snapshot相关

1. 概述

Specify the number of days of snapshots to choose from

Entering the number of days (n) will result in the most recent

(n) days of snapshots being listed. Pressing <return> without

specifying a number lists all completed snapshots.

Enter value for num_days: 2

Listing the last 2 days of Completed Snapshots

Snap

Instance DB Name Snap Id Snap Started Level

------------ ------------ --------- ------------------ -----

orcl ORCL 4759 29 Mar 2028 17:04 1

现象：查看snapshot生成历史，发现很长一段时间都没有生成snapshot

这是一个开发数据库，经过和开发沟通，由于业务测试经常修改操作服务器系统时间。

原因分析：由于修改操作系统时间，在修改成正确的时间后，snapshot 无法自动生成

2. 解决办法

2.1 查看所有的snapshot

SQL> select snap_id,dbid from dba_hist_snapshot order by 1;

SNAP_ID DBID

---------- ----------

4752 1373768042

4753 1373768042

4754 1373768042

4755 1373768042

4756 1373768042

4757 1373768042

4758 1373768042

2.2 删掉所有的已经存在的snapshot

dbms_workload_repository.drop_snapshot_range(low_snap_id=>4752,high_snap_id=>4758,dbid=> 1373768042);

2.3 手工创建新的snapshot

exec dbms_workload_repository.create_snapshot();

2.4 修改自动收集snapshot的周期测试

收集间隔时间改为30 分钟一次。并且保留5天时间

exec dbms_workload_repository.modify_snapshot_settings(interval=>30, retention=>5*24*60);

2.5 查看收集周期

SQL> select * from dba_hist_wr_control;

DBID SNAP_INTERVAL RETENTION TOPNSQL

---------- --------------------------------------------------------------------------- --------------------------------------------------------------------------- ----------

1373768042 +00000 00:30:00.0 +00008 00:00:00.0 DEFAULT

2.6 查看新生成的snapshot

SQL> select snap_id,dbid,BEGIN_INTERVAL_TIME from dba_hist_snapshot;

SNAP_ID DBID BEGIN_INTERVAL_TIME

---------- ---------- ---------------------------------------------------------------------------

4759 1373768042 29-MAR-17 04.51.37.190 PM

4760 1373768042 29-MAR-17 05.04.47.970 PM

2.7 正常生成AWR报告

SQL> @ $ORACLE_HOME/rdbms/admin/awrrpti.sql

Specify the Report Type

~~~~~~~~~~~~~~~~~~~~~~~

Would you like an HTML report, or a plain text report?

Enter 'html' for an HTML report, or 'text' for plain text

Defaults to 'html'

Enter value for report_type:

Type Specified: html

Instances in this Workload Repository schema

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

DB Id Inst Num DB Name Instance Host

------------ -------- ------------ ------------ ------------

* 1373768042 1 ORCL orcl ceshi

Enter value for dbid: 1373768042

Using 1373768042 for database Id

Enter value for inst_num: 1

Using 1 for instance number

Specify the number of days of snapshots to choose from

Entering the number of days (n) will result in the most recent

(n) days of snapshots being listed. Pressing without

specifying a number lists all completed snapshots.

Enter value for num_days: 2

Listing the last 2 days of Completed Snapshots

Snap

Instance DB Name Snap Id Snap Started Level

---

orcl ORCL 4759 29 Mar 2017 17:04 1

          4760 29 Mar 2017 17:13 1

Specify the Begin and End Snapshot Ids

Enter value for begin_snap: