Scalar Functions — Window

Window functions compute values relative to neighboring rows within a result set. All four dialects support the full set of KQL window functions — they map directly to standard SQL window function syntax using OVER () clauses.

Legend: ✅ Supported · ⚠️ Approximated · ❌ Not Supported · 🔄 Rewritten

Function	SQLite	MySQL	ClickHouse	PostgreSQL	Notes
row_number()	✅	✅	✅	✅	row_number() OVER ()
prev()	✅	✅	✅	✅	LAG() OVER ()
next()	✅	✅	✅	✅	LEAD() OVER ()
row_cumsum()	✅	✅	✅	✅	SUM() OVER (ROWS UNBOUNDED PRECEDING)
row_rank()	✅	✅	✅	✅	DENSE_RANK() OVER (ORDER BY col)