How can I avoid a full table scan on this mysql query?

Question

explain
select
    *
from
    zipcode_distances z 
inner join
    venues v    
    on z.zipcode_to=v.zipcode
inner join
    events e
    on v.id=e.venue_id
where
    z.z         


        

Answer 1

Have indexed the columns in both tables?

e.id and v.venue_id

If you do not, creates indexes in both tables. If you already have, it could be that you have few records in one or more tables and analyzer detects that it is more efficient to perform a full scan rather than an indexed read.