Prevent duplicate fairway areas In principal, there can be only one or no fairway area at each point on the map. Since polygons from real data will often be topologically inexact, just disallow equal geometries. This will also help to avoid importing duplicates with concurrent imports, once the history of fairway dimensions will be preserved.

DROP INDEX import.kind_idx;
CREATE INDEX import_logs_import_id ON import.import_logs (import_id);