Changes between Version 14 and Version 15 of BluePrintGISStorage

Timestamp:

02/07/12 09:48:18 (13 years ago)

Author:

Fran Boon

Comment:

--

BluePrintGISStorage

@@ +1 @@
+= GIS Storage =
 [[TOC]]
-= GIS Storage =
-For portability, the default storage for Features is the normal database via Web2Py's [http://mdp.cti.depaul.edu/examples/default/orm DAL].
+For portability, the default storage for Features is the normal database via Web2Py's [http://web2py.com/books/default/chapter/29/6 DAL].
 
 In order to support Lines & Polygons we store as [http://en.wikipedia.org/wiki/Well-known_text WKT]
@@ -10 +10 @@
 
 We can extend DAL for spatial support:
- * adding if deployment_settings.gis.spatialdb == True and deployment_settings.database.db_type == "postgres" to routines inside S3GIS' spaital functions to use optimsied routines where possible & falling back to the existing Shapely routines.
+ * adding if deployment_settings.gis.spatialdb == True and deployment_settings.database.db_type == "postgres" to routines inside S3GIS' spaital functions to use optimised routines where possible & falling back to the existing Shapely routines.
 
 We could [http://groups.google.com/group/web2py/browse_thread/thread/7551b50ef3ca72a8 bypass DAL completely] & use an ORM like [http://geoalchemy.org/ GeoAlchemy]:
 {{{
-response.custom_commit=lambda: do_commit()
+response.custom_commit = lambda: do_commit()
 }}}
 
@@ -46 +46 @@
 I guess we have a PostGIS Adapter which inherits from the PostgreSQL one & a Spatialite adapter which inherits from the Sqlite one.
 
-Both should inherit the OpenGIS set of SQL syntax
-
+Both should inherit the OpenGIS set of SQL syntax:
+* http://www.opengeospatial.org/standards/sfs
 
 We need to be able to do spatial queries like this:
 * http://postgis.refractions.net/docs/ST_Overlaps.html
+
 This one is our key performance bottleneck currently as we do BBOX filters on GeoJSON feature layers like this:
-* http://bazaar.launchpad.net/~flavour/sahana-eden/trunk/view/head:/modules/s3/s3rest.py#L1773
+* https://github.com/flavour/eden/blob/master/modules/s3/s3rest.py#L4612
 Instead of this query:
 {{{
-bbox_filter = ((db.location.lon > minLon) & (db.location.lon < maxLon) & (db.location.lat > minLat) & (db.location.lat < maxLat))
+bbox_filter = ((table.lon > minLon) & (table.lon < maxLon) & (table.lat > minLat) & (table.lat < maxLat))
 }}}
 We want to:
 {{{
-bbox_filter = (db.location.ST_Overlaps([minLon, minLat, maxLon, maxLat]))
+bbox_filter = (table.ST_Overlaps([minLon, minLat, maxLon, maxLat]))
 }}}
 
@@ -66 +67 @@
 
 
-We could also want to be able to specify that a table is spatialised, so an option to db.define_table(spatial=True).
+We also want to be able to specify that a table is spatialised, so an option to db.define_table(spatial=True).
 If this is on then we should send AddGeometryColumn() to the SQL Adapter
 
@@ -75 +76 @@
 There are also some new field types, but I don't think we need to worry about those right now.
 
-Full specs are here:
-* http://www.opengeospatial.org/standards/sfs
-
 ----
 [wiki:BluePrintGeographicInformationSystems GIS BluePrints]