1. What is Window function ? Senior A. SUM(...) OVER (ORDER BY ...) that accumulates values across ordered rows B. divides rows into groups within which a window function operates C. a function computing across a set of rows related to the current row without collapsing them D. RANK leaves gaps in numbering after ties; DENSE_RANK does not
2. Which term means: "a function computing across a set of rows related to the current row without collapsing them"? Senior A. Window function B. ROW_NUMBER C. Running total D. LAG / LEAD
3. Which statement is correct? Senior A. Window function — divides rows into groups within which a window function operates B. Window function — SUM(...) OVER (ORDER BY ...) that accumulates values across ordered rows C. Window function — a function computing across a set of rows related to the current row without collapsing them D. Window function — assigns a unique sequential number to rows within a partition
4. What is ROW_NUMBER ? Mid A. divides rows into groups within which a window function operates B. assigns a unique sequential number to rows within a partition C. a function computing across a set of rows related to the current row without collapsing them D. RANK leaves gaps in numbering after ties; DENSE_RANK does not
5. Which term means: "assigns a unique sequential number to rows within a partition"? Mid A. LAG / LEAD B. RANK vs DENSE_RANK C. ROW_NUMBER D. PARTITION BY
6. Which statement is correct? Mid A. ROW_NUMBER — a function computing across a set of rows related to the current row without collapsing them B. ROW_NUMBER — RANK leaves gaps in numbering after ties; DENSE_RANK does not C. ROW_NUMBER — SUM(...) OVER (ORDER BY ...) that accumulates values across ordered rows D. ROW_NUMBER — assigns a unique sequential number to rows within a partition
7. What is RANK vs DENSE_RANK ? Senior A. assigns a unique sequential number to rows within a partition B. divides rows into groups within which a window function operates C. a function computing across a set of rows related to the current row without collapsing them D. RANK leaves gaps in numbering after ties; DENSE_RANK does not
8. Which term means: "RANK leaves gaps in numbering after ties; DENSE_RANK does not"? Senior A. Running total B. ROW_NUMBER C. RANK vs DENSE_RANK D. PARTITION BY
9. Which statement is correct? Senior A. RANK vs DENSE_RANK — access a value from a previous or following row within the partition B. RANK vs DENSE_RANK — divides rows into groups within which a window function operates C. RANK vs DENSE_RANK — RANK leaves gaps in numbering after ties; DENSE_RANK does not D. RANK vs DENSE_RANK — SUM(...) OVER (ORDER BY ...) that accumulates values across ordered rows
10. What is PARTITION BY ? Senior A. access a value from a previous or following row within the partition B. a function computing across a set of rows related to the current row without collapsing them C. divides rows into groups within which a window function operates D. assigns a unique sequential number to rows within a partition
11. Which term means: "divides rows into groups within which a window function operates"? Senior A. LAG / LEAD B. PARTITION BY C. Running total D. RANK vs DENSE_RANK
12. Which statement is correct? Senior A. PARTITION BY — a function computing across a set of rows related to the current row without collapsing them B. PARTITION BY — assigns a unique sequential number to rows within a partition C. PARTITION BY — RANK leaves gaps in numbering after ties; DENSE_RANK does not D. PARTITION BY — divides rows into groups within which a window function operates
13. What is LAG / LEAD ? Senior A. a function computing across a set of rows related to the current row without collapsing them B. access a value from a previous or following row within the partition C. divides rows into groups within which a window function operates D. RANK leaves gaps in numbering after ties; DENSE_RANK does not
14. Which term means: "access a value from a previous or following row within the partition"? Senior A. LAG / LEAD B. RANK vs DENSE_RANK C. ROW_NUMBER D. PARTITION BY
15. Which statement is correct? Senior A. LAG / LEAD — SUM(...) OVER (ORDER BY ...) that accumulates values across ordered rows B. LAG / LEAD — assigns a unique sequential number to rows within a partition C. LAG / LEAD — access a value from a previous or following row within the partition D. LAG / LEAD — divides rows into groups within which a window function operates
16. What is Running total ? Senior A. assigns a unique sequential number to rows within a partition B. access a value from a previous or following row within the partition C. a function computing across a set of rows related to the current row without collapsing them D. SUM(...) OVER (ORDER BY ...) that accumulates values across ordered rows
17. Which term means: "SUM(...) OVER (ORDER BY ...) that accumulates values across ordered rows"? Senior A. Running total B. RANK vs DENSE_RANK C. PARTITION BY D. ROW_NUMBER
18. Which statement is correct? Senior A. Running total — divides rows into groups within which a window function operates B. Running total — SUM(...) OVER (ORDER BY ...) that accumulates values across ordered rows C. Running total — access a value from a previous or following row within the partition D. Running total — assigns a unique sequential number to rows within a partition