Consider a table ‘transactions’ with a composite index on (status, created_at). You execute the following query: SELECT id, amount FROM transactions WHERE status = ‘COMPLETED’ AND created_at > ‘2023-01-01’ OR status = ‘PENDING’; Given the operator precedence in SQL, how will the database engine likely process this filter, and what is the impact on index utilization? SQL Data AnalystHard Try Now
What does the SQL temporal table (system-versioned table) feature provide? SQL FundamentalsHard Try Now
What does the following demonstrate about the EXISTS vs IN performance trade-off? — Query A: WHERE id IN (SELECT customer_id FROM orders WHERE total > 1000) — Query B: WHERE EXISTS (SELECT 1 FROM orders o WHERE o.customer_id = c.id AND o.total > 1000) SQL FundamentalsHard Try Now
What is the consequence of having too many autoloaded or frequently-updated rows in the same database page? SQL FundamentalsHard Try Now
What does the following query return and what performance concern does it raise? SELECT * FROM orders WHERE YEAR(order_date) = 2023 SQL FundamentalsHard Try Now
What does the following query demonstrate about NULL handling in aggregates? SELECT AVG(bonus) FROM employees SQL FundamentalsHard Try Now
What does the SQL standard LATERAL join (or CROSS APPLY in SQL Server) enable? SQL FundamentalsHard Try Now
What does the following query do? SELECT id, salary, ROW_NUMBER() OVER (PARTITION BY dept ORDER BY salary DESC) AS rn FROM employees QUALIFY rn = 1 SQL FundamentalsHard Try Now
What does the GENERATED ALWAYS AS (expression) STORED column definition do? SQL FundamentalsHard Try Now
What does the following pattern detect? SELECT a.id FROM tableA a WHERE NOT EXISTS (SELECT 1 FROM tableB b WHERE b.a_id = a.id) SQL FundamentalsHard Try Now
