[mapserver-users] performance question - joining dbf tables in MapServer

[Mark Volz]

Steve,

That will help.  Thank You!

Sincerely,
Mark Volz

From: Lime, Steve D (MNIT) [mailto:Steve.Lime at state.mn.us]
Sent: Friday, August 19, 2016 1:53 PM
To: Mark Volz <MarkVolz at co.lyon.mn.us>; mapserver-users at lists.osgeo.org
Subject: RE: [mapserver-users] performance question - joining dbf tables in MapServer

Joins are really meant for simple look ups so there is no indexing or anything like that with the DBF and flat file options. Also note that JOINs are post-query-only so you couldn't label based on a joined column, nor query on a joined attribute. You could keep information you wanted to display as the result of a query however.

In short, if you have a relatively small set of attributes that you want to display as a result of a query then a JOIN might work well.  Does that help?

Steve

From: mapserver-users [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of Mark Volz
Sent: Thursday, August 18, 2016 8:23 AM
To: mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>
Subject: [mapserver-users] performance question - joining dbf tables in MapServer

Hello,

I am considering joining my tax data to my parcel dataset on the fly using the MapServer Join function.  This way I can update my tax data weekly, and my parcels as needed.  My tax data will be in a dbf and my parcels will be in a shapefile.

Questions:

*         Is there any performance hit using joining on the fly vs keeping the tax data in the shapefile?

*         Are there any tips I should be aware about to make the joins work faster?

http://mapserver.org/mapfile/join.html.


Thank You!


Sincerely,
Mark Volz
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