How can a duty police weapon only have a two inch barrel?

I don't know about the others, but Portugal is the 14th most secure country in the world. There are no need of powerful guns. There are policeman's that had never shot a gun in their lives. There are even policeman's that never had a gun, and i would dare to say, that there are 90% of the police that don't use their guns in an official way for several years, even decades.