Replace white spaces in BIG text files

Hi.
I regularly need to transform and then upload to database some text files sent by some clients.
One of those files has multiple white spaces for each line which are redundant and make the file much bigger than needed.

Note that the file is around 19 GB, so I wonder if there's a way for me to replace all those white spaces using PDI - to be on the safe side, I would replace 3 spaces with 1 (obviously this should be done recursively).

I am open to suggestion, even to use a different program (as long as a CLI is available) to cut those spaces.

Note that I work in Windows and I cannot really write any kind of code :-(

Thanks.
Michele