> The major thrust of the theory section is that serializability is stronger than necessary to ensure consistency, but also that consistency needs a more rigorous definition.

Perhaps such consistency is best defined by specifying the permitted permutations of transaction order for each "observer":
- total ordering of conflicting write transactions
- causal ordering of non-conflicting write transactions
- fifo ordering of read transactions

> The 25 year fixation on serializability rather than consistency has lead to an unnecessarily constrained view of the range of database implementations.

Agree. If I were in the audience I would ask if the above set of constraints is the theoretical minimum still resulting in "consistency for each observer" and in identical state after quiescing ?

Paul