Data is layered: four models stacked
Data is layered: four models stacked
L1 App objects
people, orders, sensors, as code
L2 Storage model
JSON, tables, or graph: this chapter
L3 Storage engine
bytes on disk and memory (chapter 4)
L4 Hardware
currents, light, magnetism
abstracts
encodes
embodies
each layer hides the one below, so many teams can collaborate