> If you were right, there would be tons of example code retrying database transactions. In popular webframeworks, in Wordpress, Joomla, etc. And it is just no

> If you were right, there would be tons of example code retrying database transactions. In popular webframeworks, in Wordpress, Joomla, etc. And it is just not there. This is one thing that seemed really strange to me when I was learning this -- all the guides talk about (say) parameterized queries, and people mention transactions, but nobody says what to do if there's a conflict. I basically had to work it out myself. I'm not a DB person, but I am an Operating Systems person, and I am absolutely confident that there is no clever system that can work around the scenario I described above without 1) restarting one of the transactions, 2) failing one of the transactions, or 3) putting the DB in an inconsistent state. All I can think of is that in the vast majority of cases, people are getting lucky: It just happens that people almost never modify the same data at the same time; and if one out of every million operations fail, but do so in a safe manner (not corrupting data), people just chalk it up to your website being quirky or something. EDIT OK, I followed the link of the sibling, and read up about the SQL standard's various levels of transaction isolation. I'm not sure what my example would do in the "Read Committed" case (apparently the default for Posgresql); and I can't imagine programming anything important when I didn't actually know how the default consistency guarantee would behave.