Andres Freund <and...@anarazel.de> writes: > Is there a guarantee that input functions are stable or immutable?
There's a project policy that that should be true. That justifies marking things like record_in as stable --- if the per-column input functions could be volatile, record_in would need to be as well. There are other dependencies on it; see e.g. aab353a60, 3db6524fe. > We don't > have any volatile input functions in core PG: Indeed, because type_sanity.sql checks that. regards, tom lane