Hi,
The prepare() call you are using is the right way to go. This is the
closest to incremental processing the engine supports - the reset() and
rebind() calls basically start over from scratch.
Triggering it on every update will be inefficient but the best you can
do in most general case to achieve eager eval. Depending on your
application you may be able to batch these (with count and/or time
threshold) or trigger after some application specific batch of updates.
Dave
On 06/02/2020 16:20, Nouwt, B. (Barry) wrote:
Hi all,
We are using Apache Jena in our project and noticed that the
GenericRuleReasoner InfGraph is lazy. Namely, after a SPARQL INSERT query on
the dataset, the matching rules do not get applied immediately. Only after
performing a SPARQL SELECT query on the dataset, the matching rules will be
applied.
We would like to disable this lazy behavior, because it conflicts with our use
case, but we are not sure how to do it properly (and less brute force).
Currently, we attach a GraphListener to that graph in which we force a
prepare() each time one of GraphListener's update methods is called, but this
has some side effects (among others the reapplying of rules that were already
applied) that we would like to prevent. I assume there is a less brute force
manner to kick the reasoner into action (similar to what a SPARQL SELECT query
achieves), but I'm not sure what this is. If I look at the source code of Jena
I see several candidates, like the BaseInfGraph.rebind() and
BaseInfGraph.reset() method, are those better options?
Does anyone has an idea how to achieve non-laziness of the InfGraph some other
way?
Thanks in advance!
Barry
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