snapshot相關

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

現象：查看snapshot生成歷史，發現很長一段時間都沒有生成snapshot

這是一個開發數據庫，通過和開發溝通，因爲業務測試常常修改操做服務器系統時間。

緣由分析：因爲修改操做系統時間，在修改爲正確的時間後，snapshot 沒法自動生成

2. 解決辦法

2.1 查看全部的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 刪掉全部的已經存在的snapshot

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

2.3 手工建立新的snapshot

exec dbms_workload_repository.create_snapshot();

2.4 修改自動收集snapshot的週期測試

收集間隔時間改成30 分鐘一次。而且保留5天時間

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

2.5 查看收集週期

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報告

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: