PG Bug reporting form <noreply@postgresql.org> writes:
> We are encountering query execution issues on Postgres versions 13.10 to 16.
> When we execute numerous vacuum queries with in-application and auto-commit
> set to false, we receive the following error.
> Error: VACUUM cannot be performed within a pipeline.
You've provided no context about how you're invoking VACUUM, but
this error message suggests that you're doing so in a way that
causes it to be run as part of a multi-command transaction.
That's always been disallowed in theory, but the enforcement
was incomplete up until our Feb 2023 releases. You need to adjust
your application, or else convince us that whatever you're doing
should be allowed.
There's more context in this long thread:
https://www.postgresql.org/message-id/flat/17434-d9f7a064ce2a88a3%40postgresql.org
regards, tom lane