Exam Certified Data Engineer Professional topic 1 question 113 discussion

Actual exam question from Databricks's Certified Data Engineer Professional

Question #: 113
Topic #: 1

[All Certified Data Engineer Professional Questions]

A Delta Lake table in the Lakehouse named customer_churn_params is used in churn prediction by the machine learning team. The table contains information about customers derived from a number of upstream sources. Currently, the data engineering team populates this table nightly by overwriting the table with the current valid values derived from upstream data sources.

Immediately after each update succeeds, the data engineering team would like to determine the difference between the new version and the previous version of the table.

Given the current implementation, which method can be used?

A. Execute a query to calculate the difference between the new version and the previous version using Delta Lake’s built-in versioning and lime travel functionality.
B. Parse the Delta Lake transaction log to identify all newly written data files.
C. Parse the Spark event logs to identify those rows that were updated, inserted, or deleted.
D. Execute DESCRIBE HISTORY customer_churn_params to obtain the full operation metrics for the update, including a log of all records that have been added or modified.
E. Use Delta Lake’s change data feed to identify those records that have been updated, inserted, or deleted.

Show Suggested Answer

Suggested Answer: A 🗳️

by MDWPartners at May 29, 2024, 5:53 p.m.

Comments

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KadELbied

2 months ago

Selected Answer: A

Suretly A

upvoted 1 times

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arekm

6 months ago

Selected Answer: A

D - see the discussion under Jugiboss comment.

upvoted 1 times

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Sriramiyer92

6 months, 3 weeks ago

Selected Answer: A

CDF is particularly useful in Incremental loads. In our case it is overwrite. Hence A.

upvoted 2 times

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Jugiboss

8 months, 2 weeks ago

Selected Answer: E

he best method to determine the difference between the new version and the previous version of the customer_churn_params table in Delta Lake is: E. Use Delta Lake’s change data feed to identify those records that have been updated, inserted, or deleted. This approach leverages Delta Lake's built-in functionality to track changes at the record level, providing a clear view of what has changed between versions.

upvoted 1 times

arekm

6 months ago

It is the best method so long as it is enabled, and we don't know. Moreover, CDF is designed for a small portion of the data being changed, not a full overwrite.

upvoted 1 times

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