>-----Oorspronkelijk bericht----- >Van: SRU (Search and Retrieve Via URL) Implementors [mailto:[log in to unmask]] >Namens Ray Denenberg, Library of Congress >Verzonden: vrijdag 10 augustus 2007 15:55 >Aan: [log in to unmask] >Onderwerp: Re: numberOfRecords > >> From: "Theo van Veen" <[log in to unmask]> >> Wouldn't it be much simpler to use the contents of numberOfRecords to >> indicate that there the number or exact number is unknown rather than >> introducing a new extension ... > >The use case we were addressing is when the server may be able to determine >(or estimate) the number of records, but it is an expensive process, so the >server would rather not go through that process without the client request >that it do so. (The client might only want the first 10 records regardless >of how many there are. In that case if the server goes through the process >of determining how many records there are, it goes through an expensive >process for nothing.) > >The case where the server cannot determine or estimate the number is a >special case. In that case it would, as you suggest. be useful to have a >special value or some way to indicate this condition. But it is really the >first (more general) case that generated discussion of an extension. > I see, but in this case the client has to have pre-knowledge about the server. I consider interoperability as minimizing the need for pre-knowledge. In this case I would do it the opposite way: the server doesn't send the numberOfRecords and the client can request by extension "please give me the numberOfRecords anyway" rather than let the client say "I don't care about the numberOfRecords so don't send a diagnostic". Theo