How I Processed a File with 1 Billion Lines (And How You Can Too!)

1 File, 1 Billion Lines, 0 Meltdowns: A Go Success Story

Imagine you’re at an all-you-can-eat buffet… but instead of food, it’s a text file with one billion lines of data. Trying to read it all at once would be like trying to eat the entire buffet in one bite — impossible! Here’s how I tackled this massive “data buffet” using Go, and how you can too.

The Problem: A Text File Bigger Than Your Favorite Novel

Picture this:

• A typical novel has about 50,000 lines
• Your file has 1,000,000,000 lines — that’s 20,000 novels in one file!
• Opening it in Notepad would crash your computer (like trying to lift a car)

First Attempt: The “One Bite at a Time” Approach

// Like eating one french fry at a time
func slowCount() {
    file, _: = os.Open("hugefile.txt")
    scanner: = bufio.NewScanner(file)

    for scanner.Scan() {
        line: = scanner.Text()
            // Process line
    }
}

This works for small files, but for our billion-line buffet:

• It’s too slow (like eating with a toothpick)
• Uses only one CPU core (like…