— PlayStation France (@PlayStationFR) October 28, 2015
One of the top-requested features on PlayStation Network is the ability to change your username, an issue to which Shuhei Yoshida responded in a questionnaire posed by invited players.
According to a translated video tweet by PlayStation France, Yoshida stated that Sony isn't even sure if it's possible at this point:
I wish I knew! We are aware lots of people are asking for the feature, and our engineers have been looking into what they can do.
As soon as we know, you know, we will let you know, but as of today, we don't even know if we can ever do it. Hopefully, we will be able to provide that feature in the future.
Sony has been struggling with honoring the request for PSN username changes for pretty much the last decade, and this response is merely evidence to the fact that PSN usernames are likely being used as the primary key in their database system.
It would require a lot of work to do change the system, even more now since the username is now tied to so many more features on PSN. It's not just a simple change to one table but numerous tables that need to be altered properly, and third-party apps will need to comply to the change for compatibility.
But it's still possible for them to essentially copy their current tables to another one which has an added field where we can change our displayed name while keeping your current PSN names unchanged, if that's the main hiccup. That's just one solution. Sony's engineers could also give each account an additional unique key of some kind to free the username as the primary key. Again, it's easier said than done, and it's better that they find the solution now or they'll be stuck with the system for many years to come.