On 3/1/06, Roger Hyam < roger@tdwg.org> wrote:

This is a little more of a controversial question that has been suggested:

"Why should data providers supply search and query services?"
We have many potential data providers (potentially every collection and institution).
We have many potential data consumers (potentially every researcher with a laptop).
We have a few potential data indexers (GBIF, ORBIS , etc + others to come).
The implementation burden should therefore be:
Light for the providers - who's role is to conserve data and physical objects.
Light for the consumer - who's role is to do research not mess with data handling.

Heavy for the indexers - who's core business is making the data accessible.
Data providers should give the objects they curate GUIDs. This is important because it stamps their ownership (and responsibility) on that piece of data. They then need to run an LSID service that serves the (meta)data for the objects they own. There work should stop at this point! They should not have to implement search and query services. They should not anticipate what people will require by way of data access - that is a separate function.

Data consumers should be able to access indexing services that pool information from multiple data providers. They should not have to run federated queries across multiple data providers or have to discover providers as this is complex and difficult (though they may want to browse round data providers like they would browse links on web pages). Once they have retrieved the GUIDs of the objects they are interested in from the indexers they may want to call the data providers for more detailed information.

Data indexers should crawl the data exposed by the providers and index them in thematic ways. e.g. provide geographic or taxon focused services. This is a complex job as it involves doing clever, innovative things with data and optimization of searches etc.

Currently we are trying to make every data provider support searching and querying when the consumers aren't really interested in querying or searching individual providers - they want to search thematically across providers.

If a big data provider wants to provide search and query then they can set themselves up as both a provider and an indexer - which is more or less what everyone is forced to do now - but the functions are separate.

Data providers would have to implement a little more than just an LSID resolver services for this to work. They would need to provide a single web service method (URL call) that allowed indexers to get lists of LSIDs they hold that have had their (meta)data modified since a certain date but this would be a relatively simple thing compared with providing arbitrary query facilities.

I believe (though I haven't done a thorough analysis of log data ) that this is more or less the situation now. Data providers implement complete DiGIR or BioCASE protocols but are only queried in a limited way by portal engines. Consumers go directly to portals for their data discovery. So why implement full search and query at the data provider nodes of the network (possibly the hardest thing we have to do) when it may not be used?

This may be controversial. What do you think?

I'm not sure about controversial, but I am pretty sure that what you are pointing at is a warehouse model. I don't know if I am prepared to agree that all possible present and future concerns of TDWG can be answered by data warehouses. In particular, if you analyse log data of a warehouse, it won't be too surprising if the conclusion is that users are behaving as though they mainly need a warehouse. [To data consumers a warehouse and a portal are indistinguishable. I think.]

Bob Morris