A short recap after reading kinda oldish Processing large CSV files with Ruby.

There are multiple ways of achieving the same result, but with different resources usages. If you want to iterate over CSV file in Ruby, CSV#foreach is your friend.

CSV.foreach('data.csv', headers: true).with_index do |row, i|
  puts "Row #{ i }: #{ row.join(',') }"
end

Pros: no memory overhead 😺
Cons: more I/O operations as file’s lines are read one-by-one 😿