Prospective agenda for VOQL session in Madrid
Patricio F. Ortiz
pfo at star.le.ac.uk
Wed Sep 21 12:26:05 PDT 2005
On Wed, 21 Sep 2005, Maria A. Nieto-Santisteban wrote:
> I will take the liberty to answer
> > This sounds quite good for most of the problematic column names.
> > There is however, not a small number of columns (>1800) in the literature
> > with brackets in their names, eg, metal aboundances, forbidden or
> > semiforbidden transitions, etc. How are those cases supposed to be handled?
> It has been always agreed that services publishing data are responsible to
> be complaint with the protocols. Services providing access to catalogs
> with columns names including brackets and other funny characters will have
> to either change their names ( ;-) ) or hide with mapping procedures their
> original name.
Well, the example I picked up is from *vizier*, one of the key services
available today :-) :-) So it's not just a small, dark site in the
fringes of the VO.
> > The same question arises with table/column names differing just by
> > their case (lower/uppercase names) which should clearly be stated.
> to me this case is clear ... SQL is case insensitive. To my knowledge
> only mySQL working with linux make distinctions between upper and lower
> case which I consider a "bug".
Yes, that's SQL, but we are talking about ADQL here. The fact that a
number of sites use SQL to handle their databases, does not mean that
100% of the sites holding data for the VO will use it, therefore, it
seems to me a bit of a limitation that we make ADQL follow all SQL's
syntax and rules (which are not even "universal").
Remember, if these columns have "funny characters" or a combination of
upper and lower case, it is because their host systems can handle them,
which is what matters the most.
Column names are a bit of a sensitive issue, to an astronomer m_b and M_b
make a world of difference, there is a large "knowledge base" which
should be respected as much as possible by any exchange language.
My personal feeling is that ADQL should adapt to astronomers' needs and
reality (like the inclusion of XMATCH and other astronomy specific
syntax), and this applies to column/table names with "funny" characters
and case sensitivity rather to adapt to standards which few respect ;-)
Just my 2 cents,
Patricio F. Ortiz pfo at star.le.ac.uk
Department of Physics & Astronomy Phone: +44 (0)116 252 2015
University of Leicester
Leicester, LE1 7RH, UK
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