TAP VOSI Information

[Gretchen Greene]

this is good news,  thank you, Mark and Tom for the feedback.

---- Original message ----
>Date: Tue, 24 Nov 2009 09:35:07 -0800
>From: Patrick Dowler <patrick.dowler at nrc-cnrc.gc.ca>  
>Subject: Re: TAP VOSI Information  
>To: dal at ivoa.net
>
>On Tuesday 24 November 2009 05:20:07 Tom McGlynn wrote:
>> The current TAP specification is a bit unclear about this.  
The current 
>> draft doesn't mention VARBINARY data at all. 
>
>The TAP spec very explicitly mentioned VARBINARY and BLOB and 
how they are to 
>be described.
>
>A column of type VARBINARY is mapped as Mark said:
>
><FIELD datatype="unsignedByte" arraysize="*"  .... />
>
>and it would be correct to include xtype="adql:VARBINARY" as 
well. The service 
>could put something more specific for arraysize. Since the 
datatype and 
>arraysize are sufficient, the xtype is redundant in this case 
and could in 
>principle be used for something else; we debated this 
extensively and I did 
>bring up the idea of embedding a small image in the results 
but that idea 
>never got any traction...
>
>The only fields where xtype is required to be an adql-
specific value are
>TIMESTAMP, POINT, REGION. For those, datatype="char" and 
arraysize="*" but 
>they are not simply strings. What needs to be clear in the 
spec is that these 
>are the only cases where xtype is mandated. In other cases, 
both uploads and 
>results are sensible using the other field attributes.
>
>So, right now the TAP spec does not specify how to deal with 
an embedded 
>binary image; I think we should leave that to 1.x but I also 
think people 
>could experiment with using xtype without being non-compliant 
with the TAP 1.0 
>spec.
>
>-- 
>
>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