DBT Data Modeling & Transformation 2

Question 1

Which macro filters rows in an incremental model so only new data is processed on subsequent runs?

Accepted Answer

Answer

is_incremental() returns true when the model already exists, is configured incremental, and no full refresh is requested.

Question 2

In an incremental model's SQL, which relation does {{ this }} refer to?

Accepted Answer

The currently building model's existing table in the warehouse

Answer

{{ this }} resolves to the already-built relation of the model, used to find the max timestamp.

Question 3

What does running `dbt run --full-refresh` do to an incremental model?

Accepted Answer

Drops and rebuilds it from scratch

Answer

Full refresh rebuilds incremental models as if they did not exist, ignoring is_incremental() logic.

Question 4

Which config tells an incremental model how to match existing rows for updating?

Accepted Answer

unique_key

Answer

unique_key identifies rows to update or replace, depending on the incremental strategy.

Question 5

Which materialization creates no object in the warehouse and inlines the model as a CTE in downstream models?

Accepted Answer

ephemeral

Answer

Ephemeral models are interpolated as CTEs into dependent models and are not built.

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