Tag Archives: gis

[oracle] avoiding SLOW sdo_aggr_union

There is this recurring problem we have in GIS: getting road-segments and wanting to show complete roads. The naive approach would we to do something like the following: insert into street_geoms select ro.rd_ro_ident, ro.rd_ro_name, ro.com_code, ssdo_aggr_union(sdoaggrtype(rd.ro_geometry, 0.005)) as geom from rd_road ro, rd_ro_sec ros where ros.rd_ro_ident = ro.rd_ro_ident group by ro.rd_ro_ident, ro.rd_ro_name, ro.com_code; For good […]

Spatial DB Advisor

PL/SQL package: lessons learned Working with Oracle Spatial a lot, I found a great source of information in the Spatial DB Advisor, which besides a lot of interesting articles, also offers his source-code and PL/SQL packages for free. The site is not very user-friendly (trouble of seeing the threes through the wood), as finding the […]