Store fairway dimensions as MultiPolygon This avoids storing a single invalid geometry from the data source as multiple valid geometries with duplicate attribute sets. The previous behaviour was not correctly handled in import tracking, because only the ID of the first item in a set of multiple geometries generated from a single entry from the data source was tracked.

ALTER TABLE import.imports ADD COLUMN changed timestamp WITH time zone NOT NULL DEFAULT CURRENT_TIMESTAMP;

UPDATE import.imports imp SET
  changed = (SELECT coalesce(max(time), imp.changed)
             FROM import.import_logs
             WHERE import_id = imp.id);