Window with orderBy¶

It is tricky!!!

If you provide ORDER BY clause then the default frame is RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW:

https://stackoverflow.com/questions/52273186/pyspark-spark-window-function-first-last-issue

1. Avoid using last and use first with descending order by instead. This gives less surprisings.

2. Do NOT use order by if not necessary. It introduces unnecessary ...