On 2 September 2013 18:10, Alexander Ulanov <[email protected]> wrote: > Does this mean that all bounding box queries have to be written with casting > to geometry type? Bounding box originates from the browser with google maps.
I suppose so, as long as the map used to base the BBOX queries share the same grid orientation as a lat/long grid (not the case for UTM, LCC and others, but true for Mercator projections). To get a good idea of a straight line for the geography type you have to see it on a globe (or something like Google Earth), but never on a flat map. > Related question. Do I really need geography type for my locations if my > queries are only bounding box and st_dwithin ? Geography types are still really handy for ST_DWithin, since they use nice linear metric units for distances. So I guess it depends how much you use this function or other distance-based functions. There are also several ways to get metric area and distance values from geometry data of long/lat too. Be sure to read the relevant manual section [1] to help you decide. [1] http://postgis.net/docs/using_postgis_dbmanagement.html#PostGIS_Geography -Mike _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
