I have a 40gb csv file with over 60 million rows for data analysis. Each row has a unique identifier (some numbers). For example, the first row's unique identifier will repeat approximately 150,000 rows later.
I would like to have a method to run through the entire file, and extract rows with the same identifier and write them into new csv files. Is there a good, automated way to do that? Please note that the file is very large and excel has problems opening it.