f0:string f1:int f2:int f3:double (all can be null)
bucket count: -1
row-tracking.enabled: true
data-evolution.enabled: false

Msgs:
snapshot-1
Add: "Lily", 2, 12, 2.1
Add: "Alice", 3, 13, 3.1
NoCompact

snapshot-2
Add: "Bob", 4, 14, 4.1
Add: "David", 5, 15, 5.1
NoCompact

snapshot-3-4
Compact
