vectorize astroquery.esa.hsa & HSA.download_data about astroquery

[keflavich]

@jkrick does the HSA archive allow multi-position queries? If it does, it is possible to support this - though we'd need help implementing it.

[bsipocz]

cc @jespinosaar

[jespinosaar]

Dear @jkrick , many thanks for your feedback.

I have been checking the options available and, indeed, table_upload is not currently supported. In the Archive UI (https://archives.esac.esa.int/hsa/whsa/) you can see we can upload a list of targets, but in the end what we are doing is simply resolving them, extracting their coordinates and then generating a query with several OR clauses, one for each pair of coordinates.

On the other hand, I really like the idea of vectorizing the methods included in the different modules, but please bear in mind also the limitations on the server and the DB about the length of the queries and the contents of the requests (thinking on millions of different elements). I think that searching for such amount of data is easier if you just execute a for loop over a table of results, so the results are extracted one by one. You can control what is done between each iteration and it is easier and faster for the server to handle small requests.

Please let me know if you have further doubts.