what is oracle's minimum username length?

I know 3 lengths are supported for example "SAA" but "SA" or "S" is possible? My Oracle versions are 11.2.0.4, 11.2.0.1, 12.1 and 12.2. What is the minimum username length on these versions?

Solution

There is no restriction on the minimum length of the username in any oracle version.

SQL> create user a identified by oracle;

User created.

SQL>

It is mentioned in the oracle documents that,

Specify the name of the user to be created. This name can contain only characters from your database character set and must follow the rules described in the section "Schema Object Naming Rules". Oracle recommends that the user name contain at least one single-byte character regardless of whether the database character set also contains multibyte characters.

Also refer this: Database Object Naming Rules