-- Divide an input geometry into equal-length portions of the specified length.
-- The final segment will contain the "unused" portion of the line and will be
-- shorter than the others.
CREATE OR REPLACE FUNCTION pg_temp.DivideLine(g geometry, segment_length double precision)
RETURNS SETOF geometry AS $$
    SELECT ST_LineSubstring($1,
                            i*$2/length_m,
                            LEAST(1.0, (i+1)*$2/length_m))
    FROM (SELECT $1, ST_Length($1) AS length_m) sq
    CROSS JOIN LATERAL generate_series(0, floor(length_m / $2)::int) AS i
$$ LANGUAGE SQL;