We can set a parameter in the Oracle database to its default value. The reset process is only performed in the spfile. The parameter value in memory cannot be reset.
We can reset the value of a parameter with the following command.
SQL> alter system reset parameter_name;
SQL> alter system reset parameter_name scope=spfile;
After this process, the corresponding parameter will be completely removed from the spfile file. Even if we don’t specify a scope, the parameter will still be deleted from the spfile. There will be no changes in memory. Because the change is made in the spfile, the database needs to be restarted in order for the change to take effect.