i was wondering
im getting different results when using geography() on different positions within a query.
So, whats the most accurate way of forcing geography() over a functions with geometry columns?
example:
SELECT
polys.id,
sum(st_length(st_intersection(geography(lines.the_geom),geography polys.the_geom))))/1000 total_lengths
from schema.table1polys polys schema.table2lines lines on ST_Intersects(geography(lines.the_geom),geography(polys.the_geom))
..or..
SELECT
polys.id,
sum(st_length(geography(st_intersection(lines.the_geom,polys.the_geom))))/1000 total_lengths
from schema.table1polys polys schema.table2lines lines on ST_Intersects(geography(lines.the_geom),geography(polys.the_geom))
whats the most accurate? i have sort of 2 / 3 Km of difference between both querys.