Lesbos Transactions? No....
lightweight transactions such as Paxos
Kudos for mentioning PAXOS but AFAIK PAXOS is just the general case of the 2-phase commit protocol (n-phase commit protocol?), the latter hidden under the "Distributed Transactions" designator. So not particularly lightweight .
In truth, I haven't understood PAXOS as far as I would like, Leslie Lamport's original paper was way confusing the last time I read it. I need to start again...
Centerum Censo, people should read: A Critique of ANSI SQL Isolation Levels. Transactions - An underrated area of interesting stuff.