irstv/H2GIS — pull request #228 by agouge (2014-03-24 17:24:23+00:00)
Title: Prevent calculation from being done 3 times

H2 calls this function 3 times, sometimes just to get the column names.
This is a hack to prevent the calculation from being done 3 times. It is
done only when necessary. See
https://groups.google.com/forum/#!topic/h2-database/NHH0rDeU258