共计 2745 个字符，预计需要花费 7 分钟才能阅读完成。
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;
更多 Oracle 相关信息见 Oracle 专题页面 https://www.linuxidc.com/topicnews.aspx?tid=12
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