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Asked: 2026-05-10T16:25:37+00:00

I’m using a lat/long SRID in my PostGIS database (-4326). I would like to

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I’m using a lat/long SRID in my PostGIS database (-4326). I would like to find the nearest points to a given point in an efficient manner. I tried doing an

ORDER BY    ST_Distance(point, ST_GeomFromText(?,-4326))

which gives me ok results in the lower 48 states, but up in Alaska it gives me garbage. Is there a way to do real distance calculations in PostGIS, or am I going to have to give a reasonable sized buffer and then calculate the great circle distances and sort the results in the code afterwards?

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1 Answer

  1. You are looking for ST_distance_sphere(point,point) or st_distance_spheroid(point,point).

    See:

    http://postgis.refractions.net/documentation/manual-1.3/ch06.html#distance_sphere http://postgis.refractions.net/documentation/manual-1.3/ch06.html#distance_spheroid

    This is normally referred to a geodesic or geodetic distance… while the two terms have slightly different meanings, they tend to be used interchangably.

    Alternatively, you can project the data and use the standard st_distance function… this is only practical over short distances (using UTM or state plane) or if all distances are relative to a one or two points (equidistant projections).

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