[postgis-users] Re: [mapserver-users] MapServer Performance

[Paul Ramsey]

Here's a smattering of postings which give the flavour:

http://postgis.refractions.net/pipermail/postgis-users/2002-September/001472.html
http://mapserver.gis.umn.edu/wilma/mapserver-users/0110/msg00283.html
http://postgis.refractions.net/pipermail/postgis-users/2002-August/001385.html

Incidentally, Dave committed the mappostgis.c changes back into the 3.6 
tree as well last week, so a checkout of the 3.6 CVS branch will get you 
the latest and greatest also.

P.

Vinko Vrsalovic wrote:
> On Thu, Nov 21, 2002 at 09:02:40PM -0800, Paul Ramsey wrote:
>  
> 
>>Check out some of Jan's postings in the past regarding doing 
>>classification on the fly from PostGIS. One of the keys to good 
>>performance is pushing the calculations back into the database. So 
>>rather than adding X classes with expressions in them, do the 
>>classification in the db with a CASE expression and simplify the class 
>>expressions down the a CLASSITEM and a simple match (EXPRESSION "blah").
> 
>  
> Ok, I'll look at that, but I can't find Jan's postings about
> classification on the fly, could you please point me to the month,
> subject or URL for those articles?
>  
> 
>>Also I do not entirely understand what is going on in steps 1 and 2. You 
>>are adding to the db for every query?
> 
> 
> For every access that needs to classify the data (there are some which
> don't need that). The problem is that the data comes from another DB
> (Oracle) in another machine (a Sun machine) in another application
> (independent from the one I'm implementing). So I need to retrieve the
> data from that application, and then classify the features according to it.
> 
> 
>>Finally, you do not need views necessarily since you can now form a DATA 
>>statement out of arbitrary SQL. I am afraid we still do not have a 
>>comprehensive guide on this topic yet... sorry.
> 
> 
> In the CVS for MS 3.7? PostGIS 0.7.3?
> 
> I'm now running on PostGIS 0.7.3 with MS 3.6...
> 
> Is there a simple example at least?
> 
> Thanks!,