[Freegis-list] user map on Postgres web site

[Brent Wood]

I guess I should apologise for the cross posting, I know this is gonna get
to lots of people more than once, but hopefully it will be of enough
interest that you'll at least read one of them :-)


There has recently been a thread on the Postgres user list about a web
based postgres user/developer map. Claire has built a Google map based
system, getting locations from IP addresses.

I suggested a fully Open Source based system might be appropriate, and
could even be a OS GIS suite showcase (applications and global raster
& vector data) if anyone wanted to take it that far.

Postgres/Postgis/mapserver seems the obvious mix, though I admit it
is not the only one. ka-map could also fit in there... as well as plenty
of other OS web-mapping related packages.

A small minority of Postgres users seem to use spatial data, and this
could present & foster a Postgres based solution for anyone interested in
adding location functionality to existing Postgres implementations.

So, is anyone out there in OS GIS world interested in becoming part of a
team to help put this together?


Brent Wood


On Wed, 26 Oct 2005, Claire McLister wrote:

> I took a look at your map, this is great wonderful that you were
> already thinking along these lines.
>
> Looks like there are two issues here: (1) Getting the data points for
> users/developers maps, and (2) using the most appropriate mapping
> technology.
>
> I think we can use the Zeemaps service (http://www.zeemaps.com) for
> number (1) above. The way this works is that you create a map and set a
> few passwords: (a) moderator, (b) member, and (c) viewer. Using the
> moderator password, you can set certain map properties, e.g.,
> attributes to maintain with each entry, color legends, etc. With a
> member password you can modify entries and their attributes, and with a
> viewer password you can just see details without the ability to modify
> anything. A casual user can just see the map with the markers and their
> names, without access to any details for the entries. Hence
> distributing the member password to the group and having each person 
> add his or her details would be a good way to go. The number of points
> for Postgresql users can, of course, go pretty high. So far, we have
> seen reasonable performance with up to 500-600 markers. I don't know if
> there is an easy way of partitioning the user base into segments that
> can fit within this range. Another idea would be to just split the map
> after say 500 points.
>
> For the number (2) the choice seems to be between Google Maps vs.
> Mapserver and its associated Open Source tools. Having looked at
> Brent's follow up emails, it seems that Mapserver and associated
> toolkits can give much more flexibility.  Plus they have the advantage
> that we are not limited by Google's terms, the most annoying of which
> is that you cannot save, copy, or distribute the map images created.
> So, it seems best to move towards the Open Source alternatives,
> specially since they have better images as Brent points out. I've been
> looking at some of the Mapserver toolkits, and there seems to be an
> overwhelming amount of choice available for what to pick and not. So, I
> don't feel qualified to pick the right technologies to use for the base
> implementation. If someone can pick the mantle on that, I'd be happy to
> work with that person to see how we can exchange information from the
> map points stored from (1). If for the time being you feel comfortable
> continuing with Google Maps, then there's multiple ways we can share
> information developed by (1) through some kind of a web service API.
>
> Claire