It's particularly hard on the database backends because of the overhead of running so many small queries. I should note that a true single pass query is not easy to achieve. Many presentation methods, for example WFS/GML require a result set size at the start of a file which all but requires two passes over the data. The most recent strategy involves two-passes but on the same statement handle. At the recent code sprint we tested with Oracle Spatial and PostGIS, both with significant improvements in performance. I'll probably also add a small feature cache to avoid resetting the statement handle in a majority of cases.
I'm not sure how the OGR driver will need to be updated though. The sprint modifications are implemented in the MapServer sandbox: http://svn.osgeo.org/mapserver/sandbox/single-pass/mapserver/ Steve >>> Frank Warmerdam <[email protected]> 03/31/09 8:32 PM >>> Robert Sanson wrote: > Sounds like quite an impediment. Any idea when v6.0 is likely to be > released? Robert, I would say late summer or early fall. However, I would also encourage you to try out the single-pass-query in the development version before then. I don't think this is available yet though. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [email protected] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
