[mdaniel]

I got nerd-sniped on this, because I actually hadn't heard that before and would be horrified if it were true. It took some non-trivial digging to even get down into the "well, what does foo->>'bar' even map to in C?" level. I for sure am not claiming certainty, but based merely on "getIthJsonbValueFromContainer" <https://sourcegraph.com/github.com/postgres/postgres@REL_17_...> it does seem that they do palloc copies for at least some of the JSONB calls

[anarazel]

Postgres does have infrastructure to avoid this in cases where the result is reused, and that's used in other places, e.g. array constructors / accessors. But not for jsonb at the moment.