Even Rouault wrote:
Re: [mapserver-users] Speeding up WFS paging with Spatialite and GeoPackage


On mardi 20 décembre 2016 13:07:27 CET Rahkonen Jukka (MML) wrote:

> https://www.postgresql.org/docs/9.1/static/sql-declare.html



In the PostGIS case (I mean not through OGR PG driver), OFFSET and LIMIT are 
also used:

https://github.com/mapserver/mapserver/blob/branch-7-0/mappostgis.c#L1968



Postgres cursors can be used when you have a persistent connection and iterate 
through the result set (that's what the OGR PG driver does in its 
GetNextFeature() implementation). But WFS is state less, so that couldn't be 
used. Or that would require special code, that could only work in fastCGI with 
defered connection closing, and likely some timeout mechanism to be able to 
ditch cursors no longer being used, to be able to reuse a Postgres iterator 
among several identical queries that would differ only by their STARTINDEX.



All right, now I understand much better this GDAL ticket 
https://trac.osgeo.org/gdal/ticket/6713 and the 2-3 times faster response time 
with tailor made system that is utilizing "next".



-Jukka-


_______________________________________________
mapserver-users mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/mapserver-users

Reply via email to