<div dir="ltr"><div class="gmail_extra">Francois,</div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Dec 15, 2015 at 11:55 AM, François Bonnarel <span dir="ltr"><<a href="mailto:francois.bonnarel@astro.unistra.fr" target="_blank">francois.bonnarel@astro.unistra.fr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">PS : I am not considering here any kind of serialisation of these
VO-DML decscriptions (Object relational maaping, VOTABLE Mapping,
specific-stc2-xml-schema xml documents, json, etc... ). this is
another story but the initial VO-DML description will constraint the
solution. </blockquote></div><br>I mostly agree. However, one of the benefits of VO-DML is to have a language that can easily be mapped to a variety of contexts, including OO languages and relational databases, and so ORM. If variable length arrays were impossible (or very hard) to treat in ORM, then they should be left off the language, because they would be impossible (or very hard) to treat in a fundamental set of implementations.</div><div class="gmail_extra"><br></div><div class="gmail_extra">But yes, the implementation details of how to map VO-DML model instances to a serialization is a different topic. So for instance, a model might call for a great number of Object Type instances, but specific serialization or representation formats might allow more efficiency, whether we are talking about Java objects or SQL tables, or FITS. An image might have, in principle, an Object Type representation for each pixel in an image, but a FITS representation might factor out all the common metadata into a single representation for all the pixel in the image. I say in principle because I am not sure I can take a side in the modeling part per se, so I don't have an opinion on whether a pixel should be an Object Type or a Data Type, in this example.</div><div class="gmail_extra"><br></div><div class="gmail_extra">Omar.</div><div class="gmail_extra"><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr">Omar Laurino<br>Smithsonian Astrophysical Observatory<br>Harvard-Smithsonian Center for Astrophysics<div><font color="#999999">100 Acorn Park Dr. R-377 MS-81</font></div><div><font color="#999999">02140 Cambridge, MA</font><br><span style="color:rgb(153,153,153)"><a value="+16174957227" style="color:rgb(17,85,204)">(617) 495-7227</a></span></div></div></div>
</div></div>