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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>MapGuide SP1 (1.1.0) which is about to be
released has schema caching (DescribeSchema, GetSpatialContext, etc…) and
FDO connection pooling. It is a lot faster then release 1.0.1. The code is
already available in the open source branch, but has not been back ported to
the trunk yet.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Bruce<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <st1:PersonName
w:st="on">Traian Stanev</st1:PersonName> <br>
<b><span style='font-weight:bold'>Sent:</span></b> September 19, 2006 3:49 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">dev@mapguide.osgeo.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [mapguide-dev]
DescribeSchema</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Well, short of storing the FDO schema in
an SDF provider-like blob between connections, I don't have any other
ideas on how to make DescribeSchema faster in 1.0.1. :-)</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Haris
Kurtagic [mailto:haris@sl-king.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, September 19, 2006
5:40 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">dev@mapguide.osgeo.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [mapguide-dev]
DescribeSchema</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Thank you.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>I am not just "looking" in
instances of call. I've done a quite a few testing and MG server does call
DescribeSchema very often (refresh, layer on, api calls etc...)</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Caching inside connection doesn't help in
1.0.1 (because 1.0.1 is not pooling connections).</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>thank you for suggestions and
explanations.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Haris</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <st1:PersonName
w:st="on">Traian Stanev</st1:PersonName> [mailto:traian.stanev@autodesk.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, September 19, 2006
11:18 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">dev@mapguide.osgeo.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [mapguide-dev]
DescribeSchema</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>The fact that there are several instances
of calls to DescribeSchema does not imply that that code actually gets called a
lot during normal operation of MapGuide. This is because the FeatureService is
an API more than anything else.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Personally, I would accept the fact that
in a multithreaded environment, an operation might fail if the schema changes
underneath it and would simply cache the schema once per open FDO connection,
but that's my personal opinion. Another option is to have some sort of a
"read-only" flag on the connection which you can use to determine
whether to cache the schema or not.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Traian</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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face="Times New Roman"><span style='font-size:12.0pt'>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Haris
Kurtagic [mailto:haris@sl-king.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, September 19, 2006
4:59 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">dev@mapguide.osgeo.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [mapguide-dev]
DescribeSchema</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>What I was trying to say is that MapGuide
server itself (server feature service) is calling many times this command in
fdo.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>And also after getting it is doing a lot
of "copying and.." and it takes a lot of time MapGuide itself..</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>So If I cache it inside FDO provider it is
little better, but not sure also is it "right" to cache. In multithreaded
enviroment I could imagine some problems if schema is changing.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>I am using 1.0.1 version.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Haris</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <st1:PersonName
w:st="on">Traian Stanev</st1:PersonName> [mailto:traian.stanev@autodesk.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, September 19, 2006
10:52 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">dev@mapguide.osgeo.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [mapguide-dev]
DescribeSchema</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>You are right. DescribeSchema is a major
choke point for any code that calls it a lot. It should be cached whenever
possible. That said, MapGuide is going to (or already has) some caching of the
schemas, so it's not that critical for the provider to have a fast
DescribeSchema, unless you are worried about code other than MapGuide.
However, I would argue that competently written FDO code already
avoids repeated calls to things like:</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'> * DescribeSchema</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'> * GetSpatialContexts</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'> *
FdoIFeatureReader::GetClassDefinition</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'> * anything that converts FDO
stuff to XML.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Traian</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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face="Times New Roman"><span style='font-size:12.0pt'>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Haris
Kurtagic [mailto:haris@sl-king.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, September 19, 2006
4:25 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">dev@mapguide.osgeo.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> [mapguide-dev] DescribeSchema</span></font><o:p></o:p></p>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi,</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Right now FDO command DescribeSchema is called many times
while describing Data Store and in another cases.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I have a question how should fdo provider react to this
requests.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Is it supposed that provider will cach schema or is it supposed
to allow dinamicaly changing of schema (in underlaying RDBMS for example) or ..
?</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Also as I see it, there is a lot of coping of fdo schema
returned from provider inside server, so it is very time consuming.</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Not sure if I am looking right but it doesn't look good :)</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Haris</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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