new TAP-1.1 WD released

[Mark Taylor]

Dave,

On Mon, 31 Jul 2017, Dave Morris wrote:

> On 2017-07-20 00:30, Mark Taylor wrote:
> > 
> >     Similarly, mandating "*" as the arraysize value for the
> >     various character data columns in these tables is
> >     unnecessarily restrictive; there's no reason that
> >     services should not return fixed-width character array
> >     columns here if they want to.
> 
> For individual services I agree, but this could cause problems when uploading
> data from one service into another.
> 
> If service A defines column_name as CHAR[10] and service B defines it as
> CHAR[8], if a uses takes a VOTable result from A and uploads it into B then
> the column names could get truncated and the query could fail.
> 
> Allowing different services to have different size limits places the burden on
> the end user to check that they are all interoperable.

I don't think that follows.

For one thing, the metadata (including column names) of uploaded tables 
are not reported in the TAP_SCHEMA tables.

But in any case, the way that a service defines its TAP_SCHEMA
tables is independent from any limits it may have on column name
length in uploaded tables.
Just because a service reports its column names with arraysize='10' does
not mean that it won't accept uploaded tables with 11-character column
names.  Conversely, reporting column names with arraysize='*' does not
guarantee that it will accept uploaded tables with column names
of unlimited length.

Mark

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/