Accessibility of databases licensed under the ODCDBL

Some more food for thought on the Open Data Commons Database Licence. This time about obligations to make the database available, either as a part of an obligation under the parallel distribution language in Section 4.6b, or as a general obligation to make derivative databases (that must comply with the Share Alike language). This comment was on the OKFN list:

3. Making available derivative works

Similar to the previous point I also think one might want to make explicit that one cannot restrict access to the data by providing some form of limited interface (this might best go in s4.6). For
example someone might make a derivative DB but put it behind a search form that only allowed people a limited query rate. Thus I think it might be worthwhile to have something related to the ‘Access’ provision (no 1) of the OKD which states:

“The work shall be available as a whole and at no more than a reasonable reproduction cost, preferably downloading via the Internet without charge. The work must also be available in a convenient and modifiable form.”

(obviously this can’t apply to the work being licensed but it can be used as part of the share-alike provision to affect the behaviour of those making derivative works).

I wonder if there are some practical problems for such a clause, especially with really large databases. Isn’t a limited query rate necessary in some circumstances? If so, and it is a requirement that the database be available for download, isn’t that a pretty big burden for really large databases?

I would be interested to hear from anyone with a web services or technical background about what to watch out for in any restrictions on how (or if) the DB must be made available.