Before heading home for the holidays, I had a large data set (1.6 GB with over 1.25 million rows) with columns of text and integers ripped out of the company (Kwelia) Database and put into a .csv file since I was going to be offline a lot over the break. I tried opening the csv file in the usual way:
all <- read.csv("file.csv")
However it never finished even after letting it go all night. I also tried reading it into a SQLlite database first and reading it out of that, but the file was so messy it kept coming back with errors. I finally got it read in to R by using the ff package and the following code:
library("ff") x<- read.csv.ffdf(file="file.csv", header=TRUE, VERBOSE=TRUE, first.rows=10000, next.rows=50000, colClasses=NA)
Because the file was so messy, I had to turn off column classes (colClasses=NA) to have the read ignore giving each column a class on the first 10,000. After reading the first 10,000 rows, the script then reads in chunks of 50,000 so as to not completely overload the ram in my laptop. I also turned Verbose because it would drive me nuts to not be able to follow the progress.