Project Every Record Counts: Data Engineering for Backend Engineers
Part 6: "SQL You Will Actually Use" — Analytical SQL for Data Engineers
Rohan wants to loop over events in Java; Ingrid hands over a SQL workbook instead. Window functions, QUALIFY, gaps and islands, sessions, PIVOT, CUBE, HyperLogLog, MERGE, high-water marks and query plans in DuckDB and Trino find the 2,455 re-sent UK baskets behind £118,076.98 and explain why conversion reads 6.21% or 5.31%.