The moment your data stops fitting: measure exactly why a 50 MB taxi file needs over 400 MB of RAM, learn to profile memory and dtypes, meet the data engineer's toolkit for taming it, and load only what you need — on the real NYC taxi dataset.
Welcome to When Data Outgrows Memory, the opening module of the course. Before you learn the techniques for handling large data, you should feel the problem precisely — in megabytes, on real data — so every fix that follows has a number attached to it.
You’ll start at the memory wall: load a month of real NYC taxi trips and watch a 50 MB file expand to over 400 MB of RAM, then understand exactly why. You’ll learn to profile a DataFrame’s memory column by column so you know where the weight is, survey the data engineer’s toolkit — the sequence of techniques this course teaches, from dtype tricks to chunking to distribution — and get your first concrete win by loading only the columns and rows you actually need. The module closes with a guided project that profiles the full dataset and turns the findings into a reduction plan you’ll execute later in the course.
Start with Lesson 1, and let the taxi data show you the wall.
Complete all 5 lessons to finish the When Data Outgrows Memory module.