On Wed, 2021-09-08 at 08:23 +0000, PG Doc comments form wrote: > The following documentation comment has been logged on the website: > > Page: https://www.postgresql.org/docs/13/explicit-locking.html > Description: > > The docs mention "For example, a common use of advisory locks is to emulate > pessimistic locking strategies typical of so-called “flat file” data > management systems" which is exactly what I wanted to use to port some code > from using SQLite to using PostgreSQL. (The code in question requires > serializable transactions and cannot not handle retries.) > > The next paragraph explains session and transaction level advisory locks and > mentions that transaction level locks are "often more convenient than the > session-level behavior". This seemed to be true for this use case, so I > chose to use them. > > Later I discovered that obtaining a transaction level lock as first > statement _within_ a transaction is not sufficient to emulate global > pessimistic locking and can occasionally still result in serialization > failures.
I don't see how that is related to session-level vs. transaction level locks. erhaps you can explain your case in some more detail. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com
