Oracle timed_statistics parameter description

 

Description of timed_statistics parameters on MOS:

Init. ora parameter "timed_statistics" reference note [ID 30824.1]

Health checkalert: Consider setting timed_statistics and statistics_level to recommendedlevels [ID 957433.1]

 

 

Version	Parameter		Type	Modifiable
11.1.0.7	Timed_statistics	Boolean	Alter session Alter System (immediate)
11.1.0.6	Timed_statistics	Boolean	Alter session Alter System (immediate)
10.2.0.4	Timed_statistics	Boolean	Alter session Alter System (immediate)
10.2.0.3	Timed_statistics	Boolean	Alter session Alter System (immediate)
10.1.0.5	Timed_statistics	Boolean	Alter session Alter System (immediate)
10.1.0.4	Timed_statistics	Boolean	Alter session Alter System (immediate)
9.2.0.8	Timed_statistics	Boolean	Alter session Alter System (immediate)
9.0.1.4	Timed_statistics	Boolean	Alter session Alter System (immediate)
8.1.7.4	Timed_statistics	Boolean	Alter session Alter System (immediate)

 

Timed_statisticsspecifies whether or not statistics related to time are collected. it isimportant to set timed_statistics = true for obtaining timing information whichwill help in tuning the database.

-- Timed_statistics: Specifies whether to collect time-related statistics. When it is set to true, more information about the time is obtained to help optimize the database.

 

You can set this parameter in the following three ways:

(1) initialization parameters

The parameter can be set in theinitialisation file e.g.

Timed_statistics = true

 

(2) system level:

This parameter can be set at system levele. G.

Alter system settimed_statistics = true

 

(3) Session level:

This parameter can be set at session levele. G.

Alter session set timed_statistics = true

 

 

When timed_statistics is enabled statistics are generated for the following:

(1) Parse, exec and fetch CPU costs intrace files

(2) V $ waitstat

(3) V $ filestat and V $ tempstat

(4) V $ sysstat and V $ sesstat timedstatistics

 

Statistics affected by enabling timed_statistics include

CPU used when call started CPU used by this session Parse time CPU Parse time elapsed Redo write time Session connect time

 

Wait Times arerecorded in V $ session_event, V $ system_event and V $ session_wait irrespective ofthe setting of timed_statistics (9.2.0)

 

For the default value of this parameter, the timed_statistics parameter is described on the official website:

Http://docs.oracle.com/cd/E11882_01/server.112/e25513/initparams255.htm#REFRN10218

 

If statistics_level is set to typical or all, then true

If statistics_level is set to basic, then false

 

If statistics_level is set to typical or all, timed_statistics is set to true by default. If statistics_level is set to basic, timed_statistics defaults to false.

 

Description of statistics_level on MOS:

Statistics_levelspecifies the level of collection for the database and operating systemstatistics. the Oracle database collects these statistics for a variety ofreasons, including making self-management decisions. setting thestatistics_level parameter to basic disables the collection of parameter importantstatistics required by Oracle database features and functionality. statistics_level = All shoshould only be set for diagnostic purposes as required.

 

This parameter is described in the previous blog:

Summary of Oracle statistic statistics

Http://blog.csdn.net/tianlesoftware/article/details/4668723

 

 

 

 

 

 

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------- Add a group to describe the relationship between Oracle tablespace and data files in the remarks section. Otherwise, reject the application ----

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