To answer this question, we need to understand the different parameters that can be defined when creating a new user in a database.
Option A) default tablespace - This option is defined at user creation. The default tablespace specifies the tablespace where the user's objects will be created by default.
Option B) profile - This option is defined at user creation. A profile is a set of parameters that define the resource limits and password management rules for a user.
Option C) idle_time - This option is NOT defined at user creation. The idle_time parameter is used to specify the maximum number of minutes of inactivity allowed before the user's session is terminated. This parameter is typically set after user creation to define session timeout rules.
Option D) default role - This option is defined at user creation. The default role specifies the roles that are automatically enabled for the user when they log in.
The correct answer is C) idle_time. This option is not defined at user creation.