Re: SQL:2023 JSON simplified accessor support

Hi Alex!

Glad you made so much effort to develop this patch set!
I think this is an important part of Json functionality.

I've looked into you patch and noticed change in behavior
in new test results:

postgres(at)postgres=# create table t(x int, y jsonb);
insert into t select 1, '{"a": 1, "b": 42}'::jsonb;
insert into t select 1, '{"a": 2, "b": {"c": 42}}'::jsonb;
insert into t select 1, '{"a": 3, "b": {"c": "42"}, "d":[11, 12]}'::jsonb;
CREATE TABLE
Time: 6.373 ms
INSERT 0 1
Time: 3.299 ms
INSERT 0 1
Time: 2.532 ms
INSERT 0 1
Time: 2.453 ms

Original master:
postgres(at)postgres=# select (t.y).b.c.d.e from t;
ERROR: column notation .b applied to type jsonb, which is not a composite
type
LINE 1: select (t.y).b.c.d.e from t;
^
Time: 0.553 ms

Patched (with v11):
postgres(at)postgres=# select (t.y).b.c.d.e from t;
e
---

(3 rows)

Is this correct?

--
Regards,
Nikita Malakhov
Postgres Professional
The Russian Postgres Company
https://postgrespro.ru/