On Fri, Apr 29, 2011 at 3:19 PM, Paolo Crosato <span dir="ltr"><<a href="mailto:paolo.crosato@ubiest.com">paolo.crosato@ubiest.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
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Hi,<br>
<br>
I work for an LBS based company, we have our own proprietary
rendering engine for producing maps, and we work mainly with data
from Navteq and Teleatlas. Presently our rendering engine is behind
the competition in terms of visual quality (we have a bad support
for antialiasing, label names with both native and transliterate
names are missing, and so on). Introducing new features in our
current rendering architecture would require quite a lot of coding
and re-engineering, so we are looking for alternative renderers,
possibly open sourced. During this research project I came across
Mapserver, and it seems it would suit our needs in terms of high
quality rendering and customization.<br>
However, there are still some open issues, mainly questions, I'd
like to ask.<br>
<br>
In regards to rendering:<br>
1) Is there any way to align labels in different encondings for the
same city? I mean something like writing Москва́ and <i>Moskvá </i>vertically
aligned, like on Google Maps.<br>
2) Is there any plan to support 2.5D rendering for buildings?<br>
<br>
In regards to working with high loads of data:<br>
1) We render our maps from data provided by vendors like Navteq, and
they have a lot of details and features. Is there anyone working in
the same field, who could share some of his experience?<br>
2) Is it more efficient to work with PostGis/Oracle Spatial or with
shapefiles? I suppose the former would be faster, since shapefiles
provided by Navteq would require about 100gigs for Europe only, just
to store the data. <br></div></blockquote><div><br></div><div>As Thomas said probably a database like Postgis or Oracle (if your budget allows for the hefty license fee) is a sensible choice because it makes complex manipulations (like adding a translation for a label) easy.</div>
<meta http-equiv="content-type" content="text/html; charset=utf-8"><div>In that case a machine dedicated to the db backend with a fast network (GB or better) link to the rendering workstation is also *probably* recommended to free CPU resources and memory (for caching resultsets) on the rendering side (but that depends on your queries).</div>
<div>If a query is particularly CPU or I/O intensive consider using a materialized view instead (Oracle has builtin support, postgres not yet but it can be done).</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
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3) In regards to the hardware, I reckon we would need at least one
workstation dedicated to rendering. Currently we are hosting our
rendering service on dual Xeon (quad core), with 16G of ram and SAS
arrays of hard disks, would one server like this be ok or would it
be better to have more machines, especially if planning to use RDBMS
to hold the data? I'm asking this because with currently work with
detailed data from Europe, North and South America, so it's quite a
lot of stuff :)<br></div></blockquote><div><br></div><div>One issue to consider (might not be critical, just informing you) is that mapserver will perform the layer rendering serially.</div><div>Another is that disks are only involved when it is writing the image to a file so I would also think about saving money on disks and get more servers instead or use a fast primary for file generation (think SSD) and then move them async'ly to a slower (but cheaper) storage (think NFS).</div>
<div>Last: too much ram might never get used because of the cpu bottleneck kicking in before so I would also make sure that I could shuffle ram around if necessary (i.e.: one server's CPUs are consistently maxed out, but memory isn't: in that case I would buy a new server and move memory to the new one instead of buying more and waste it).</div>
<div><br></div><div>HTH,</div><div>Umberto</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div bgcolor="#ffffff" text="#000000">
<br>
Thanks in advance for any feedback.<br>
<br>
Regards,<br>
<br>
Paolo Crosato<br>
<pre cols="72">--
Paolo Crosato
Ubiest SPA
<a href="http://www.ubiest.com" target="_blank">http://www.ubiest.com</a>
</pre>
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