What exactly does lazy do?

[abalter]

I just read in a large csv file. I used lazy=T. However, the size of the object I read the file into is the same size as the file itself.

Do I need to do something else to read the table in lazily?

If I am actually able to read in a file lazily, can I use dplyr verbs on it?

> library(tidyverse)
> df = read_csv('mem_detail.csv', lazy=T)
Rows: 61923459 Columns: 28
── Column specification ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
> object.size(df)
13048425864 bytes

-rw------- 1 balter  chse    12G Mar 12 19:05 mem_detail.csv

[hadley]

Duplicate of #1499