Re: Shared memory error

On Thu, Jun 4, 2020 at 6:18 AM Sonam Sharma <sonams1209(at)gmail(dot)com> wrote:
>>> 1) Postgres version : 11.2

FYI This is missing over a year's worth of bugfixes. That said, I
don't know of anything fixed that has this symptom.

>>> 4) Is this only with one query and if so what is it doing? : No , few queries work, few fails .. mostly all are complex select queries.

It's a long shot, because I expect you're running the usual packages
under a user set up by the package to be a "system" user, but just in
case: there is one known way for POSIX shm to be unlinked while you're
still using it: systemd. For example, this might happen if you have
cronjobs running as the same user. Some more info:

https://www.postgresql.org/docs/11/kernel-resources.html#SYSTEMD-REMOVEIPC

Do you see any other errors around this one, in the PostgreSQL logs?