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Exam Certified Data Engineer Professional All Questions

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Exam Certified Data Engineer Professional topic 1 question 147 discussion

Actual exam question from Databricks's Certified Data Engineer Professional
Question #: 147
Topic #: 1
[All Certified Data Engineer Professional Questions]

A junior data engineer seeks to leverage Delta Lake's Change Data Feed functionality to create a Type 1 table representing all of the values that have ever been valid for all rows in a bronze table created with the property delta.enableChangeDataFeed = true. They plan to execute the following code as a daily job:



Which statement describes the execution and results of running the above query multiple times?

  • A. Each time the job is executed, newly updated records will be merged into the target table, overwriting previous values with the same primary keys.
  • B. Each time the job is executed, the entire available history of inserted or updated records will be appended to the target table, resulting in many duplicate entries.
  • C. Each time the job is executed, only those records that have been inserted or updated since the last execution will be appended to the target table, giving the desired result.
  • D. Each time the job is executed, the differences between the original and current versions are calculated; this may result in duplicate entries for some records.
Show Suggested Answer Hide Answer
Suggested Answer: B 🗳️
by Adrifersilva at Sept. 21, 2024, 1:53 p.m.

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benni_ale
2 weeks, 4 days ago
Selected Answer: B
B seems ok
upvoted 1 times
...
m79590530
1 month ago
Selected Answer: B
Since the code is using version 0 for the CDF-enabled table every time it is executed all the historical changes being insert of update for the table will be 'append'-ed to the target table since this is the write command option provided.
upvoted 1 times
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Adrifersilva
2 months ago
B. This bad effect (many duplicates) happens because the code reads from the starting version 0, appending all changes since the beginning.
upvoted 2 times
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