concept · concepts/Lands vs Lives.md

Lands vs Lives

status: active · created 2026-06-26 · 1 source · #data-engineering #data-modeling #lineage #craft

Two different questions about the same data: where it lands (the one physical base table the bytes are actually written to) versus where it lives (the layer that gives them business meaning). In a view-only medallion these can be different objects, and confusing them sends you to the wrong place.

Explanation

In a view-only medallion, the upper tiers are views, not materializations — so there is exactly one physical base table in the chain. The source (Working Heuristics — Data, Matching, Product, Org, Tooling) names the distinction sharply:

  • Where data lands = that single physical base table. This is where bytes are stored, where load failures and freshness problems originate, where governance and retention actually bite.
  • Where data lives = the view layer that does the modeling. This is where the data acquires its business shape and meaning, and what consumers read.

Why it matters

The distinction is a debugging and ownership compass. A correctness or freshness problem traces back to where data lands; a meaning or shaping problem lives in the modeling layer. Conflate them and you waste time editing a view when the bug is in the base table, or auditing a base table when the logic error is in a view. It also tells you where to point a Data Contract (at the boundary the physical table exposes) and what the real System of Record is (the thing data lands in, not necessarily the view everyone queries).

Connections

  • Medallion Architecture — the lands-vs-lives gap only opens up in a view-only (non-materialized) medallion; this is its headline reading.
  • Pipeline Legibility — knowing where data lands vs lives is one half of reading a pipeline honestly; naming it for the flow direction is the other.
  • System of Record — the SOT is anchored at where data lands, not at the convenient view where it lives.

Sources

The wiki is the source. This door reads it at build time and never writes to it.