Minified vs. pretty XML

I have a text field in a PostgreSQL Database in which XML data is stored. Now I was wondering if it makes a difference to store the XML in minified or in pretty version. According to http://bytesizematters.com the size of the text itself does differ: Now I'm wondering if that will reflect on database size and performance. Maybe PostgreSQL is already optimizing text fields so much, that it actually doesn't matter. Unexpectedly, I didn't find anything on that topic on the internet. So if you have some links on that, I'd be very happy to read and learn more about DB optimization.