v$active_session_history 视图无数据

发布时间 2023-04-04 15:28:08作者: www.cqdba.cn

适用范围

ORACLE 所有版本

问题概述

海外客户ORACLE 19.11 出现了跑批性能问题,需要协助分析,但是在分析过程中,AWR,ASH均无数据。 v$active_session_history 视图也数据。

SQL> select count(*) from v$active_session_history ;

  COUNT(*)
----------
         0

问题原因

通过分析可能是未购买ORACLE诊断包的许可,未开启相关功能。

#查看数据库版本
SQL> select *  from v$version ;

BANNER
--------------------------------------------------------------------------------
BANNER_FULL
----------------------------------------------------------------------------------------------------------------------------------------------------------------
BANNER_LEGACY                                                                        CON_ID
-------------------------------------------------------------------------------- ----------
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.11.0.0.0
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production                    0

#查看是否开启了ash功能
SQL>  SELECT a.ksppinm "parameter",b.ksppstvl "session value",c.ksppstvl "instance value",a.KSPPDESC  FROM x$ksppi a, x$ksppcv b, x$ksppsv c WHERE a.indx = b.indx AND a.indx = c.indx AND a.ksppinm LIKE '%_ash_enable%'

parameter                           session value   instance value  KSPPDESC
----------------------------------- --------------- --------------- --------------------------------------------------
_right_outer_hash_enable            TRUE            TRUE            Right Outer/Semi/Anti Hash Enabled
_ash_enable                         TRUE            TRUE            To enable or disable Active Session sampling and f
                                                                    lushing
#查看被禁用的option选件 
SQL> select * from v$option where value='FALSE';

PARAMETER                           VALUE                                                                CON_ID
----------------------------------- ---------------------------------------------------------------- ----------
Partitioning                        FALSE                                                                     0
Real Application Clusters           FALSE                                                                     0
Automatic Storage Management        FALSE                                                                     0
Oracle Label Security               FALSE                                                                     0
OLAP                                FALSE                                                                     0
Advanced Analytics                  FALSE                                                                     0
Oracle Database Vault               FALSE                                                                     0
Real Application Testing            FALSE                                                                     0
Unified Auditing                    FALSE                                                                     0
Management Database                 FALSE                                                                     0
I/O Server                          FALSE                                                                     0
ASM Proxy Instance                  FALSE                                                                     0
Data Mining                         FALSE                                                                     0

13 rows selected.

#查看是否使用过 Tuning 包
SQL> @options_packs_usage_statistics.sql
OVERALL INFORMATION

HOST_NAME                               |INSTANCE_NAME   |DATABASE_NAME |OPEN_MODE       |DATABASE_ROLE   |CREATED            |      DBID|VERSION    |BANNER
----------------------------------------|----------------|--------------|----------------|----------------|-------------------|----------|-----------|--------------------------------------------------------------------------------
hgcoracledb                             |orcl12c         |ORCL12C       |READ WRITE      |PRIMARY         |2022.05.12_14.01.37| 934992385|12.1.0.2.0 |Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production

PARAMETER                     |VALUE
------------------------------|--------------------
control_management_pack_access|NONE
enable_ddl_logging            |FALSE

 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
PRODUCT USAGE
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

PRODUCT                                            |USAGE                   |LAST_SAMPLE_DATE   |FIRST_USAGE_DATE   |LAST_USAGE_DATE
---------------------------------------------------|------------------------|-------------------|-------------------|-------------------
Active Data Guard                                  |NO_USAGE                |2023.03.30_11.54.46|                   |
Advanced Analytics                                 |NO_USAGE                |2023.03.30_11.54.46|                   |
Advanced Compression                               |NO_USAGE                |2023.03.30_11.54.46|                   |
Advanced Security                                  |NO_USAGE                |2023.03.30_11.54.46|                   |
Database In-Memory                                 |NO_USAGE                |2023.03.30_11.54.46|                   |
Database Vault                                     |NO_USAGE                |2023.03.30_11.54.46|                   |
Diagnostics Pack                                   |NO_USAGE                |2023.03.30_11.54.46|                   |
Label Security                                     |NO_USAGE                |2023.03.30_11.54.46|                   |
OLAP                                               |NO_USAGE                |2023.03.30_11.54.46|                   |
Partitioning                                       |NO_USAGE                |2023.03.30_11.54.46|                   |
RAC or RAC One Node                                |NO_USAGE                |2023.03.30_11.54.46|                   |
Real Application Clusters                          |NO_USAGE                |2023.03.30_11.54.46|                   |
Real Application Clusters One Node                 |NO_USAGE                |2023.03.30_11.54.46|                   |
Real Application Testing                           |NO_USAGE                |2023.03.30_11.54.46|                   |
Spatial and Graph                                  |NO_USAGE                |2023.03.30_11.54.46|                   |
Tuning Pack                                        |NO_USAGE                |2023.03.30_11.54.46|                   |
.Database Gateway                                  |NO_USAGE                |2023.03.30_11.54.46|                   |
.Exadata                                           |NO_USAGE                |2023.03.30_11.54.46|                   |
.GoldenGate                                        |NO_USAGE                |2023.03.30_11.54.46|                   |
.HW                                                |NO_USAGE                |2023.03.30_11.54.46|                   |
.Pillar Storage                                    |NO_USAGE                |2023.03.30_11.54.46|                   |


#查看 control_management_pack_access
SQL> show parameter control_management_pack_access ;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
control_management_pack_access       string      NONE

control_management_pack_access 值为NONE会禁用 DIAGNOSTIC+TUNING。其中:

. 该DIAGNOSTIC包包括 AWR、ADDM 等。

. 该TUNING包包括 SQL Tuning Advisor、SQLAccess Advisor 等。

DIAGNOSTIC启用需要TUNING的许可证。

解决方案

1.向客户确认是否有有TUNING的 license
2.修改 control_management_pack_access 参数

#修改参数 
alter system set control_management_pack_access='DIAGNOSTIC+TUNING' scope=both ; 

#重启ASH
alter system set "_ash_enable"=false ;
alter system set "_ash_enable"=true  ;

#调整_ash_size大小建议在1G以内
alter ssytem set "_ash_size"=275M; 

参考文档

https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/CONTROL_MANAGEMENT_PACK_ACCESS.html#GUID-A5CA11BA-AE1F-4A2E-9C59-A98BA1F4E5C2