Re: Storing co-ordinate / spatial information in non-GIS systems
- From: Jason Heinrich <jheinrich@xxxxxxxx>
- To: <Grant.Allen@xxxxxxxxxxxxxxxx>, oracle-l <oracle-l@xxxxxxxxxxxxx>
- Date: Mon, 15 Aug 2005 08:59:57 -0500
> Other dbs have implemented coordinate datatypes (PostgreSQL for instance) -
> someone might have done a port and had a bright idea.
Oracle has a geometric datatype (MDSYS.SDO_GEOMETRY), and a bunch of
functions for working with geometric data, included in the Locator component
of their Intermedia option (which is included free with both Standard and
Enterprise editions). This is a subset of the full-blown Spatial option,
which provides advanced functionality useful for GIS systems.
Coordinate, or point, data such as latitude/longitude is some of the
simplest to work with. Oracle even provides a truckload of coordinate
systems to use when doing distance calculations and such, so you don't have
to deal with such sticky things like account for the curvature of the earth
(which isn't spherical) yourself.
Unfortunately, the syntax for manipulating this data isn't completely
straightforward. I recommend reviewing the Spatial User's Guide and
Reference for more information on that.
> I'd like to store information like co-ordinate pairs (lat,
> long), a zoom level, etc. for interfacing with services like Google Earth,
> Google Maps, etc.
Having said all that, SDO_GEOMETRY won't help you very much when interfacing
with outside web services. Even if you do use SDO_GEOMETRY, I still
recommend storing the latitude and longitude separately in a more readable
format such as NUMBER. Others have already made comments on keeping that
data atomic: my vote is a check constraint like David outlined.
---------------
Jason Heinrich
Oracle Database Administrator
Pensacola Christian College
(850) 478-8496 x2509
jheinrich@xxxxxxxx
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