You can also try using the Mapserver direct Oracle connection rather than going through OGR.
LAYER NAME "aree_stradali" STATUS DEFAULT TYPE POLYGON # Dati da connessione Oracle CONNECTIONTYPE ORACLESPATIAL CONNECTION "username/sec...@localhost/sitfi02t" DATA "SPATIAL_COLUMN FROM REPLICA_TOPONOMASTICA.AGGR_AREESTRADA USING UNIQUE OBJECTID" # Dati da shapefile #DATA "shape/toponomastica/aree_strada.shp" PROJECTION "init=epsg:3003" END DUMP TRUE METADATA "wfs_title" "aree_stradali" "gml_featureid" "objectid" END CLASS STYLE COLOR 255 0 0 WIDTH 1 END END END On 6/29/09 10:51 AM, "Frank Warmerdam" <warmer...@pobox.com> wrote: > Niccolo Rigacci wrote: >> I experienced a severe performance problem with MapServer >> configured as WFS server, taking data from Oracle via GDAL/OCI >> driver. >> >> All the features take about 9.6 Mb of xml data (via WFS) or 8.4 >> Mb of text data (via ogrinfo). >> >> Retrieving all the features via WFS from a shapefile takes less >> than one second, retrieving the same WFS from Oracle takes about >> 470 seconds. Retrieving data via the ogrinfo utility takes about >> 3 seconds: >> >> Tests are performed from the same Linux box, taking data in this >> way: >> >> 1 s: wget <- http <- Remote_host <- MapServer <- GDAL <- shapefile >> 470 s: wget <- http <- Remote_host <- MapServer <- GDAL/OCI <- localhost <- >> Oracle >> 3 s: ogrinfo <- GDAL/OCI <- Remote_host <- Oracle >> >> It seems that wget (int the Oracle case) starts at about 400 >> Kb/sec transfer rate, then it drops down to 13 Kb/sec a few >> seconds later. >> >> Does somebody have any idea where is the bottleneck? How can I >> debug such slodown? > > Niccolo, > > This is almost certainly due to the two-pass query approach in mapserver. > On the first pass the id's of all features matching the query are collected > and then the features are fetched, one by one, by id. In the case of the > oci driver in OGR a fetch by id issues an sql select statement. So you are > basically getting one sql select statement per features which is very > inefficient. > > What you need if you want to do large amounts of feature query - such as for > WFS - is the new one pass query mechanism that Steve is working on. I'm not > exactly clear on it's status. > > Note that this two pass query anti-optimization does not affect feature > drawing which is accomplished in one pass. It also does not significantly > affect formats like shape where fetching by id's has no noticable overhead. > > Best regards, _______________________________________________ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users