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<DIV><FONT face=Arial size=2><SPAN class=120523008-09102009>Hi
all,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=120523008-09102009>After the
meeting in Hamburg </SPAN>I had some thoughts about Steve Hankin's talk on
server-side processing.</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>As I said at the meeting I believe encoding
expressions into a URL is<BR>going to become increasingly restrictive as the
expression syntax gets<BR>more complex. Apart from the sheer length of
URLs there will be the<BR>issue of grammar and encoding. For instance you
if want to refer to<BR>other OPeNDAP resources you would have to embed one URL
in another,<BR>requiring quoting, escaping, etc. This could get very
complex and run<BR>into problems of multiply escaped characters. I've seen
it happen in<BR>other web services.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>If we want to build on tools and standards that our
community already<BR>use I would recommend extending NcML to include processing
tags and<BR>developing services that accept NcML as input (for instance as
the<BR>body of a HTTP POST or PUT). You could imagine a very RESTful
system<BR>where a server allows new virtual datasets to be created by
PUTing<BR>NcML. The result of such a PUT could either be NcML on the
server<BR>that constructs the virtual dataset on demand or the NcML could
be<BR>"executed" on the server to create a NetCDF.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>I only have a shallow knowledge of NcML so I don't
know to what extent<BR>this is being done already. In TDS has NcML been
used to describe virtual<BR>datasets other than aggregations?</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Cheers,<BR>Stephen.</FONT></DIV>
<DIV> </DIV>
<DIV align=left><FONT face=Arial size=2>---</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Stephen Pascoe +44 (0)1235
445980</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>British Atmospheric Data
Centre</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Rutherford Appleton
Laboratory</FONT></DIV>
<DIV> </DIV>
<br><p>--
<BR>Scanned by iCritical.
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