Woops realized that I simply responded to John.
Peter
--
Peter Cornillon
Graduate School of Oceanography - Telephone: (401) 874-6283
University of Rhode Island - FAX: (401) 874-6728
Narragansett RI 02882 USA - Internet: pcornillon@xxxxxxxxxxx--- Begin Message ---
Hi all,
An interesting discussion. I wrestled a bit with this around the time
of the DODS developers meeting last January. I have attached a table
that I put together to help me keep track of the issues. I think that
you have progressed way beyond this, but thought that you might find
it interesting anyway.
Peter
John Caron wrote:
>
> heres another strawman, incorporating our latest discussions:
>
> http://www.unidata.ucar.edu/projects/THREDDS/xml/InvCatalog.0.6d.dtd
>
> Recent changes:
>
> 1) Collections as datasets. Ethan and I think the cleanest way to allow
> "collections as datasets" is to allow nested datasets. Collections remain
> just groups of datasets. A Collection as a dataset is done as a dataset with
> nested datasets. Nested dataset elements (Joe's meaning #2) should imply (in
> some way we need to clarify better) nested datasets (Joe's meaning #1 and
> #3).
>
> 2) allow compound services again. I have talked myself into that these will
> be often useful.
>
> 3) services are now contained within any collection, rather than having to
> be all in the top catalog element. They are scoped by the collection they
> are in (so we no longer use ID, since those are global). This makes a
> catalogRef have (almost) the same semantics as a collection.
>
> 4) a catalog now only has exactly one collection element. (i considered
> eliminating catalog but i think its better this way).
>
> 5) "attribute" changed to "property" (tired of saying "the attribute
> attribute")
>
> 6) access element can specify an absolute URL with a serverType -or- a
> reletive URL with a serverID.
>
> Unless I get a barrage of objections, I will document this in more detail
> ASAP. I will be gone for a week starting next Tuesdy, so Ethan will continue
> the conversation as needed. Hopefully, we can converge soon and take a
> break! I think I have incorporated all the good ideas i have heard in this
> discussion. Have I left out something, or do you think any feature is not
> worth the complexity?
--
Peter Cornillon
Graduate School of Oceanography - Telephone: (401) 874-6283
University of Rhode Island - FAX: (401) 874-6728
Narragansett RI 02882 USA - Internet: pcornillon@xxxxxxxxxxx<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="GENERATOR" content="Mozilla/4.72 [en] (X11; U; Linux
2.2.14-6.1.1 i686) [Netscape]">
<title>Oceanology International </title>
</head>
<BODY bgcolor="#eeeeee" vlink=blue>
<table width="100%" cellpadding=0 cellspacing=2><tr>
<td bgcolor="white"><a HREF="levels.html"><img
src="../dods-general/next.gif"></a></td>
<td bgcolor="white"><a HREF="definitions.html"><img
src="../dods-general/up.gif"></a></td>
<td bgcolor="white"><a HREF="definitions.html"><img
src="../dods-general/previous.gif"></a></td>
<td align="center" bgcolor="#99ccff" width="100%"><font size=7><b>OPeNDAP Data
Objects, Collections and
Sets</b></td></table>
<p><br><br>
<basefont size=6>
<p>
<ul>
<li> <font color="red">OPeNDAP Data Objects</font> are the data retrieved by
any OPeNDAP URL
(constrained or unconstrained).<br><br>
<ul><font color="magenta">
<li>a portion of a satellite image
<li>a mooring record
</font>
</ul><br>
<li> <font color="red">OPeNDAP Datasets</font> <font color=green>(or OPeNDAP
Granules)</font>
are OPeNDAP Data Objects accessed by an unconstrained URL.<br><br>
<ul><font color="magenta">
<li>a satellite image
<li>a mooring record
<li>a NetCDF file that contains all satellite images in a given
projection from a specific sensor
</font>
</ul><br>
<li> <font color="red">OPeNDAP Data Collections</font> are collections of
OPeNDAP
Datasets that are accessible either <br>
<ul type=i>
<li> as a new OPeNDAP Dataset via an OPeNDAP Aggregation Server, or<br>
<li> as a list of OPeNDAP Datasets via a File Server.<br><br>
</ul>
<ul><font color="magenta">
<li> all satellite images in a given projection from a specific
sensor
<li> a collection of mooring records
</font>
</ul><br>
<font color=green>Note that the list of OPeNDAP Datasets accessed via
an unconstrained
request to an OPeNDAP File Server is also an OPeNDAP
Dataset.</font><br><br>
<li> <font color="red"><blink>NVODS Datasets</blink></font> are all of the
meteorological
or oceanographic data at a site that the data provider considers to be
logically
connected. Could be an OPeNDAP Dataset, an OPeNDAP Data Collection or a
group of
OPeNDAP Datasets that are not formally linked from an OPeNDAP
perspective.<br><br>
<ul><font color="magenta">
<li> all satellite images in a given projection from a specific
sensor for which
neither an OPeNDAP File Server nor an OPeNDAP Aggregation
Server exist<br>
<li> a NetCDF file that contains all satellite images in a given
projection
</font>
</ul>
</BODY>
</HTML>
--- End Message ---
