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;
来源: http://www.linuxidc.com/Linux/2019-04/158094.htm