SRU Implementors:
The OASIS Search Web Services Technical Committee (SWS TC) invites your
participation in the development of SRU/CQL 2.0.
We have begun accumulating suggestions for 2.0 features; additional
suggestions are welcome. We are also currently gathering requirements for
geospatial and LOM applications.
Among the suggested 2.0 features are:
1. Allow Non-XML Record Representations
Many formats do not map easily into XML, for example multimedia, images, and
even complex text formats. The suggestion is to allow non-xml serialized
data in the response, as well as value by reference. These would be signaled
by additional values for the recordPacking parameter. For example
recordPacking="base64" or recordPacking="uri".
2. Proximity
deprecate the PROX BOOLEAN operator and instead represent proximity by two
methods:
-- Adding a relation: 'window'.
examples:
* dc.title window/distance<5/unit=word "fries salt vinegar"
(fries, salt, and vinegar all within a span of 5 words)
*dc.title window/distance<5/unit=word ((fish and fries) and (salt or
vinegar))
(fish and chips and one of salt or vinegar, in a 5 word window)
* dc.title window/distance=2/unit=word/ordered "fries salt "
(fries followed by salt with 2 words between)
-- Adding a boolean modifier 'prox' which acts the same as the current
boolean, however can be attached to either AND (the current style of
proximity) or NOT for negative proximity.
Example:
* "fish and" not/prox chips
("fish and" followed by anything other than chips)
3. Faceted Searching ("scan" a result set)
One might search a library database for books about a particular topic, and
then see how many records there are in different time period
4. Result Set Size
Allow the client to indicate how much effort the server should take to
determine or estimate the number of records in the result set. Similarly,
allow the response to estimate accuracy of the result-set-size reported.
The server may be able to determine the exact number of records, or provide
a realistic estimate, but it may be an expensive process. The server might
prefer not go through that process unless the client requests that it does
so. Or the client might want to explicitly request that the server go
through, or not go through, that process. The client might want the first 10
records, or any 10 records, regardless of how many records there are. In
that case if the server goes through the process of determining how many
records there are, it may go through an expensive process for nothing. There
is also the special case where the server cannot determine or estimate the
number of records in the result set. In that case it might be useful to have
a special value or some way to indicate this condition.
5. Multiple Query Types
CQL is currently the only query type used by SRU but there could be other
query types as well, for example, Parameterized Query and XQuery.
6. Eliminate the Version and Operation Parameters
These two parameters are based on the assumption that the same base URL
might be used for different operations and versions. Instead, different base
URLs should be used.
7. Alternative Response Formats
Allow the client to request that the response be supplied in a specific
format, for example ATOM.
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We invite those interested in the development of 2.0 to join the committee.
However all of these (and further) proposed features will be discussed on
this list, as well as on the public OASIS listserv for the Committee. So if
you are unable to join the committee there is still ample opportunity to
participate.
Rob Sanderson will be the lead Technical Committee member for this 2.0
activity.
--Ray Denenberg
