY-16 08.14.48.613 PM                                                   28-MAR-18 08.56.02.944 AM

SQL>  select snap_interval,retention from dba_hist_wr_control;

SNAP_INTERVAL                                                               RETENTION
------------------------------------ ---------------------------------------------------------------------------
+00000 01:00:00.0                                                           +00008 00:00:00.0

select min(snap_id),max(snap_id) ,dbid from sys.WRH$_EVENT_HISTOGRAM group by dbid;

MOS查一下BUG号14084247,从 11.2.0.3之后几乎都有这个问题,并且打了14084247 之后,貌似也不能解决,MOS又发一篇文章,手动清理,DOCID387914.1,步骤如下:
1检查分区情况

SELECT owner,
  segment_name,
  partition_name,
  segment_type,
  bytes/1024/1024/1024 Size_GB
FROM dba_segments
WHERE segment_name='WRH$_ACTIVE_SESSION_HISTORY';

2 修改隐含参数:
alter session set "_swrf_test_action" = 72;
3 再次检查分区情况
4 统计各个WRH表的最大,最小snap_id

set serveroutput on 
declare 
CURSOR cur_part IS 
SELECT partition_name from dba_tab_partitions 
WHERE table_name = 'WRH$_ACTIVE_SESSION_HISTORY'; 

query1 varchar2(200); 
query2 varchar2(200); 

TYPE partrec IS RECORD (snapid number, dbid number); 
TYPE partlist IS TABLE OF partrec; 

Outlist partlist; 
begin 
dbms_output.put_line('PARTITION NAME SNAP_ID DBID'); 
dbms_output.put_line('--------------------------- ------- ----------'); 

for part in cur_part loop 
query1 := 'select min(snap_id), dbid from sys.WRH$_ACTIVE_SESSION_HISTORY partition ('||part.partition_name||') group by dbid'; 
execute immediate query1 bulk collect into OutList; 

if OutList.count > 0 then 
for i in OutList.first..OutList.last loop 
dbms_output.put_line(part.partition_name||' Min '||OutList(i).snapid||' '||OutList(i).dbid); 
end loop; 
end if; 

query2 := 'select max(snap_id), dbid from sys.WRH$_ACTIVE_SESSION_HISTORY partition ('||part.partition_name||') group by dbid'; 
execute immediate query2 bulk collect into OutList; 

if OutList.count > 0 then 
for i in OutList.first..OutList.last loop 
dbms_output.put_line(part.partition_name||' Max '||OutList(i).snapid||' '||OutList(i).dbid); 
dbms_output.put_line('---'); 
end loop; 
end if; 

end loop; 
end; 
/

5 删除不需要的数据

DBMS_WORKLOAD_REPOSITORY.DROP_SNAPSHOT_RANGE(
low_snap_id IN NUMBER,
high_snap_id IN NUMBER
dbid IN NUMBER DEFAULT NULL);

6 运行 @?/rdbms/admin/awrinfo.sql再次检查下
7 最后建议重启一下MMON刷新:

alter system set "_swrf_mmon_flush"=false; 
alter system set "_swrf_mmon_flush"=true;