[xquery-talk] Re: The State of Native XML databases
sterini at gmail.com
Tue Aug 21 12:31:38 PDT 2007
The latest TigerLogic 3.0 from RainingData supports it.
On 8/21/07, Ronald Bourret <rpbourret at rpbourret.com> wrote:
> Does anybody know how many native XML databases actually support
> node-level locking? My impression is that most support document-level
> -- Ron
> Jeff Dexter wrote:
> > To be fair, document level locking granularity affects more than the "one
> > big document" use case, and it affects more than just throughput. XQuery
> > updates can and do span multiple documents in a collection within a single
> > update query and transaction, and if the best you have is document-level
> > locking then you run the very real risk of colliding or deadlocking with the
> > subset of documents another parallel update has chosen.
> > True, node-level locking doesn't necessarily solve this problem, as updates
> > can still contend for the same node subset, but it hopefully (drastically)
> > mitigates the incidence of such contention. As you point out, less time
> > waiting on locks means more throughput, but it can also mean the application
> > spending less cycles figuring out what to do when it can't acquire those
> > locks.
> talk at x-query.com
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