想通过 DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS 来修改AWR snapshot 保留的时间，但是调整的时候遇到ORA-13541错误
过程如下：
C:\Users\aaaa>sqlplus yang/yang as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on 星期四 8月 4 20:51:28 2011
Copyright (c) 1982, 2010, Oracle. All rights reserved.
连接到:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
sys@rac1>col SNAP_INTERVAL for a20
sys@rac1>col RETENTION for a20
检查当前系统的保留时间为8天,1小时采样一次.
sys@rac1>select * from dba_hist_wr_control;
DBID SNAP_INTERVAL RETENTION TOPNSQL
---------- -------------------- -------------------- ----------
1284003062 +00000 01:00:00.0 +00008 00:00:00.0 DEFAULT
sys@rac1>exec DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(interval=>30,retention => 24*60 );
BEGIN DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(interval=>30,retention => 24*60 ); END;
*
第 1 行出现错误:
ORA-13541: 系统移动窗口基线大小 (691200) 大于保留时间 (86400)
ORA-06512: 在 "SYS.DBMS_WORKLOAD_REPOSITORY", line 174
ORA-06512: 在 "SYS.DBMS_WORKLOAD_REPOSITORY", line 222
ORA-06512: 在 line 1
这里 691200 ，86400都是以秒为单位的。
SQL> !oerr ora 13541
13541, 00000, "system moving window baseline size (%s) greater than retention (%s)"
// *Cause: The system moving window baseline size must be less than the
// retention setting. The specified window size or retention
// violate this.
// *Action: Check the moving window baseline size or retention.
sys@rac1>select 691200/60/60/24 from dual;
691200/60/60/24
---------------
8
sys@rac1>select 86400/(24*24*60) from dual;
86400/(24*24*60)
----------------
2.5
查看系统的当前的MOVING_WINDOW_SIZE
sys@rac1> select dbid,baseline_name,baseline_type,moving_window_size from dba_hist_baseline;
DBID BASELINE_NAME BASELINE_TYPE MOVING_WINDOW_SIZE
---------- --------------- ------------- ------------------
1284003062 SYSTEM_MOVING_WINDOW MOVING_WINDOW 8
修改其大小 为2 ，即两天。
sys@rac1> exec dbms_workload_repository.modify_baseline_window_size(2);
PL/SQL 过程已成功完成。
sys@rac1>exec DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(interval=>30,retention => 5*24*60 );
PL/SQL 过程已成功完成。
sys@rac1>select * from dba_hist_wr_control;
DBID SNAP_INTERVAL RETENTION TOPNSQL
---------- -------------------- -------------------- ----------
1284003062 +00000 00:30:00.0 +00005 00:00:00.0 DEFAULT
sys@rac1>exec DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(interval=>30,retention => 2*24*60 );
PL/SQL 过程已成功完成。
sys@rac1>select * from dba_hist_wr_control;
DBID SNAP_INTERVAL RETENTION TOPNSQL
---------- -------------------- -------------------- ----------
1284003062 +00000 00:30:00.0 +00002 00:00:00.0 DEFAULT
sys@rac1>