I'm sorry, but you're wrong... In Postgresql, the default ISOLATION LEVEL is "READ COMMITTED", which by standard, allows "NON-REPEATABLE READ" phenomena. When

I'm sorry, but you're wrong... In Postgresql, the default ISOLATION LEVEL is "READ COMMITTED", which by standard, allows "NON-REPEATABLE READ" phenomena. When Transaction on the LEFT is COMMITTED (adding 100 to balance), the Transaction on the RIGHT will add 400 to a balance of 1100, and not to a balance of 1000 (reading NON-REPEATED value). You can do better than leaving this kind of comment that does not contribute in anything. Have good weekend.