Append-only ledger
INSERT
v1
valid_to: t2
risk_tolerance: low
t1 · trace_id: a91f
v2
valid_to: t3
risk_tolerance: medium
t2 · trace_id: c30d
v3
valid_to: null
risk_tolerance: high
t3 · trace_id: f7b2
audit: full history queryable at any T
Destructive overwrite
UPDATE
row (mutable)
v3
risk_tolerance: high
v1 risk_tolerance: low / gone
v2 risk_tolerance: medium / gone
audit: prior state destroyed, cannot time-travel