Recall & Review
beginner
What is a Slowly Changing Dimension (SCD) Type 2?
SCD Type 2 is a method to track historical changes in data by creating new records for each change instead of overwriting old data. This keeps full history of changes.
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beginner
Why use SCD Type 2 in data warehousing?
To keep a full history of changes in dimension data, allowing analysis of data as it was at any point in time.
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intermediate
In SCD Type 2, what columns are commonly added to track changes?
Columns like 'effective_date', 'end_date', and 'current_flag' are added to mark when a record is valid and if it is the current version.
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intermediate
How does dbt help implement SCD Type 2?
dbt automates SCD Type 2 using snapshots to detect changes and create new records.
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beginner
What is the difference between SCD Type 1 and Type 2?
Type 1 overwrites old data with new data (no history), while Type 2 keeps old data by adding new records for changes (full history).
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What does SCD Type 2 do when a dimension attribute changes?
✗ Incorrect
SCD Type 2 creates a new record to keep the history of changes.
Which column is NOT typically used in SCD Type 2?
✗ Incorrect
Password is unrelated to tracking changes in SCD Type 2.
In dbt, what feature helps implement SCD Type 2?
✗ Incorrect
Snapshots are designed to capture historical data changes, implementing SCD Type 2.
What is the main benefit of SCD Type 2?
✗ Incorrect
SCD Type 2 keeps full history by storing multiple versions of records.
Which SCD type overwrites old data without keeping history?
✗ Incorrect
Type 1 overwrites old data, losing history.
Explain how Slowly Changing Dimension Type 2 works and why it is useful.
Think about how you keep old versions of a document instead of deleting them.
You got /4 concepts.
Describe how you would implement SCD Type 2 using dbt.
Consider how dbt can add new rows instead of replacing existing ones.
You got /4 concepts.