Understand SQL: DELETE vs TRUNCATE, VIEW vs TABLE, CROSS JOIN
Company: Amazon
Role: Data Scientist
Category: Data Manipulation (SQL/Python)
Difficulty: Medium
Interview Round: Technical Screen
employees
+----+--------+---------+
| id | name | dept_id |
+----+--------+---------+
| 1 | Alice | 10 |
| 2 | Bob | 20 |
| 3 | Carol | 10 |
| 4 | Dave | 30 |
+----+--------+---------+
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.
Quick Answer: 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.