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Oracle10gR2 New Feature:Generate ASH Reports
作者：eygle | 【转载请注出处】|【云和恩墨 领先的zData数据库一体机 | zCloud PaaS云管平台 | SQM SQL审核平台 | ZDBM 数据库备份一体机】
链接：https://www.eygle.com/archives/2005/09/oracle10gr2_ash_reports.html
在Oracle10gR1中,Oracle引入了ASH的概念。在Oracle10gR2中，Oracle进一步强化了ASH的功能，增加了report能力。链接：https://www.eygle.com/archives/2005/09/oracle10gr2_ash_reports.html
ASH采样的是一段时间内系统内活动session的等待信息，通过这些信息，可以获得top wait events, top SQL, top SQL command types,top sessions等等重要信息。
Oracle通过ASH Report可以对特定的时间段进行分析，可以精确到天、小时或者分钟。
ashrpt类似statspack的功能，通过报表把采集的数据直观的展现出来。其本质仍然是得益于ASH的强大功能。
我们简单看一下v$active_session_history记录的历史信息:
SQL> select sample_id,sample_time,event from v$active_session_history
2 where rownum <20;
SAMPLE_ID SAMPLE_TIME EVENT
---------- ------------------------------ --------------------------------------------------
803376 14-SEP-05 10.54.39.860 AM control file parallel write
803187 14-SEP-05 10.51.30.646 AM control file sequential read
803170 14-SEP-05 10.51.13.626 AM db file parallel write
803165 14-SEP-05 10.51.08.626 AM control file parallel write
803162 14-SEP-05 10.51.05.626 AM control file parallel write
802948 14-SEP-05 10.47.31.399 AM control file parallel write
802728 14-SEP-05 10.43.51.163 AM control file parallel write
802511 14-SEP-05 10.40.13.934 AM control file parallel write
802474 14-SEP-05 10.39.36.894 AM db file sequential read
802473 14-SEP-05 10.39.35.894 AM db file sequential read
802294 14-SEP-05 10.36.36.699 AM control file parallel write
802077 14-SEP-05 10.32.59.483 AM control file parallel write
801869 14-SEP-05 10.29.31.267 AM control file parallel write
801652 14-SEP-05 10.25.54.043 AM control file parallel write
801435 14-SEP-05 10.22.16.810 AM control file parallel write
801218 14-SEP-05 10.18.39.596 AM control file parallel write
801149 14-SEP-05 10.17.30.526 AM control file sequential read
801004 14-SEP-05 10.15.05.372 AM control file parallel write
800787 14-SEP-05 10.11.28.168 AM control file parallel write
19 rows selected.
|
我们可以看到通过ASH，Oracle以更低粒度记录了活动session所产生的等待以及等待事件。
通过这些信息我们不仅可以分时段的观察数据库系统，甚至可以划出每个等待时间的趋势图来。这对于我们了解系统运行状况，对数据库进行实时或历史状态跟踪提供了巨大的帮助。
我们可以通过OEM来生成report,也可以通过Oracle新提供的一个脚本来完成这个工作，这个脚本是:
$ORACLE_HOME/rdbms/admin/ashrpt.sql |
运行此脚本以后就会生成这样一个报告:
SQL> @$ORACLE_HOME/rdbms/admin/ashrpt.sql
Current Instance
~~~~~~~~~~~~~~~~
DB Id DB Name Inst Num Instance
----------- ------------ -------- ------------
3965153484 DANALY 1 danaly
Specify the Report Type
~~~~~~~~~~~~~~~~~~~~~~~
Enter 'html' for an HTML report, or 'text' for plain text
Defaults to 'html'
Enter value for report_type: text
Type Specified: text
Instances in this Workload Repository schema
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DB Id Inst Num DB Name Instance Host
------------ -------- ------------ ------------ ------------
* 3965153484 1 DANALY danaly danaly.hurrr
ay.com.cn
Defaults to current database
Using database id: 3965153484
Defaults to current instance
Using instance number: 1
ASH Samples in this Workload Repository schema
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Oldest ASH sample available: 12-Sep-05 19:36:11 [ 2342 mins in the past]
Latest ASH sample available: 12-Sep-06 19:33:24 [ ###### mins in the past]
Specify the timeframe to generate the ASH report
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Enter begin time for report:
-- Valid input formats:
-- To specify absolute begin time:
-- [MM/DD[/YY]] HH24:MI[:SS]
-- Examples: 02/23/03 14:30:15
-- 02/23 14:30:15
-- 14:30:15
-- 14:30
-- To specify relative begin time: (start with '-' sign)
-- -[HH24:]MI
-- Examples: -1:15 (SYSDATE - 1 Hr 15 Mins)
-- -25 (SYSDATE - 25 Mins)
Defaults to -15 mins
Enter value for begin_time: -25
Report begin time specified: -25
Enter duration in minutes starting from begin time:
Defaults to SYSDATE - begin_time
Press Enter to analyze till current time
Enter value for duration:
Report duration specified:
Using 14-Sep-05 10:13:59 as report begin time
Using 14-Sep-05 10:39:26 as report end time
Specify Slot Width (using ashrpti.sql) for 'Activity Over Time' section
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- Explanation:
-- In the 'Activity Over Time' section of the ASH report,
-- the analysis period is divided into smaller slots
-- and top wait events are reported in each of those slots.
-- Default:
-- The analysis period will be automatically split upto 10 slots
-- complying to a minimum slot width of
-- 1 minute, if the source is V$ACTIVE_SESSION_HISTORY or
-- 5 minutes, if the source is DBA_HIST_ACTIVE_SESS_HISTORY.
Specify Slot Width in seconds to use in the 'Activity Over Time' section:
Defaults to a value as explained above:
Slot Width specified:
Specify Report Targets (using ashrpti.sql) to generate the ASH report
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- Explanation:
-- ASH Report can accept "Report Targets",
-- like a particular SQL statement, or a particular SESSION,
-- to generate the report on. If one or more report targets are
-- specified, then the data used to generate the report will only be
-- the ASH samples that pertain to ALL the specified report targets.
-- Default:
-- If none of the report targets are specified,
-- then the target defaults to all activity in the database instance.
Specify SESSION_ID (eg: from V$SESSION.SID) report target:
Defaults to NULL:
SESSION report target specified:
Specify SQL_ID (eg: from V$SQL.SQL_ID) report target:
Defaults to NULL: (% and _ wildcards allowed)
SQL report target specified:
Specify WATI_CLASS name (eg: from V$EVENT_NAME.WAIT_CLASS) report target:
[Enter 'CPU' to investigate CPU usage]
Defaults to NULL: (% and _ wildcards allowed)
WAIT_CLASS report target specified:
Specify SERVICE_HASH (eg: from V$ACTIVE_SERVICES.NAME_HASH) report target:
Defaults to NULL:
SERVICE report target specified:
Specify MODULE name (eg: from V$SESSION.MODULE) report target:
Defaults to NULL: (% and _ wildcards allowed)
MODULE report target specified:
Specify ACTION name (eg: from V$SESSION.ACTION) report target:
Defaults to NULL: (% and _ wildcards allowed)
ACTION report target specified:
Specify CLIENT_ID (eg: from V$SESSION.CLIENT_IDENTIFIER) report target:
Defaults to NULL: (% and _ wildcards allowed)
CLIENT_ID report target specified:
Specify the Report Name
~~~~~~~~~~~~~~~~~~~~~~~
The default report file name is ashrpt_1_0914_1039.txt. To use this name,
press |
当然怎样分析和使用这个report仍然要靠对数据库的深入了解才行。
历史上的今天...
>> 2015-09-14文章:
>> 2011-09-14文章:
>> 2009-09-14文章:
>> 2008-09-14文章:
>> 2006-09-14文章:
>> 2004-09-14文章:
By eygle on 2005-09-14 11:18 | Comments (2) | Oracle12c/11g | 432 |
勤奋的eygle啊
下周我回北京，该给我接风洗尘啦
你丫的生活过的滋润的很!