On Fri, Mar 17, 2006 at 11:41:11PM -0500, Tom Lane wrote:
> Dan Harris <fbsd@drivefaster.net> writes:
> > Furthermore, by doing so, I am tying my queries directly to
> > "postgres-isms". One of the long term goals of this project is to be
> > able to fairly transparently support any ANSI SQL-compliant back end
> > with the same code base.
>
> Unfortunately, there isn't any portable or standard (not exactly the
> same thing ;-)) SQL functionality for dealing gracefully with
> two-dimensional searches, which is what your lat/long queries are.
The OpenGIS Simple Features Specification[1] is a step in that
direction, no? PostGIS[2], MySQL[3], and Oracle Spatial[4] implement
to varying degrees. With PostGIS you do have to add non-standard
operators to a query's predicate to benefit from GiST indexes on
spatial columns, but the rest of the query can be straight out of
the SQL and OGC standards.
[1] http://www.opengeospatial.org/docs/99-049.pdf
[2] http://www.postgis.org/
[3] http://dev.mysql.com/doc/refman/5.0/en/spatial-extensions.html
[4] http://www.oracle.com/technology/products/spatial/index.html
--
Michael Fuhr
