Thanks Pavel for your answer. Do you suggest that I could use one geometry column and create several index instead?
Steve Toutant, M. Sc. Analyste en géomatique Secteur environnement Direction des risques biologiques, environnementaux et occupationnels Institut national de santé publique du Québec 945, avenue Wolfe Québec, Qc G1V 5B3 Tél.: (418) 650-5115 #5281 Fax.: (418) 654-3144 [email protected] http://www.inspq.qc.ca Pavel Iacovlev <[email protected]>@postgis.refractions.net Envoyé par : [email protected] 01/09/2009 11:34 AM Veuillez répondre à PostGIS Users Discussion <[email protected]> A PostGIS Users Discussion <[email protected]> cc Objet Re: [postgis-users] several SRID on one table The cons I think are that some 3rd party apps may get confused then working with PostGIS as they expect 1 geometry column per table, old version of QGIS have this problem (I may be wrong). In general you should have NO trouble with dual geometry columns in your app, I use this approach in production and it works fine and it's easy to implement. As a note you can create an INDEX on a geometry column that is a transformed geometry to specified projection and you should get really fast geometry on the fly projection transformation. CREATE INDEX myindex ON mytable USING GIST ( ST_Transform(the_geom, mysrid) ); Don't forget to run EXPLAINS to see if it actually works. On Tue, Sep 1, 2009 at 5:46 PM, <[email protected]> wrote: > > Hello, > We need to use a table for several purposes with different SRID. > Is it a good practice to have several geometry columns on one table or > should we create one table per SRID? > What are the pros and cons of using several geometry columns on one table? > > thanks > Steve > > Steve Toutant, M. Sc. > Analyste en géomatique > Secteur environnement > Direction des risques biologiques, environnementaux et occupationnels > Institut national de santé publique du Québec > 945, avenue Wolfe > Québec, Qc G1V 5B3 > > Tél.: (418) 650-5115 #5281 > Fax.: (418) 654-3144 > [email protected] > http://www.inspq.qc.ca > > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > -- http://iap.md, The future is open _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
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