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Understand SQL: DELETE vs TRUNCATE, VIEW vs TABLE, CROSS JOIN

AmazonData Scientist · Technical Screen
MediumData ScientistTechnical ScreenData Manipulation (SQL/Python)

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This question evaluates a candidate's understanding of core SQL concepts and data-manipulation competencies, covering the behavior of data-deletion operations, distinctions between logical and physical data structures, and join semantics.

employees

+----+--------+---------+ | id | name | dept_id | +----+--------+---------+ | 1 | Alice | 10 | | 2 | Bob | 20 | | 3 | Carol | 10 | | 4 | Dave | 30 | +----+--------+---------+

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departments

+---------+-------------+ | dept_id | dept_name | +---------+-------------+ | 10 | Sales | | 20 | Marketing | | 30 | Engineering | +---------+-------------+

Scenario

Amazon BIE interview: assessing SQL fundamentals and understanding of relational concepts.

Question

Compare DELETE and TRUNCATE; when would you use each?

Contrast a VIEW with a physical TABLE; what are pros/cons?

What does a CROSS JOIN do, and in what real-world scenario would you apply it?

Hints

Discuss transactional logging, constraints, persistence, and Cartesian product size considerations.