What is the unit in returned by MySQL GLength method?

Question

I want to get the length in meters between 2 points in the surface of the Earth. But the GLength method returns an unexpected value

http://dev.mysql.com/doc/refman/5.0/en/geometry-property-functions.html#function_glength

SELECT GLength(GeomFromText(
   'LINESTRING(-67.8246 -10.0073,-67.8236 -10.0082)', 4326))

actual result

0.00134536240471071

expected value in meters:

147

Answer 1

I haven't found a source, but I was playing with this method and I concluded that the result is given in the same unit used in the WKT.

And the distance is calculated in planar coordinates. The SRID is not taken into account.