[Mulgara-general] Loading from files and transactions

[Alex Hall]

I'm working on an application that will use Mulgara for two types of 
operations on RDF graphs.  First, we will have relatively small updates 
(inserts or deletes involving a handful of statements on existing 
graphs) that need to execute as an atomic operation.  Second, we will 
have loads of potentially very large RDF files into new graphs.  There 
will be multiple web-based clients which can initiate either type of 
operation, although the first will be much more common than the second.

Given these factors, the single write transaction constraint imposed by 
Mulgara is going to be a big challenge for us.  I don't mind being 
limited to a single small update at a time since these generally execute 
in a matter of seconds.  However, loading RDF from a file into a graph 
can take minutes or hours, during which time all other write operations 
will be locked out.  It would be nice if we could stage our loads so 
that updates could continue to execute at the same time.  However, the 
workarounds I've come up with to support such a scenario seem so kludgy 
that I'm almost embarrassed to have thought of them.

Obviously, what I'd really like is support for multiple write 
transactions at once.  In the meantime, I'm wondering if anybody else 
has encountered a similar situation, or can suggest an alternative 
approach to this problem.

Regards,
Alex