IVOA WG data access layer

[Markus Dolensky]

It was mentioned before, but conceptually VOQL appears to be closer to 
an extension of an SQL-kind of query language whereas DAL will deal with 
things like

- how to turn info harvested from a registry into a VOQL query
- how to perform transaction management of distributed queries
- error handling
- ?

Consequently, if VOQL returns tabular data then DAL has to have a method 
to transfer it to a scratch space where the results from other sub 
queries are assembled.

Markus


Tony Linde wrote:
> I think the DAL has to look at all types of access to data whether querying
> catalogues, accessing images, time series or spectra and any other type of
> data access.
> 
> Or is the split intended to be: 
> 
> . VOQL addresses access to tabular data
> 
> . DAL addresses access to non-tabular data
> 
> Might work.
> 
> Cheers,
> Tony.