alexreisner/geocoder — pull request #573 by phallstrom (2013-12-24 01:15:51+00:00)
Title: Functionality to pass optional :min_radius value to 'near' searches.

Only works with ActiveRecord and not Sqlite. Default's to zero. I checked the documentation for MySQL, PostgreSQL, and Oracle. All three state that "A BETWEEN B AND C" is equivalent to "A >= B AND A <= C" so there shouldn't be any performance impact constraining all queries to use a minimum radius of zero.