Common issues with CSV parsing with Ruby and solutions to them

Problem: you are parsing a large CSV file, and it takes a lot of time to process the whole file, or your server is running out of memory when the process is in the middle.Solution: when processing CSV files with Ruby, always use the CSV.foreach method instead of CSV.read or CSV.parse. The reason is simple: while read and parse methods load the whole file into the memory and then process it, the foreach method process the file line by line without loading all contents at once. By iterating the file line by line, you won’t use much memory, and you would get access to the rows immediately.Imagine that you are looking for one row in a file that consists of millions of rows. With CSV.foreach, you won’t load all rows at once and stop processing as soon as you find the row you are looking for.