Hi Regis, it's a long time I think to what you're descriibing, and that would definitely be on a higher level then aggregate expressions alone. This level of abstraction would also be basis for a map/reduce pattern analysis. It would be great to know some more about what has been discussed so far.
giovanni Il 23/mag/2014 22:44 "Régis Haubourg" <[email protected]> ha scritto: > Hi, > well, this is something I miss, coming from Mapinfo world. > > Some tests are being made currently on French ministry of ecology, and by > Nathan also, to head to some kind of a layer abstraction, based on ogr > virtual layer and ogr sqlite engine. > > Once done, that would open a large field of new features and dedicated > gui's: > - SQL assistant (mapinfo like / qspatialite like) on any loaded data > source > and without any explicit import step. This includes aggregate functions > - virtual attribute or spatial columns based on functions > - ETL feature for changing data types and structure > > FME is providing such kind of SQLexecutor, with some limits currently, and > that is extremly powerfull in processing tools, allowing to take full > advantage of existing algorithm for geospatial computing, and SQL-spatial > SQL for attribute queries AND processing. > > If we find a way to be sure that any datasource can be correctly used > without caveats hard to understand for the end user, I think we will have > the best GIS tool ever done for non 3D uses. Still I see some limits with > SQLITE. For instance, many SQL clauses are partially supported. Or > calculated fields in view can't be explicitly cast, so QGIS should have to > guess data type based on a data scan (a major unadressed issue of sqlite) > > I wish I had more time now to investigate by myself. > > Nathan , Hugo , could you tell us more on that topic? is ogr sqlite engine > the right target or does is have to much limitations? > > Cheers > Régis > > > > > -- > View this message in context: > http://osgeo-org.1560.x6.nabble.com/have-aggregate-window-expressions-ever-been-discussed-tp5142215p5142245.html > Sent from the Quantum GIS - Developer mailing list archive at Nabble.com. > _______________________________________________ > Qgis-developer mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-developer
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