simple name

The rules for a simple name are:

1 to 30 bytes.
Not an Oracle reserved word.
Unique within the namespace.
Not case-sensitive; any lower-case letters are converted to uppercase.
No quotation marks.
Begins with an alphabetic character from the database character set.
Contains only alphanumeric characters from the database character set and the underscore (_), dollar sign ($), and pound sign (#). However, Oracle strongly discourages you from using the dollar or pound sign. If your database character set contains multi-byte characters, Oracle recommends that you include at least one single-byte character in each logical name.

The following namespaces control the uniqueness of object names:

Schema. The names of cubes and dimensions must be unique within a schema. They cannot conflict with the names of tables, views, indexes, relational dimensions, or any other first class objects.
Cube. The names of measures must be unique within a cube.
Dimension. The names of hierarchies, levels, and attributes must be unique within a dimension and among themselves. For example, a dimension cannot have a hierarchy named Total and a level named Total.