Completed Mock-SQL-3

[DhruvParashar246]

No description provided.

[super30admin]

The student's solution demonstrates a good understanding of SQL concepts and window functions, but there are several areas for improvement:

1. Correctness:

• For Market Analysis II: The solution correctly identifies the second item sold by each seller and checks if it matches their favorite brand. However, it doesn't handle cases where a seller has less than 2 orders (which is correctly addressed with the LEFT JOIN).
• For Tournament Winners: The solution correctly calculates total scores and selects the top player per group. The tie-breaker (player_id) is appropriately implemented.

2. Time Complexity:

• Both solutions use window functions (RANK() and ROW_NUMBER()) which typically have O(n log n) complexity due to sorting.
• The JOIN operations add to the complexity, but this is standard for SQL queries.

3. Space Complexity:

• The CTEs create temporary result sets, but this is necessary for the logic and standard practice in SQL.

4. Code Quality:

• Strengths:
  • Clear use of CTEs to break down complex logic
  • Proper use of window functions
  • Consistent formatting
• Areas for Improvement:
  • Column aliases should avoid using single quotes (use double quotes or no quotes for standard identifiers)
  • The CTE names could be more descriptive (e.g., "SecondItems" instead of "ACTE")
  • The CASE statement in Market Analysis II could be simplified

5. Efficiency:

• Both solutions could potentially benefit from proper indexing on join columns and filter conditions.
• For Tournament Winners, consider if a simpler approach without UNION ALL might be possible.