Project Development Flashcards

A source system overwrites customer rows in place and you need to track historical changes as type 2 slowly changing dimensions. Which dbt resource do you build?

Answer: A snapshot

Snapshots record row changes over time with dbt_valid_from and dbt_valid_to columns.

Your source table lacks a reliable updated_at column. Which snapshot strategy should you use?

Answer: check strategy with check_cols

The check strategy compares listed columns to detect changes when no trustworthy timestamp exists.

You want to grant SELECT on each model right after it is built. Which config is designed to run SQL after a model materializes?

Answer: post-hook

post-hook executes SQL immediately after the model is built (the grants config is also an option).

Which statement about macros in dbt is correct?

Answer: Macros are reusable Jinja functions defined with {% macro %} in .sql files, typically in macros/

Macros are Jinja blocks defined in .sql files that can be called from models, other macros, and hooks.

On an incremental model using the merge strategy, which config prevents duplicate records by updating existing rows?

Answer: unique_key

unique_key tells dbt which column(s) identify a row so matching rows are updated rather than inserted.

Which command selects only models whose definition changed compared to a production manifest?

Answer: dbt run --select state:modified --state path/to/prod_artifacts

The state:modified selector compares the current project to a manifest supplied via --state.

In a CI job you build only modified models but want unbuilt upstream refs to resolve to production objects. Which flag enables this?

Answer: --defer

--defer with --state resolves refs to non-selected, unbuilt nodes using the production manifest.