A summary of the Scan discussion.
We need to be able to browse/scan. This was always known but not defined
* We need a new operation with new request/response.
- New Service: How to duplicate Explain? How to link from service to
- Adding to existing operaion: Ugh!
* Need to retrofit SRU with an operation field.
- Default is 'searchRetrieve', can be set to 'scan'.
index string The index on which to scan.
term string The term to scan around/at.
numRequested integer Number of terms in the response
termPosition integer Position of the term in the response
stepSize integer Terms omitted between consecutive in resp.
Do we need stepSize? (I've never used it)
term CQLtype CQL searchClause
xTerm XCQL:searchClauseType XCQL searchClause
numTerms integer aka numRequested
Position integer aka termPosition
Do we need position?
Yes :) Need it to cursor properly. Useful locations are:
term is before first/after last in response
term is first/last in response
term is centered in response
Also some interfaces have a set number before the term (eg 5) and then
user requested afterwards.
Splitting index and term is good, IMO. Otherwise what to do with the
Relation? Semantics of scan: dc.title > foo vs dc.title < foo ?
List [Array? ;)] of terms with following subfields:
alternativeTerms ( list of alternativeTerm? )
database / server address
CQL for direct access (index plus term)
Occurrence count of term in database, vs occs of term in Z39.50 scan)
In a library catalogue, scan indexes are typically of two types - those
that link directly to the bibliographic database and those that link
directly to the authority database and indirectly to the bibliographic
database. In the first case for each term there will be x (e.g. 12)
occurrences in the bibliographic database indicated by global occurrences.
One search, e.g. by internal identifier will retrieve the 12 occurrences
and nothing else.
In the second case there will be x occurrences (e.g. 2) in the authority
database indicated by global occurrences. Each authority record will also
have x occurrences in the bibliographic database.
,'/:. Rob Sanderson ([log in to unmask])
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