RE: No hood in a pizza shop?
If you are looking to vent hot air, that is one thing. But if you are talking about a full blown commercial exhaust hood with a fire suppression system as usually seen over a stove, then in some states they are not required, as pizza ovens, or all ovens, are considered a closed, contained, unit and do not generate what are called "grease laden vapors". (even a conveyer oven that IS open on both ends...)
(Retired Fire Prevention Inspector)