[OSGeo-Discuss] Enterprise OSDB for OSGIS

[chenrg at lreis.ac.cn]

> warmerdam at pobox.com wrote:
> Yes, it is very important to avoid having to process too many geometries
> through GEOS if you want speedy performance.  Often some "pre screening"
> with a BBOX query can dramatically reduce the number of geometries that need
> to go through GEOS geometry tests.

The tested queries are similar to:
PostGIS:  select * from spatial_table where wkb_geometry @ 'BOX(x1 y1, x2 y2)'::box2d;
Oracle:    select * from spatial_table where SDO_FILTER(ora_geometry,  
               mdsys.sdo_geometry(2003,NULL,NULL,

               mdsys.sdo_elem_info_array(1,1003,3),

               mdsys.sdo_ordinate_array(x1,y1, x2,y2)), 'querytype=WINDOW') = 'TRUE';

ArcSDE: using VBScript

The BOX varies from 1/4 to 16 map sheet. 

As for the spatial processing, the topological data model (ArcGIS and GRASS used) performs better than the Object-relational data model (PostGIS and Oracle used). 

The newest gdal/ogr supports ArcSDE/Personal GeoGB, OCI, Imformix Spatial Blade, PostGIS/PostgreSQL and MySQL Spatial extension,  maybe we should do some tests based on gdal/ogr (SQL) API to these products.

 
> Some reasonable benchmarks would be interesting, though as Paul points out
> the specific selection of benchmarks, and the need for knowledgable tuning
> of each database makes it hard to produce meaningful benchmark results.
> I must confess to not being very knowledgable about good benchmarking
> techniques.


yes, thanks Paul. we'll be very careful about doing the best tuning of the DBMS.

  
> Is there a project page in English on the GRIDGIS project?  I've heard of
> some great work going on at your site, and would love to learn more, and to
> understand how it fits in with other ongoing developments.


not yet. The GRIDGIS is a future project (2007 - 2010). We're trying to get funds from the MOST (www.most.gov.cn) for the project. The bases for the project will be : GRASS (the new C-APIs will be completed at the end of the year), PostGIS ( as a geodatabase for GRASS?),  GDAL/OGR, Globus , OGC WS(WMS/WFS/WCS/WPS...) and so on. We'll try to build geospatial (grid) services based on these projects.



Kind regards,

Chen