On Mon, 29 Mar 2004, Masatoshi OHISHI wrote:
> > o ADQL is a lower level technology we would like to integrate into
> > the DAL services to allow more complex queries. Maybe I am just
> > misreading the diagram, but it appears to suggest ADQL is specific
> > to the registry. (ADQL and data models can in principle be used
> > all over the middle level; maybe that is what the think and thick
> > arrow are supposed to signify).
>
> In the synthesized diagram, "standard queries" are use to communicate
> between the "Portals and so on" layer and the "Data Services" layer.
> This should be replaced with ADQL (x/s). Here ADQL/s stands for
> a string form of ADQL and ADQL/x for an XML form of ADQL, and
> both are basically identical. Since we agreed to use ADQL/x for communications
> between machines, "OpenSkyQuery/ADQL" in the middle of the diagram
> should be replaced with "ADQL/x".
For DAL we want ADQL queries, however I think there will be a continuing need for simpler parameter-oriented (HTTP GET/POST or WS) queries as well. In the future a full-up service would support both. Limited services would only be required to support the parameter style query. Parameter queries are simple, but can also be customized for each individual service. Both of these can be described as standard queries, i.e., they will be defined by the standard service protocol.