New helper query interface method

[KevinBenson]

As you say Matthew there is a GetRecord, but I don't know of a identifiers
one except "ListIdentifiers", but the way I understand it people were
wanting to get identifiers based around a query.  ListIdentifiers just has a
few restrictions such as set or date, but not any kind of search constraint.
But I am no OAI expert, so maybe there is another way to do another OAI
verb.

Also this might rely on a client app now having to understand in OAI format
plus possibly having to switch to different endpoints when doing there
queries into the registry.

I would prefer to keep in the search interface, but I probably could be
convinced otherwise.

Cheers,
Kevin

-----Original Message-----
From: owner-registry at eso.org [mailto:owner-registry at eso.org]On Behalf Of
Matthew J. Graham
Sent: 14 April 2005 16:16
To: Guy Rixon
Cc: KevinBenson; Paul Harrison; 'Registry List'; Tony Linde
Subject: Re: New helper query interface method


Hi

> If we have the query that just returns the list of identifiers, and we
> have
> the query that returns the document for one identifier, then we
> wouldn't need
> a paging arrangement; the client could do the paging by calling down
> the
> documents one by one by identifier. This would be a lot simpler.

Both "queries" are available through the OAI interface (which all
harvestable registries need to support) which can also support the
resumptionToken idea so that registry providers can set their own
paging limits.
	Cheers,

	Matthew


> On Thu, 14 Apr 2005, Paul Harrison wrote:
>
>> KevinBenson wrote:
>>>> From what I could tell from Yuji e-mail the main thing is about not
>>> returning so much data all at once to the client.  Somebody a long
>>> time ago
>>> mentioned a resumptionToken or pagingID concept on the query/search.
>>>  I
>>> think this is something that would be good and needed.  So you could
>>> page
>>> through your query results.  That way you might not return thousands
>>> at a
>>> time, but a certain amount and let the client page through all the
>>> results
>>> with the registry web service.  A user may send a global query; not
>>> even
>>> sure if we could handle returning 11,000 resources at once, so this
>>> is
>>> something we should look into.  The idea would be is to return a
>>> pagingID
>>> then a client who wants to see more would send it back again to the
>>> registry
>>> web service to get the next set of Resources.
>>
>> This is a good idea that is worth considering..
>>>
>>> Cheers,
>>> Kevin
>>>
>>> FYI, I will say Astrogrid does use a maxcount kind of property, so
>>> that is
>>> the maximum number of resources that is returned from the registry.
>>> But
>>> having a paging system would be nicer in case a user wants to see
>>> more
>>> results.
>>
>> A max return count that is set on the server is a bad idea - we have
>> spend time tearing our hair out in the past wondering why a resource
>> was
>> not returned, when it had been cut off silently by such a mechanism..
>>
>>>
>>> -----Original Message-----
>>> From: owner-registry at eso.org [mailto:owner-registry at eso.org]On
>>> Behalf Of
>>> Tony Linde
>>> Sent: 14 April 2005 08:27
>>> To: 'Registry List'
>>> Subject: RE: New helper query interface method
>>>
>>>
>>>
>>>> I also think that Yuji Shirasaki's idea of having a search
>>>> that returns a list of identifiers for a query is a
>>>> potentially good one, and possibly even a function that
>>>> returns the number of matches for a query.
>>>> - This could of course be done with a single query interface
>>>> function but with a slightly extended RQL
>>>
>>>
>>> Perhaps a flag indicating whether to return 'documents',
>>> 'identifiers' or
>>> 'count' on the query?
>>>
>>> T.
>>>
>>>
>>>> -----Original Message-----
>>>> From: owner-registry at eso.org [mailto:owner-registry at eso.org]
>>>> On Behalf Of Paul Harrison
>>>> Sent: 14 April 2005 08:15
>>>> To: Ray Plante
>>>> Cc: Registry List
>>>> Subject: Re: New helper query interface method
>>>>
>>>> Ray Plante wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>>
>>>>>
>>>>>> GetResource
>>>>>
>>>>>
>>>>> I think it would be good to have an explicit identifier resolver
>>>>> function, even though this is possible directly with the
>>>>
>>>> constraint-based search.
>>>>
>>>>> (In fact, we should define it as being equivalient to a search with
>>>>> the constraint "identifier='{ivo-id}'".)  An immediate use for this
>>>>> would be to check that an authority ID is not already registered;
>>>>> however, I can imagine other applications using this.
>>>>>
>>>>> On Wed, 13 Apr 2005, Matthew J. Graham wrote:
>>>>>
>>>>>
>>>>>> But this is exactly the same as the OAI GetRecord method?
>>>>>
>>>>>
>>>>> The proposal is to make it specifically part of the Search
>>>>
>>>> interface
>>>>
>>>>> (which should be independent of the Harvesting interface).
>>>>>
>>>>> cheers,
>>>>> Ray
>>>>>
>>>>
>>>> It would please me! -the majority of the queries that I want
>>>> to make are of this form, and it would save having to create
>>>> adql for the purpose....
>>>>
>>>> I also think that Yuji Shirasaki's idea of having a search
>>>> that returns a list of identifiers for a query is a
>>>> potentially good one, and possibly even a function that
>>>> returns the number of matches for a query.
>>>> - This could of course be done with a single query interface
>>>> function but with a slightly extended RQL
>>>>
>>>> Regards,
>>>> 	Paul.
>>>>
>>>> --
>>>> Paul Harrison
>>>> ESO Garching
>>>> www.eso.org
>>>>
>>>
>>>
>>>
>>>
>>
>>
>> --
>> Paul Harrison
>> ESO Garching
>> www.eso.org
>>
>
> Guy Rixon 				        gtr at ast.cam.ac.uk
> Institute of Astronomy   	                Tel: +44-1223-337542
> Madingley Road, Cambridge, UK, CB3 0HA		Fax: +44-1223-337523