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This article mainly introduces how to check the Oracle parameters, the article is very detailed, has a certain reference value, interested friends must read it!

There are many parameters in Oracle, and there are different ways to set them, such as:

Session level (alter SESSION set...), system level (alter SYSTEM set...), direct modification of pfile parameter files

There are three types of system-level settings:

It only works in memory (alter system set... Scope=MEMORY)-invalid after restart

Takes effect only in spfile files (alter system set...scope=SPFILE)-only after restart

Memory and spfile files take effect at the same time (alter system set. Scope=both)-default mode

The above describes how to set parameters. Let's talk about how to view the values of parameters. Viewing parameters involves the following views:

V$parameter & v$parameter2, v$system_parameter & v$system_parameter2, v$spparameter

V$parameter and V$prameter2:

The parameter value displayed in both is the value of a parameter in the current session

In addition, we usually use the most show parameter. The value corresponding to the command to view parameter values is the value in V$parameter

The only difference between the two is that when the parameter has multiple values, it is represented by a line in V$parameter, and different values are separated by commas, while different values in V$parameter2 are represented by different rows. For example, check control_files.

SQL > select name,value from v$parameter where name='control_files'

NAME

-

Control_files

VALUE

/ home/oracle/oradata/cms2009/control01.ctl, / home/oracle/oradata/cms2009/control

02.ctl, / home/oracle/oradata/cms2009/control03.ctl

SQL > select name,value from v$parameter2 where name='control_files'

NAME VALUE

Control_files / home/oracle/oradata/cms2009/control01.ctl

Control_files / home/oracle/oradata/cms2009/control02.ctl

Control_files / home/oracle/oradata/cms2009/control03.ctl

If it is a RAC environment, check out GV$parameter and GV$parameter2

V$system_parameter & v$system_parameter2:

The parameter values recorded in both are the values of the parameters in the instance, and the newly started session inherits the values of such parameters.

The difference between the two is the same as the difference between V$parameter and V$parameter2 above.

RAC environment corresponds to GV$system_parameter and GV$system_parameter2

V$spparameter:

The parameter values recorded are the values in the spfile file.

RAC environment corresponds to GV$spparameter

In addition to the above way to view the parameters, there is another special way to view: create pfile from (spfile, memory) 11g supports from memory

The new pifle generated in this way only displays the manually set parameters and parameter values, and the default parameters are not displayed, so you can more intuitively see the parameters that we have explicitly modified.

The above is all the contents of the article "how to check Oracle parameters". Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

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