Status: IN
Serializable snapshot isolation is achieved by composing two complementary invariant layers: MVCC provides visibility correctness (append-only versions, own-writes guarantee, symmetric deletion visibility) while SSI adds serializability enforcement (read-only optimization, committed-only snapshots, write-delete mutual exclusion).
MVCC handles what a transaction can see while SSI handles what it can do — neither is sufficient alone
Depends on (SL): mvcc-three-layer-visibility-model, ssi-serializability-through-layered-invariants