TAP document implementation issues. Section 2.6

[glemson]

Dear Pat and others
> Correcting myself: 
> 
> We can't actually do this since ADQL does not have a BOOLEAN type.  
> 
ADQL has a BIT type (that is, it has a reserved keyword of that name).
If I am not mistaken that datatype is often used for representing booleans.
You might want to take it in consideration. 

Cheers 

Gerard 

> We could follow ADQL region function style and use integer, with 1 meaning 
> true and 0 meaning false (CONTAINS and INTERSECTS return 0 or 1). 
> 
> Alternatively, we could use CHAR(1) with values T and F.  
> 
> In either case, VOTable does have boolean so this is likely to cause 
> confusion. The mapping table in sec 2.5 is bidirectional, but we cannot really 
> specify a bidirectional mapping of boolean.  
> 
> Maybe TAP just cannot support VOTable boolean type?  
> 
> Arbitrary decision: I will go with INTEGER and 0 or 1 (for the flags in 
> tap_schema.columns) and I will change the table in section 2.5 to say that 
> VOTable boolean is not supported by TAP unless there is strong input to do 
> something else (and very soon - see PS) 
> 
> thanks in advance for help/support/ideas, 
> 
> PS-My understanding is that TCG review has to start in the next couple of days 
> in order to be completed before the interop... so I will need some input or 
> will have to make an arbitrary decision in the next 24-36 hours. I also know 
> some people are travelling to ADASS in Japan and are likely off-line. 
> 
> --  
> 
> Patrick Dowler
> Tel/Tél: (250) 363-0044
> Canadian Astronomy Data Centre
> National Research Council Canada
> 5071 West Saanich Road
> Victoria, BC V9E 2M7 
> 
> Centre canadien de donnees astronomiques
> Conseil national de recherches Canada
> 5071, chemin West Saanich
> Victoria (C.-B.) V9E 2M7