The following bug has been logged on the website:
Bug reference: 17494
Logged by: Владимир Пашутин
Email address: pashutin@gmail.com
PostgreSQL version: 11.14
Operating system: any
Description:
When working with sorting large lists, we often encounter an error:
SQL state [XX000]; error code [0]; ERROR: could not resize shared memory
segment \"/PostgreSQL.932873081\" to 100868096 bytes: Interrupted system
call; nested exception is org.postgresql.util.PSQLException: ERROR: could
not resize shared memory segment \"/PostgreSQL.932873081\" to 100868096
bytes: Interrupted system call
But we almost never need the whole list. Requests are always limited with
LIMIT and OFFSET.
However, from the analysis of the query plan, it turns out that first there
is a complete sorting of the entire result and only then the selection of
the required part of the rows.
This is not much of a bug report. PostgreSQL does have top-N sorts. Why it is not used for some particular query is impossible to say without seeing the query and/or query plan.
Even if not using top-N, it should still spill to disk instead of erroring out like that, assuming your memory/parallel settings and load are reasonable for your server. Again, with this amount of detail there is no way to know.
Cheers,
Jeff