PostGis vs Oracle Spatial 11g performance

Question

I am having a performance issue updating a table in Oracle Spatial 11G while converting 63,000,000 points to WKT format. I also made a comparison with Postgres. Both Postgres and Oracle run in two virtual machines hosted by the same server.

Postgres: processors 12, ram 64GB

create table alldata(geom geometry(Point, 4326));
alter table alldata add column wkt4326 varchar(100);
update alldata set wkt4326 = St_AsText(geom) -- 25 minutes

Oracle 11G: processors 12, ram 40GB, pga + sga = 8GB maximum

create table alldata(geom sdo_geometry); -- e.g.: SDO_GEOMETRY(2001, 4326, SDO_POINT_TYPE(aLon, aLat, null), null, null)
alter table alldata add (wkt4326 varchar(100));
-- **Did not complete in a hour...** 
update alldatafiltered set wkt4326 = SDO_UTIL.TO_WKTGEOMETRY(geom); 

Why is Postgres outperforming Oracle while updating tables? Which causes may affect Oracle spatial performances?

At the moment I am not leveraging any spatial index.

Answer 1

Oracle Spatial and Postgis both have their own pros and cons. While dealing with the spatial data Postgis always outperform Oracle Spatial. I have been working for last 2 year on Oracle Spatial and i recently switched to PostGIS, and i saw a huge performance difference in both of them.

The reason why it perform much faster is because spatial data parsing. In many case studies it has been derived that PostGIS is 300%-400% faster than Oracle Spatial.

PostGIS uses GEOS(Geometry Engine - Open Source) for geometry parsing while Oracle spatial has its own geometry engine which has very low parsing than GEOS.

I have found this case study to be very useful for performance comparison between PostGIS and Oracle Spatial.

In my personal opinion and experience Open source always outcomes Proprietary in Performance.