通過修改了AWR收集頻率之後（http://zxf261.blog.51cto.com/701797/762046），發現SYSAUX表空間還是佔用嚴重。
下面介紹一下如何清理SYSAUX表空間
一.清理SYSAUX下的歷史統計信息
1.將歷史統計信息保留時間設爲無限
exec dbms_stats.alter_stats_history_retention(-1);
2.truncate較大的TABLE
truncate table sys.WRI$_OPTSTAT_HISTHEAD_HISTORY;
truncate table sys.WRI$_OPTSTAT_HISTGRM_HISTORY;
3.清理歷史統計信息
exec dbms_stats.purge_stats(sysdate-101);
exec dbms_stats.purge_stats(sysdate-51);
exec dbms_stats.purge_stats(sysdate-5);
4.將歷史統計信息保留時間設爲10天
exec dbms_stats.alter_stats_history_retention(10);
5.將歷史統計信息相關的表進行MOVE
alter table sys.WRI$_OPTSTAT_HISTHEAD_HISTORY move tablespace sysaux;
alter index sys.I_WRI$_OPTSTAT_HH_OBJ_ICOL_ST rebuild online;
alter index sys.I_WRI$_OPTSTAT_HH_ST rebuild online;
alter table sys.WRI$_OPTSTAT_HISTGRM_HISTORY move tablespace sysaux;
alter index sys.I_WRI$_OPTSTAT_H_OBJ#_ICOL#_ST rebuild online;
alter index sys.I_WRI$_OPTSTAT_H_ST rebuild online;
alter table sys.WRI$_OPTSTAT_IND_HISTORY move tablespace sysaux;
alter index sys.I_WRI$_OPTSTAT_IND_OBJ#_ST rebuild online;
alter index sys.I_WRI$_OPTSTAT_IND_ST rebuild online;
alter table sys.WRI$_OPTSTAT_TAB_HISTORY move tablespace sysaux;
alter index sys.I_WRI$_OPTSTAT_TAB_OBJ#_ST rebuild online;
alter index sys.I_WRI$_OPTSTAT_TAB_ST rebuild online;
ALTER TABLE SYS.WRI$_OPTSTAT_OPR MOVE TABLESPACE SYSAUX;
ALTER TABLE SYS.WRI$_OPTSTAT_AUX_HISTORY MOVE TABLESPACE SYSAUX;
ALTER INDEX SYS.I_WRI$_OPTSTAT_AUX_ST REBUILD ONLINE;
ALTER INDEX SYS.I_WRI$_OPTSTAT_OPR_STIME REBUILD ONLINE;
6.對MOVE表的統計信息進行收集
EXEC dbms_stats.gather_table_stats(ownname => ‘SYS’,tabname => ‘WRI$_OPTSTAT_HISTHEAD_HISTORY’,cascade => TRUE);
EXEC dbms_stats.gather_table_stats(ownname => ‘SYS’,tabname => ‘WRI$_OPTSTAT_HISTGRM_HISTORY’,cascade => TRUE);
EXEC dbms_stats.gather_table_stats(ownname => ‘SYS’,tabname => ‘WRI$_OPTSTAT_IND_HISTORY’,cascade => TRUE);
EXEC dbms_stats.gather_table_stats(ownname => ‘SYS’,tabname => ‘WRI$_OPTSTAT_TAB_HISTORY’,cascade => TRUE);
EXEC dbms_stats.gather_table_stats(ownname => ‘SYS’,tabname => ‘WRI$_OPTSTAT_OPR’,cascade => TRUE);
EXEC dbms_stats.gather_table_stats(ownname => ‘SYS’,tabname => ‘WRI$_OPTSTAT_AUX_HISTORY’,cascade => TRUE);
二.清理SYAUX下的無效ASH信息
1.檢查是否有無效的ASH信息
select count(*)
from sys.wrh$_active_session_history a
where not exists (select 1
from sys.wrm$_snapshot b
where a.snap_id = b.snap_id
and a.dbid = b.dbid
and a.instance_number = b.instance_number);
2.清理無效的ASH信息
delete
from sys.wrh$_active_session_history a
where not exists (select 1
from sys.wrm$_snapshot b
where a.snap_id = b.snap_id
and a.dbid = b.dbid
and a.instance_number = b.instance_number);
3.對ASH表清理後的碎片整理
alter table sys.wrh$_active_session_history enable row movement;
alter table sys.wrh$_active_session_history shrink space cascade;
alter table sys.wrh$_active_session_history disable row movement;
4.收集碎片整理後表的統計信息
EXEC dbms_stats.gather_table_stats(ownname => ‘SYS’,tabname => ‘WRH$_ACTIVE_SESSION_HISTORY’,cascade => TRUE);
3.檢查表空間可收縮的的位置
select a.FILE#,
a.NAME,
a.BYTES / 1024 / 1024 mb,
ceil(HWM * A.BLOCK_SIZE) / 1024 / 1024 RESIZETO,
‘ALTER DATABASE DATAFILE ”’ || A.NAME || ”’ RESIZE ‘ ||
(trunc(CEIL(HWM * A.BLOCK_SIZE) / 1024 / 1024)+20) || ‘M;’ RESIZECMD
from v$datafile a,
(SELECT C.file_id, MAX(C.block_id + C.blocks – 1) HWM
FROM DBA_EXTENTS C
GROUP BY FILE_ID) B
WHERE A.FILE# = B.FILE_ID
AND a.tablespace=’SYSAUX’
ORDER BY 5;
三.SYSAUX清理後的檢查
1.清理後的無效INDEX檢查
select * from dba_indexes where status<>‘VALID’ AND STATUS<>‘N/A’;
SELECT * FROM DBA_IND_PARTITIONS WHERE STATUS<>‘USABLE’ AND STATUS<>‘N/A’;
SELECT * FROM DBA_IND_SUBPARTITIONS WHERE STATUS<>‘USABLE’;
上面語句應均無數據返回，如有則對這些INDEX進行重建
2.清理後的INDEX並行度檢查
select * from dba_indexes where degree not in (’1′,’0′,’DEFAULT’);