feat(binder): enhance support of struct.* (and table.*)

[xiangjinwu]

https://www.postgresql.org/docs/15/rowtypes.html#ROWTYPES-USAGE

In PostgreSQL, a reference to a table name (or alias) in a query is effectively a reference to the composite value of the table's current row. For example, if we had a table inventory_item as shown above, we could write:

SELECT c FROM inventory_item c;

In addition, the interpretation of .* can be different in different context:

The composite_value.* syntax results in column expansion of this kind when it appears at the top level of a SELECT output list, a RETURNING list in INSERT/UPDATE/DELETE, a VALUES clause, or a row constructor. In all other contexts (including when nested inside one of those constructs), attaching .* to a composite value does not change the value, since it means “all columns” and so the same composite value is produced again. For example, if somefunc() accepts a composite-valued argument, these queries are the same:

SELECT somefunc(c.*) FROM inventory_item c;
SELECT somefunc(c) FROM inventory_item c;

In practice, builtin functions that accept a composite-valued argument are rare: most are the ones accept any types, for example count.

This results in the following behavior in PostgreSQL:

test=# create table a(a1 int); insert into a values (2), (null), (3);
CREATE TABLE
INSERT 0 3

test=# create table b(b1 int); insert into b values (3), (null);
CREATE TABLE
INSERT 0 2

test=# select count(*), count(b.*), count(b1) from a left join b on a1 = b1;
 count | count | count 
-------+-------+-------
     3 |     1 |     1
(1 row)

test=# select count(*), count(b.*), count(b1) from a left join b on a1 is not distinct from b1;
 count | count | count 
-------+-------+-------
     3 |     2 |     1
(1 row)

test=# select a.*, b.*, a, b, b is null from a left join b on a1 = b1 order by a1;
 a1 | b1 |  a  |  b  | ?column? 
----+----+-----+-----+----------
  2 |    | (2) |     | t
  3 |  3 | (3) | (3) | f
    |    | ()  |     | t
(3 rows)

test=# select a.*, b.*, a, b, b is null from a left join b on a1 is not distinct from b1 order by a1;
 a1 | b1 |  a  |  b  | ?column? 
----+----+-----+-----+----------
  2 |    | (2) |     | t
  3 |  3 | (3) | (3) | f
    |    | ()  | ()  | t
(3 rows)

Notes:

• count(b.*) is not same as count(*) or count(b1) during outer join.
• CockroachDB v22.2.6 and Duckdb v0.7.1 both return 3, 3, 1 for the counts, because their join did not return NULL (but () a struct with a null field) for the composite value b.
• PG-incompatibility: IS NULL of all-null row/struct #10150

Tentatively assigning low priority due to its complexity and rare usage. We do see one query using count(t.*) #10838 but it is an inner join.