A new triplestore to support core relationships
management in the core Fedora repository will be
developed for the following reasons:
- make core repository not dependent on kowari
- due to kowari instability issues and high memory
requirements, we must ensure that the core repository
is not vulnerable to these things
- basic relationship management is something we can
achieve with a simpler triplestore.
- basic relationship management must be contained
within the contect of a Fedora API-M transaction.
Right now, the kowari solution entails Fedora writing
triples to a buffer that is outside the context of the
Fedora API-M transaction, thus it cannot be guaranteed
that such triples have successfully been written to the
triplestore from the buffer by the time the Fedora
API-M transaction is completed.
For these and other reason, a new triplestore is being
developed using relational database technology. The
design of this triplestore is based on mapped triple
tables (thus MTP). It will hold all the same
information currently in the Resource Index model.
Initially, it will support SPO queries.
This will be an alternative configuration for the
Resource Index in the core Fedora. It will still be
possible to configure kowari as the triplestore.
At the same time, we are moving forward with designs to
have a Resource Index service that can be outside the
core Fedora repository. The idea is to have simpler
and more tranasction-savvy relationship management at
the core of Fedora, then be able to replicate the
managed triples from the core to triplestore outside
the repository (the Resource Index service) via
messaging. The motivation here is to make the external
service be where more semantic web activities happen
(outside of the core repository). The base information
from the repository can be enriched in the service (add
information from other ontologies, add other kinds of
relationships, whatever.) Then, full blown
capabilities such as inferencing, can be done via the
service without bogging down the core repository.