2 ms·

Are you claiming that both inserts succeed even with a UNIQUE index in place, and they end up inserting duplicate values? That must be a bug if you're right.

• saltcured 3y ago
  I think they're saying that the unique index changes the locking strategy for the queries so they are effectively serialized and will not both read the same max value for existing rows.
  • dns_snek 3y ago
    That would make a lot of sense, thanks. I hope that's what the author meant.
    • hot_gril 3y ago
      Yeah, that's what I meant.