Mine are parcel databases (cadastral) for urban regions. The one for San Diego, for instance, has 800,000 rows.
Geometries are mostly polygons but some multipolygons. Will this cause a problem with the "use estimated metadata" option? If I look at the server while I'm waiting for QGIS to respond, it's usually doing a "fetch forward 200" at the time. -- John On 2010-06-09, at 7:09 PM, Chris Crook wrote: > > Hi John > > What size of database are you working with. Assuming that you have built the > indexes and analyzed the tables so that they are being used for the queries > PostgreSQL is fine for small databases. > > For larger ones (say > 10,000 records) there are some Qgis implementation > issues that can make the response very slow, at least for initially loading > the layers. These result from queries Qgis issues which result in full table > scans (for example counting the number of records, determining that all the > geometries are of the same type, determining the geographic extents of the > layer). If this is your problem you can use the pgadmin server status tool to > see these queries executing. > > With version 1.5 there is an option to "Use estimated metadata" when you are > creating the Postgres connection. This avoids some of these time consuming > queries, at the expense of not having accurate information on extents - they > are taken from the statistics generated when the table is analyzed. With > this option we are getting good response even on a national scale database of > millions of records. > > Cheers > Chris > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of John Abraham > Sent: Thursday, 10 June 2010 10:56 a.m. > To: [email protected] > Subject: [Qgis-user] Postgis speed with QGIS > > Loading and manipulating a PostGIS layer in QGIS is quite slow right now. I > have GIST indexes. I'm running both QGIS and PostGIS on the same machine. > I'm currently blaming PostgreSQL and am currently exploring configuration and > hardware options to make my PostgreSQL installation faster. > > Any suggestions on PostgreSQL configuration? Anything else I should try? > > What are others' experiences? Is there any hope for making my PostGIS layers > as fast as my shape file layers? > > -- > John Abraham > [email protected]_______________________________________________ > Qgis-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-user > ______________________________________________________________________________________________________ > > This message contains information, which is confidential and may be subject > to legal privilege. > If you are not the intended recipient, you must not peruse, use, disseminate, > distribute or copy this message. > If you have received this message in error, please notify us immediately > (Phone 0800 665 463 or [email protected]) and destroy the original message. > LINZ accepts no responsibility for changes to this email, or for any > attachments, after its transmission from LINZ. > > Thank you. > ______________________________________________________________________________________________________ > > _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
