alt Hacker NewsThat’s not true for Postgres however: due to its usage of a shared memory pool, whenever a subprocess is terminated unexpectedly, Postgres will kill all other processes and enter recovery mode, replaying the WAL, during which time it will not accept connection requests.
It does this because it can’t possibly know whether the dying process did bad things to the shared memory pool.
You are correct! TIL, and thank you. Connection processes get a SIGQUIT, shared buffers cleared, and WAL replayed, but postmaster stays alive. It's effectively an online restart.