BAND question

[Doug Tody]

This is reasonable; the only question is whether to ask the client or the
server to deal with issues such as range-list ordering.  Since the server
has to use the list it probably has to be able to deal with this sort
of thing anyway, in order to be robust.  Hence, this should be at most
a SHOULD.

Regarding what constitutes a match, probably any intersection qualifies
as a match.  This is the usual rule.  SIA defined an INTERSECT parameter
to try to define this more carefully, but I don't think it has been used
very much, so a simple rule is probably preferable.   - Doug


On Thu, 18 May 2006, Markus Dolensky wrote:

> Hi Alberto, Doug,
>
> ... good point. In order to tackle this and another comment received in the DAL
> session this week I'd like to put another gray box with a note to section 7.4
> which deals with ordered lists and the issue of boundaries:
>
> "Interval and range list query paramaters SHOULD be ordered monotonically.
> Interval boundaries are included in the search range. A service SHOULD return
> any record inside or just overlapping the search interval. A service SHOULD err
> on the side of inclusion thereby leaving the ultimate decision to the consumer
> whether to select it for retrieval. A service MAY truncate or compute data to
> match the exact boundaries."
>
>
> One may argue for turning the SHOULDs into MUSTs but this would give service
> providers no means to exlude items from a result which would otherwise be
> deemend unreasonable for one reason or another. One could also be more specific
> depending on the type of data (atlas vs modeled), but I'm not sure being more
> verbose is useful.
>
> Cheers,
> Markus
>
>
> Quoting Markus Dolensky <Markus.Dolensky at eso.org>:
>
> > Quoting Alberto Micol <Alberto.Micol at eso.org>:
> >
> > >
> > > Hi Doug,
> > >
> > > I was trying to understand how I should
> > > implement the search engine using the BAND parameter.
> > >
> > > Suppose that the query says BAND := 5E-7/5.5E-7
> > >
> > > I do have datasets in my archive with a bandpass extending from
> > > 4.8E-7 to 5.1E-7
> > > and others with a bandpass going from 5.1E-7 to 5.4E-7.
> > >
> > > The first set of datasets hence have a bandpass that intersects the
> > > required one,
> > > while the second set has a bandpass that is fully immersed into the
> > > required BAND.
> > >
> > > Which ones should I return? Both or only the second set?
> > > That is, does intersection suffice?
> > >
> > > Or instead should simply be the typical wavelength (central
> > > wavelength however defined)
> > > that should match the constraint? (in which case some datasets of my
> > > first set might
> > > match and others might not if their central wavelength is defined
> > > differently)
> > >
> > > So, shall the data provider work with BOUNDS or LOCATIONs (in char
> > > speak) to answer
> > > a BAND query?
> > >
> > > Whatever the answer, it would be useful to describe this in the
> > > document,
> > > so that we get consistent results from different data centres.
> > >
> > > Thanks,
> > >
> > > Alberto
> > >
> >
> >
>
>