[OAI-implementers] Resumption Tokens

Charles, Daphne daphne.charles@english-heritage.org.uk
Thu, 20 Feb 2003 11:32:56 -0000

Hi Folks,

Can any one help with my understanding of how Resumption Tokens work?

The resumption token may be expected in the response whenever the list of
records which might be returned exceeds a maximum no. of returns set by the
repository.  The original request may include other arguments.  However,
since the resumption token is an exclusive argument, it cannot then be
issued as part of a request with any other argument, so unless the value of
the resumption token includes the original request, then the list of records
returned has lost its context.

In the v.2.0 documentation the examples show a ListIdentifiers request with
from, set and metadataPrefix arguments.  A set of records is issued in
response, together with a resumption token which includes attribute names
and values for completeListSize and cursor.  So far so good.

However, when this resumption token is subsequently reused in a new request
it contains only a value of xxx45abttyz and has lost the completeListSize
and cursor attributes as well as the other arguments used in the original
request.  My question is, how can the repository reconstruct all this from a
resumption token value of xxx45abttyz in order to provide a set of records
which logically continues from the previous list?

Hoping for enlightenment!

Daphne Charles