[xquery-talk] Re: The State of Native XML databases

[Ronald Bourret]

There's an additional problem here.

If you're updating a particular node, you probably want to lock the 
ancestors of the node as well, so that nobody can delete them, as this 
would conflict with your update in a rather major way. Taken to an 
extreme, this effectively locks the entire document.

I'd be curious to know how node-locking (or page-locking) databases 
handle this problem. Perhaps there are "no-delete" locks placed on the 
ancestors?

-- Ron

Jeff Dexter wrote:
> On a side note, while node level locks may be the most granular, some update
> operations may require locking multiple nodes. For instance, if you replace
> an element that has attributes and children, a lock of the element may imply
> a lock of its attributes and descendants as well.