SQL Window Functions Cheat Sheet PDF, Data Engineer Interview Prep, SQL Quick Reference Printable

Stop blanking on window functions mid-interview.

This 3-page cheat sheet distills the SQL window functions that show up in nearly every data engineering interview into one tight, scannable reference: what each function does, how frames work, the gotchas that trip people up, and 12 copy-ready query patterns to memorize.

WHAT'S INSIDE
- 12-function quick reference: ROW_NUMBER, RANK, DENSE_RANK, NTILE, LAG/LEAD, FIRST_VALUE, LAST_VALUE, NTH_VALUE, aggregates as windows, CUME_DIST, PERCENT_RANK
- Anatomy of the OVER clause: PARTITION BY, ORDER BY, frame syntax
- Frame clauses explained: ROWS vs RANGE, UNBOUNDED PRECEDING/FOLLOWING, the default-frame trap behind LAST_VALUE surprises
- 6 gotchas: why window functions can't go in WHERE, logical evaluation order, NULL edges on LAG/LEAD, deterministic ordering with ties
- 12 patterns to memorize: top-N per group, running totals, 7-day moving average, month-over-month growth, dedupe (keep latest), days-since-previous, share of total, quartiles, trend vs previous row, and more

WHAT YOU GET
- 8 PDFs: 2 designs (code-editor minimal + neutral modern) x US Letter & A4 x printable & fillable versions
- Fillable PDFs work in any PDF reader - type straight into the notes panel
- Instant download; print at home or use on a tablet

All SQL verified against Postgres semantics.

AI USE DISCLOSURE
This cheat sheet's content and layouts were drafted with the help of AI tools, then reviewed, corrected, and refined by the seller (a working data engineer) before release - including an independent SQL correctness review. What you're buying is the reviewed, finished product.

PLEASE NOTE
- This is a digital download; no physical item will be shipped.
- Due to the nature of digital products, refunds aren't available - but if a file is ever corrupted or incomplete, message me and I'll make it right.