[rus-wg] RUS Specification - operation results

[Steven Newhouse]

> The extract/fetch operations seem to return one or more full
> RUSUsageRecords, would it be sensible to add parallel operations that return
> just the ids?

I think you identify a need for just a single additional operation.

RUS::extractRecordsRUSId
INPUT: XPath/XQuery
OUTPUT: List of RUSIds

The existing operation RUS::extractSpecificRecords could then be used to 
extract the relevant records.

Following the initial extraction of the RUS Ids what would the client do 
with them? As there is no meta-data other than the ID one of the few 
things would seem to iterate over them to retrieve specific records in turn.

The list of RUSIds from one search operation could be compared to that 
of another... but then the two queries could be merged into one to yield 
the required (from the combined query) records in one go.

> The would be more efficient when the purpose is just to
> determine existence and not necessarily examine contents.

Do you have additional use cases in mind as to what you would do with 
the resulting RUSIds?

> On a related note, I don't know XPath/XQuery well but I assume that it is
> possible to do something like "extract all records that have been created in
> the last month". Is this correct?

As the initial timestamp element in the RecordHistory follows a standard 
format it should be searchable by XPath/Xquery... but I'm not an expert 
in this.

Can anyone clarify what XPath/XQuery can dow with timestamps?

Steven

-- 
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Dr Steven Newhouse                        Tel:+44 (0)2380 598789
Deputy Director, Open Middleware Infrastructure Institute (OMII)
Suite 6005, Faraday Building (B21), Highfield Campus,
Southampton University, Highfield, Southampton, SO17 1BJ,  UK