STI types stored in a database

I am trying to:

avoid redundancy of types in tables
link every type with additional information (eg: type descripton...)

Does anyone know if there's a way to substitute the type column with a
type_id column, that would link to a types table ?

So i guess my only solution if i want to sort by type is to create an
index on a varchar column... I am not an expert at databases, but do
you know if this would be considered bad practice?