在Oracle中，如何获取ASH报告？

jiawang

和ash相关的视图
·v$session代表数据库活动的开始，是为源起；
·v$session_wait视图用以实时记录活动session的等待情况，是当前信息；
·v$session_wait_history是对v$session_wait的简单增强，记录活动session的最近10次等待；
·v$active_session_history是ASH的核心，用以记录当前数据库活动session的历史等待信息，每秒采样1次v$session_wait，这部分内容记录在内存中，期望值是记录1个小时的内容；
·wrh$_active_session_history是v$active_session_history在AWR的存储池，v$active_session_history中记录的信息会被定期（每小时1次）地刷新到负载库中，并缺省保留一个星期用于分析；
·dba_hist_active_sess_history视图是wrh$_active_session_history视图和其他几个视图的联合展现，我们通常通过这个视图进行历史数据的访问。
为了获得最近一段时间的数据库的状态信息，我们可以生成ash报告，或查看v$active_session_history

--查看非空闲等待
select * from v$session where wait_class<>'Idle';
select * from v$session_wait where wait_class<>'Idle';

--查看ash信息
select * from v$active_session_history;

--生成ash报告
运行$ORACLE_HOME/rdbms/admin/ashrpt.sql


测试：
[oracle@strong ~]$ sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Wed Jul 19 12:41:27 2023
Version 19.3.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0

SQL> @?/rdbms/admin/ashrpt.sql

Specify the Report Type
~~~~~~~~~~~~~~~~~~~~~~~
Enter 'html' for an HTML report, or 'text' for plain text
Defaults to 'html'
Enter value for report_type:
old   2:        lower( (case when '&&report_type' IS NULL
new   2:        lower( (case when '' IS NULL
old   3:                     then '&&default_report_type'
new   3:                     then 'html'
old   4:                     when '&&report_type' <> 'text'
new   4:                     when '' <> 'text'
old   6:                     else '&&report_type' end) ) report_type
new   6:                     else '' end) ) report_type

Type Specified:  html

old   1: select '&&report_type' report_type_def from dual
new   1: select 'html' report_type_def from dual



old   1: select '&&view_loc' view_loc_def from dual
new   1: select 'AWR_PDB' view_loc_def from dual



Current Instance
~~~~~~~~~~~~~~~~

   DB Id    DB Name      Inst Num Instance
----------- ------------ -------- ------------
1575005578 ORCL                1 orcl



Instances in this Workload Repository schema
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  DB Id      Inst Num   DB Name      Instance     Host
------------ ---------- ---------    ----------   ------
* 1575005578     1      ORCL         orcl         strong




Defaults to current database

Using database id: 1575005578

Enter instance numbers. Enter 'ALL' for all instances in a
RAC cluster or explicitly specify list of instances (e.g., 1,2,3).
Defaults to current instance.

Using instance number(s): 1


ASH Samples in this Workload Repository schema
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Oldest ASH sample available:  08-May-23 17:33:41   [ ###### mins in the past]
Latest ASH sample available:  19-Jul-23 12:41:15   [      0 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: -30
Report begin time specified: -30

Enter duration in minutes starting from begin time:
Defaults to SYSDATE - begin_time
Press Enter to analyze till current time
Enter value for duration: 30


Using 19-Jul-23 12:11:42 as report begin time
Using 19-Jul-23 12:41:42 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 AWR_(PDB/ROOT)_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 WAIT_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 PLSQL_ENTRY name (eg: "SYS.DBMS_LOB.*") report target:
Defaults to NULL: (% and _ wildcards allowed)
PLSQL_ENTRY report target specified:


Specify CONTAINER name (eg: NAME from V$PDBS) report target:
Defaults to NULL: (% and _ wildcards allowed)
CONTAINER report target specified:

Specify the Report Name
~~~~~~~~~~~~~~~~~~~~~~~
The default report file name is ashrpt_1_0719_1241.html.  To use this name,
press <return> to continue, otherwise enter an alternative.
Enter value for report_name:


Specify the Report Name
~~~~~~~~~~~~~~~~~~~~~~~
The default report file name is ashrpt_1_0719_1241.html.  To use this name,
press <return> to continue, otherwise enter an alternative.
Enter value for report_name:

Using the report name ashrpt_1_0719_1241.html

Summary of All User Input
-------------------------
Format         : HTML
DB Id          : 1575005578
Inst num       : 1
Begin time     : 19-Jul-23 12:11:42
End time       : 19-Jul-23 12:41:42
Slot width     : Default
Report targets : 0
Report name    : ashrpt_1_0719_1241.html

.....
.....
.....

End of Report
</body></html>
Report written to ashrpt_1_0719_1241.html

验证
[oracle@strong ~]$ ll
total 36
-rw-r--r-- 1 oracle dba 33341 Jul 19 12:43 ashrpt_1_0719_1241.html