PostgreSQL lightweight locks, or LWLocks, control memory access. PostgreSQL uses multi-process architecture and should allow only consistent reads and writes to shared memory structures. LWLocks have two levels of locking: shared and exclusive. It’s also possible to release all acquired LWLocks to simplify clean up. Other databases often call primitives similar to LWLocks latches. Because [&]

https://www.percona.com/blog/2018/10/30/postgresql-locking-part-3-lightweight-locks/