[OAI-implementers] Selective Harvesting and Datestamps

[Martijn Faassen]

Simeon Warner wrote:
> 
> On Thu, 9 Jun 2005, Martijn Faassen wrote:
> 
>>I'm implementing an OAI server and am wondering about the details of
>>selective harvesting in date ranges.
>>
>>The spec says:
>>
>>   modification - the response *must* include records, corresponding to
>>   the metadataPrefix argument, which have changed within the bounds of
>>   the from and until arguments.
>>
>>Does this mean that records need to track their full history of modified
>>dates? Just tracking their last modified datestamp does not seem enough
>>to fully comply with this, as a record modified on 2005-04-10 and then
>>again on 2005-06-05 would not show up in the range 2005-03-01 -
>>2005-05-01, as it would only be known it was modified 2005-06-05.
>  
> It was intended to mean only the most recent changes. Thus, only the last
> modification date for each record needs to be recorded. Looking at the
> spec I see it is only implied that records have a single datestamp
> associated with them:
> 
> spec> ... A repository must update the datestamp of a record if a change
> spec> occurs, the result of which would be a change to the metadata part
> spec> of the XML-encoding of the record. Such changes include, but
> spec> are not limited to, changes to the metadata of the record, changes
> spec> to the metadata format of the record, introduction of a new
> spec> metadata format, termination of support for a metadata format, etc

Right, I saw vague hints that this was the case, and I couldn't imagine 
it being otherwise, but a strict reading of the spec implies otherwise. 
Perhaps a clarification can be added to the implemention guidelines.

Thanks!

Regards,

Martijn