Scope____oracle of ALTER system command parameters in Oracle

SCOPE

The SCOPE clause lets your specify when the change takes effect. Scope depends on whether your started up the database using a client-side parameter file (pfile) or server parameter file ( SPFile).

SCOPE specifies when changes to system will take effect, scope=memory|spfile|both, depending on whether the database uses Pfile or SPFile startup

MEMORY

MEMORY indicates that's is made in MEMORY, takes effect immediately, and persists until the "database is shut" . If you are started up the database using a parameter file (pfile), then this is the only scope for you can specify.

Scope=memory, which means that the modification takes effect immediately, persists until the database is shut down, and if the database is started with pfile, this is the only optional value and the default value.

SPFILE

SPFILE indicates that's the change is made in the server parameter file. The new setting takes effect the database is next shut down and started up again. Must specify SPFILE when changing the value of a static parameter this is described as not modifiable in Oracle Databa Se Reference.

Scope=spfile, the SPFile parameter is modified, and the new setting takes effect only when you reuse the SPFile to start the database.

In addition, if you modify the static parameters (can not be directly effective parameters), you must specify Scope=spfile, or if the specified memory or both will report the following error:

Ora-02095:specified initialization parameter cannot be modified

Because static parameters cannot be directly enforced by modifying the memory, you can only modify the SPFile and then restart the database to take effect.

BOTH

BOTH indicates, that's, made in memory and in the server parameter file. The new setting takes effect immediately and persists after the "database is" shut down and started up again.

Scope=both, which means that the modification takes effect immediately on memory and modifies spfile to ensure that the database is restarted.

If A server parameter file was used to start the database, then BOTH is the default. If A parameter file was used to start up the database, then MEMORY are the default, as as as the only scope can speci Fy.

If the database is started using SPFile, Scope=both is the default value

If the database is started using Pfile, Scope=memory is the default and unique value.

Static parameters, which cannot be enforced by modifying the memory (the default scope value or Scope=memory or Scope=both), and by modifying the SPFile () to restart the database.