The ST_TransformGeom method transforms a single geometry given the transform definition of
the destination. The transformation is performed using the PROJ.4 library.
This method can be used in select situations when the appropriate spatial reference
systems have not yet been created in the database. If the appropriate spatial reference
systems are available, the ST_Transform method is often more appropriate.
Transformations from a lat/long system to a Cartesian system can be problematic for polar points. If the database server is
unable to transform a point close to the North or South pole, the latitude value of the point is shifted a small distance
(slightly more than 1e-10 radians) away from the pole, and along the same longitude, so that the transformation can succeed.