Tableau Data Model: Logical Layer vs Physical Layer

Reading Time: 8 Mins | Level: Beginner to Advanced

1. The Two Layers of the Tableau Data Model

In modern Tableau (2020.2+), data modeling operates across two distinct layers:

1. The Logical Layer (The "Noodle" Relationships)

• The default canvas view.
• Tables are connected by flexible lines called Relationships (noodles).
• Smart Aggregation: Tableau retains each table at its native level of detail, preventing duplicate data multiplication issues (fan trap).

2. The Physical Layer (Joins & Unions)

• Double-clicking a logical table opens the physical layer.
• Here you configure traditional SQL Joins (Inner, Left, Right, Full Outer) or Unions.