Re: Locking

2024-03-17 Thread Laurenz Albe
On Sun, 2024-03-17 at 15:11 +1000, Anthony Berglas wrote: > I would write something iff there is interest in posting it. I cannot promise that the patch would be accepted; I personally think that briefly mentioning transaction anomalies and isolation levels would be ok. > Probably an overview in

Re: Locking

2024-03-16 Thread Laurenz Albe
On Sat, 2024-03-16 at 10:52 +1000, Anthony Berglas wrote: > The code is wrong by any normal definition.  We lose one of the updates. > It is a very common error.  It is a very common way to write code, > especially if using an ORM, which is very common. > > [example of a lost update] > > The probl

Re: Locking

2024-03-15 Thread Laurenz Albe
On Thu, 2024-03-14 at 00:16 +, PG Doc comments form wrote: > There really needs to be an explicit warning that the following is invalid > in normal read committed mode:- > > select foo into f from bar where id=1; > f = f + 123; > update bar set foo = f where id =1; > commit; > > This is a ver