OSLC Link Discovery Management - optional restriction for predicates

[MartinUlrich]

For the Link Discovery Service restriction based on the Link Predicates is considered.
Here the question shall be discussed, if the Link Predicate/s are mandatory or optional.

In todays IBM LDX implementation the link predicate is mandatory, as the client in any case is explicitly interested in defined link predicate/s.

Still the use case is likely, that a client is interested in any links pointing to the objects e.g. visualized on the screen.

Therefore the predicate shall be optional.

In case of overload a server can respond with e.g. bad request

[DavidJohnHoney]

This has potential performance and implementation consequences for implementations. Finding all links of any type could be very inefficient and lead to scalability and performance issues. I recommend that the first version of the LDM specification specifies the link types are mandatory. This matches the current implementation in IBM Rational ELM.