On Mon, 18 Dec 2023 at 16:34, Jelte Fennema-Nio <postg...@jeltef.nl> wrote: > > On Mon, 18 Dec 2023 at 16:38, Christoph Berg <m...@debian.org> wrote: > > We'd want both patches even if they do the same thing on two different > > levels, I'd say. > > Makes sense. >
I can see the appeal in this feature. However, as it stands, this isn't compatible with copy format json, and I think it would need to duplicate quite a lot of the JSON output code in client-side code to make it compatible. Consider, for example: CREATE TABLE foo(col json); INSERT INTO foo VALUES ('"str_value"'); copy foo to stdout with (format json) produces this: {"col":"str_value"} which is as expected. However, psql -Jc "select * from foo" produces [ { "col": "\"str_value\"" } ] The problem is, various datatypes such as boolean, number types, json, and jsonb must not be quoted and escaped, since that would change them to strings or double-encode them in the result. And then there are domain types built on top of those types, and arrays, etc. See, for example, the logic in json_categorize_type(). I think that trying to duplicate that client-side is doomed to failure. Regards, Dean