Which slowly changing dimension (SCD) type overwrites the old attribute value without preserving history? SQL Data AnalystHard Try Now
What does PERCENT_RANK() return for the first row in a partition ordered by salary ASC? SQL Data AnalystHard Try Now
What does EXPLAIN (or EXPLAIN ANALYZE in PostgreSQL) show about a query? SQL Data AnalystHard Try Now
Which SQL feature allows you to pivot rows into columns dynamically without hardcoding column names? SQL Data AnalystHard Try Now
What is the result of a CROSS JOIN between a table of 5 rows and a table of 8 rows? SQL Data AnalystHard Try Now
An analyst writes: SELECT dept, AVG(salary) FROM employees GROUP BY dept HAVING AVG(salary) > 70000. What does HAVING filter on here? SQL Data AnalystHard Try Now
Which isolation level prevents dirty reads but still allows non-repeatable reads? SQL Data AnalystMedium Try Now
You need the moving average of the last 3 rows including the current row. Which frame clause achieves this? SQL Data AnalystHard Try Now
