[SIAv2] query params

[Patrick Dowler]

The effect of the proposal is to fold SIZE into the POS parameter by 
having geometry values instead of a separate SIZE parameter, so SIZE 
would go away. This is consistent with having ranges for BAND and TIME 
instead of a single value and a "width" parameter.

It also removes the use of STC-S from query parameters (with the intent 
of also not using STC-S in AccessData and eventually not including 
coordinate metadata in ADQL values either as it is generally agreed that 
conflating data and metadata in that way was a bad idea).

In those geometry values, we could well define both RANGE and BOX types 
as they serve different purposes; they behave differently but 
predictably at the poles.

I have preserved the range syntax from SSA and predecessors, but there 
is no support for "range lists": when developing DALI we explicitly 
discussed lists of values are agreed that multiple values would be done 
with multiple parameter=value pairs instead.

Hope that helps to clarify it.


Pat

On 11/13/2013 02:08 PM, Douglas Tody wrote:
> The proposal here appears to be that POS,SIZE,BAND,TIME,POL, and in
> particular POS, could be generalized sufficiently so that we can drop
> the REGION parameter (REGION being an STC-S string that an optionally
> replace POS,SIZE,BAND,TIME,POL as the specify the filter term).  I will
> ignore the issue of REGION for the moment, but agree strongly that
> having things already broken out as in POS,SIZE,BAND,TIME,POL makes
> service implementation simpler, and extends well to capabilities such as
> range-list values.

-- 

Patrick Dowler
Canadian Astronomy Data Centre
National Research Council Canada
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