My team is looking into geospatial features offered by different database platforms.
Are all of the implementations database specific, or is there a ANSI SQL standard, or similar type of standard, which is being offered, or will be offered in the future?
I ask, because I would like the implemented code to be as database agnostic as possible (our project is written to be ANSI SQL standard).
Is there any known plan for standardization of this functionality in the future?
The only standard I know of is http://www.opengeospatial.org/standards/sfs and I don't know how well all the spatial database extensions implement it.
For example GIS extensions for MySQL and for PostgreSQL both follow OpenGIS "Simple Features Specification for SQL" standard.
there are a number of geo-databases which are accessible with hibernate spatial
using an abtraction layer like hibernate is a good idea anyways, if you plan to write a database agnostic application. hibernatespatial fills this gap for geo features.
I haven't tried it, but Google tells me FDO is "an open-source API for manipulating, defining and analyzing geospatial information regardless of where it is stored". It's listed on osgeo.org - a point in its favour in my opinion.
There are providers for MySQL & Oracle. Disappointingly though SQL Server and Postgis aren't listed on the FDO providers page.
Currently, there are more than one specifications followed by popular proprietary and open source implementations of spatial databases:
PostGIS, Oracle, Microsoft SQL Server and to some limited degree MySQL, all the databases implement the standard interfaces to manipulate spatial data. However, in spite of this fairly standardized features, all databases usually differ on simple SQL level what may make the database-agnostic implementation of your solution tricky. You likely need to survey the features you are interested and compare what various vendors provide.