Serach by unique_id Vs. username - which is faster?

Hello,

I would like to know what would be faster to searching/fetching data in database, using Username (unique) OR Unique_id (bubble native) ?

Or maybe it only depends on how may strings I have in the field I use for fetching ?

Do you have any experience with slow fetching using another field than Unique-id ?

Any advices ?

Cheers !!

What about trying both to see which works fast.
I think using constraints can improve the performance.

I am still learning, please share your experience here for others to find this post helpful.