TypeId describes the static information about a SQL type independent of any specific attributes of the type such as length. So the TypeId for CHARACTER describes the fundamental information about CHARACTER. A specific type (e.g. CHARACTER(10)) is described by a TypeDescriptor for a catlog type and a DataTypeDescriptor for a runtime type. (note a DataTypeDescriptor adds runtime attributes to the TypeDescriptor it has).
A TypeId is immutable.
The equals(Object) method can be used to determine if two typeIds are for the same type, which defines type id equality.
@see DataTypeDescriptor