@Girgias@ClubTeleMatique I can't believe this #php advice is still doing the rounds. It's 10 years old and mostly wrong, or at least pointless micro-optimisations.
Reduce database calls. Make sure you're getting the data you want and not just doing SELECT *. Make sure indexes are in place where they need to be. Don't bloat the call stack. Do some profiling, especially of actual, real-world usage.
Thanks for coming to my TED talk.
Xenograg