Thank you Barend. Barend Köbben wrote: > "GIS-databases" are databases that have geometry types, so next to the > standard things such as integer, float, you can store stuff as polygon, line, > etc... Of course you could build geometry using relational tables of just > floats (for the coordinates) and some people have, but having specialised > spatial data types greatly optimises working with them, these spatial > databases then also implement "natively" spatial indices and spatial > functions (eg. "is this point inside this polygon"). > > MySQL and PostGIS both implement a standardised form of spatial data types > (by theOpenGeospatial Consortium: http://www.opengeospatial.org/ > <http://www.opengis.org> ). The main differernce is that PostGIS has tis > standard implemented almost complete, while MySQL still misses some parts. > The main missing part is the SRID or Spatial reference system support. That > means that data in MySQL will have to be in a fixed refrenece system, whereas > in PostGIS you can mix data in different ref.systems and even recalculate > data into another ref.sys. > > If you can do without that, MySQL is as good as PostGIS (and maybe better, > because it's much simpler to use and in my opinion has much better > administration tools). But if you need the missing parts, you'll use PostGIS. > > BTW, both implement the OpenGeoSpatials "Simple Feature Specification for > SQL", so you can very simply change your app to talk to either (or both) of > them... > > ____________________________ > Barend Köbben > International Institute for Geo-information Sciences and Earth Observation > (ITC) > PO Box 6, 7500AA Enschede (The Netherlands) > ph: +31-(0)534874253; fax: +31-(0)534874335 > _____________________________ > > ________________________________ > > From: [email protected] on behalf of Omar Abo-Namous > Sent: Sun 10/30/05 12:30 > To: [email protected] > Subject: Re: [svg-developers] Best GIS database? > > > > Hi, > > what exactly is sepcial about GIS-databases?? Could someone hint me to a > page with some explanations? > > thnx > > Omar > > tbone58x wrote: > >>I am guessing the open source answer is PostGIS (part of Postgres) but >>it appears that MySQL is much more popular than Postgres. Does MySQL >>support GIS like Postgres? >> >> >> >> >> >> >>----- >>To unsubscribe send a message to: [EMAIL PROTECTED] >>-or- >>visit http://groups.yahoo.com/group/svg-developers and click "edit my >>membership" >>---- >>Yahoo! Groups Links >> >> >> >> >> >> >> > > > > > > ----- > To unsubscribe send a message to: [EMAIL PROTECTED] > -or- > visit http://groups.yahoo.com/group/svg-developers and click "edit my > membership" > ---- > Yahoo! Groups Links > > > > > > > > > > > [Non-text portions of this message have been removed] > > > > > ----- > To unsubscribe send a message to: [EMAIL PROTECTED] > -or- > visit http://groups.yahoo.com/group/svg-developers and click "edit my > membership" > ---- > Yahoo! Groups Links > > > > > > > >
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