ORACLE 清理SYSAUX表空间

ORACLE 清理SYSAUX表空间

在数据库检查中发现SYSAUX表空间占用过大，SYSAUX是ORACLE10G开始提供的功能，用于数据库为SYSTEM表空间减负。

用以下语句查出相应的表空间值

select
a.tablespace_name,trunc(sum(a.bytes)/1024/1024/1024,2) total,
trunc(sum(a.bytes)/1024/1024/1024 - sum(b.bytes)/1024/1024/1024,2) used,
trunc(sum(b.bytes)/1024/1024/1024,2) free,
to_char(trunc((sum(a.bytes)/1024/1024/1024-sum(b.bytes)/1024/1024/1024)/(sum(a.bytes)/1024/1024/1024),4)*100)||'%' pused,
to_char(trunc((sum(b.bytes)/1024/1024/1024)/(sum(a.bytes)/1024/1024/1024),4)*100)||'%' pfree
from (select sum(bytes) bytes,tablespace_name from dba_data_files group by tablespace_name) a,(select sum(bytes) bytes,tablespace_name from dba_free_space group by tablespace_name) b
where a.tablespace_name=b.tablespace_name(+)
group by a.tablespace_name;

查出表空SYSAUX占用率过高

SYSAUX共13.84G 其使用率95%

通过以下语句查出什么使用这么多空间

SELECT occupant_name "Item",
space_usage_kbytes / 1048576 "Space Used (GB)",
schema_name "Schema",
move_procedure "Move Procedure"
FROM v$sysaux_occupants
ORDER BY 2 desc;

 从上图可以看到其中AWR用了11G空间

查看下AWR统计数的保存天数

select dbms_stats.get_stats_history_retention from dual; 

 

 通过 select dbid, min(snap_id),max(snap_id) from dba_hist_snapshot group by dbid;

查出相应的DBID和SNAP_ID,

• 清空上一个dbid下的所有snapshot

exec dbms_workload_repository.drop_snapshot_range(29737,29943,310691130);

等待太久了‘

为了加快清除速实施以下操作

查找到那些占用sysaux表空间的基表，按照大小进行排序

select * from (select segment_name,PARTITION_NAME,segment_type,bytes/1024/1024 from dba_segments where tablespace_name='SYSAUX' order by 4 desc) where rownum<=10;

查出以下内容

备份基表WRH$ACTIVE_SESSION_HISTOR,WRH$_SQLSTAS,WRH$_EVENT_HISTOGRAM

create table WRH$_ACTIVE_SESSION_HISTORY0926 as select * from WRH$_ACTIVE_SESSION_HISTORY;
create table WRH$_SQLSTAT0926 as select * from WRH$_SQLSTAT;
create table WRH$_EVENT_HISTOGRAM0926 as select * from WRH$_EVENT_HISTOGRAM;
create table WRH$_LATCH0926 as select * from WRH$_LATCH;

清除相应基表数据

truncate  table  WRH$_ACTIVE_SESSION_HISTORY;
truncate  table  WRH$_EVENT_HISTOGRAM;
truncate  table  WRH$_SQLSTAT;
truncate  table  WRH$_LATCH_MISSES_SUMMARY;
truncate  table  WRH$_LATCH;
truncate  table  WRH$_SYSSTAT;
truncate  table  WRH$_SEG_STAT;
truncate  table  WRH$_PARAMETER;
truncate  table  WRH$_SYSTEM_EVENT;
truncate  table  WRH$_SQL_PLAN;
truncate  table  WRH$_DLM_MISC;
truncate  table  WRH$_SERVICE_STAT;
truncate  table  WRH$_TABLESPACE_STAT;
truncate  table  WRH$_ROWCACHE_SUMMARY;
truncate  table  WRH$_MVPARAMETER;