I would suggest to do everything with SQL views and pl/pgSQL functions. From what I read, ORM seems to add an unnecessary, inefficient layer unless you want to get involved in complex OO design and develop a portable solution (http://en.wikipedia.org/wiki/Object-relational_mapping).
My two cents. Pierre >-----Original Message----- >From: [email protected] [mailto:postgis-users- >[email protected]] On Behalf Of William Furnass >Sent: 30 juillet 2010 08:40 >To: PostGIS Users Discussion >Subject: [postgis-users] Strategies for rapid application development using >PostGIS > >I wish to use PostGIS/PostgreSQL for data mining exercise (MSc >project) rather than developing fully-fledged GIS app, the goal being >to determine the causes of water quality issues in a water >distribution network. I need to: > - filter and pre-process several datasets (each containing ~10^5 >records) describing water quality issue events and possible cause >events > - associate the events in different cause and effect datasets with >edges/nodes in my distribution network model to produce an 'integrated >network model' > - traverse the network model, giving consideration to the network >hydraulics, in an attempt to associate one or more possible causes >with each water quality issue. > >I believe I can achieve most of this using 'standard' SQL, PostGIS >functions and possibly some recursive PL/pgSQL functions to traverse >my network structures and then visually verify that the region of >influence determined for each water quality event is sane using >Quantum GIS. However, I would very much like to automate aspects of >the dataset processing, integrated model construction and model >analysis to allow me to more easily perform sensitivity analysis on >certain parameters, to reduce the amount of ugly adhoc snippets of >(say) Python that I need to write and to perhaps allow the analysis >parameters to be set and the results viewed from a QGIS plugin. > >I've considered baking lots of SQL into pyodbc cursor.execute(sql) >calls but think that such an approach could get rather messy. I've >also taken a look at the SQLAlchemy/GeoAlchemy ORM framework, which >initially seems to be rather too heavy for my needs and would require >me to spend much time finding ways to rewrite complex queries >involving many joins and much nesting. I should also mention that I >have little time to devise an analysis tool and generate some results >and that I haven't done much programming (OOP or otherwise) for a >number of years. > >How do other list subscribers manage data analysis projects (as >opposed to full-on GIS application development projects) using >PostGIS? How far into writing ORM code or integrating an existing ORM >framework have people gone when undertaking similar tasks? >_______________________________________________ >postgis-users mailing list >[email protected] >http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
