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Databricks Exam Databricks Certified Data Engineer Professional Topic 1 Question 19 Discussion

Actual exam question for Databricks's Databricks Certified Data Engineer Professional exam
Question #: 19
Topic #: 1
[All Databricks Certified Data Engineer Professional Questions]

The downstream consumers of a Delta Lake table have been complaining about data quality issues impacting performance in their applications. Specifically, they have complained that invalid latitude and longitude values in the activity_details table have been breaking their ability to use other geolocation processes.

A junior engineer has written the following code to add CHECK constraints to the Delta Lake table:

A senior engineer has confirmed the above logic is correct and the valid ranges for latitude and longitude are provided, but the code fails when executed.

Which statement explains the cause of this failure?

Show Suggested Answer Hide Answer
Suggested Answer: B

A unit test is designed to verify the correctness of a small, isolated piece of code, typically a single function. Testing a mathematical function that calculates the area under a curve is an example of a unit test because it is testing a specific, individual function to ensure it operates as expected.


Software Testing Fundamentals: Unit Testing

Contribute your Thoughts:

Dean
2 months ago
Well, at least the senior engineer caught it before it went to production and caused a massive outage. Gotta love those 'I told you so' moments. C is the way to go.
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Yvette
18 days ago
Definitely, it's better to catch these issues early on.
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Jenise
24 days ago
Definitely, it's better to catch these issues early on.
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Blair
1 months ago
Yeah, it's important to validate existing data before adding constraints.
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Aleta
2 months ago
C) The activity details table already contains records that violate the constraints; all existing data must pass CHECK constraints in order to add them to an existing table.
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Marguerita
2 months ago
Yeah, it's important to validate existing data before adding constraints.
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Aileen
2 months ago
C) The activity details table already contains records that violate the constraints; all existing data must pass CHECK constraints in order to add them to an existing table.
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Jerrod
2 months ago
Haha, I bet the junior engineer is feeling pretty embarrassed right now. Should have known better than to try and sneak that in without checking the existing data! C is the right choice.
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Elza
2 months ago
I agree, C is the correct answer. It's important to make sure existing data meets the constraints before adding them, otherwise the operation will fail. Learned that the hard way on a previous project.
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Felicidad
25 days ago
Lesson learned: always check existing data before applying constraints.
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Sharmaine
1 months ago
Definitely, it can save a lot of time and prevent failures in the long run.
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Mitsue
1 months ago
I've encountered a similar issue before. It's crucial to validate existing data before adding constraints.
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Ettie
2 months ago
C) The activity details table already contains records that violate the constraints; all existing data must pass CHECK constraints in order to add them to an existing table.
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Sharika
2 months ago
The answer is C. The table already contains records, so the CHECK constraints can't be added without validating the existing data first. Seems like a common gotcha for Delta Lake tables.
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Vincent
3 months ago
But what about enabling schema evolution to alter the table and add the constraint? Could that be a solution?
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Grover
3 months ago
I agree with Bernadine. All existing data must pass CHECK constraints in order to add them to an existing table.
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Bernadine
3 months ago
I think the cause of the failure is because the table already contains records that violate the constraints.
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