sql: Remove type annotations from column_default in information_schema.columns

[e-mbrown]

Informs: #87774

The type annotation on column_default caused confusion in postgres compatible apps. This change formats the column_default without the type annotation. It does not address the incorrect type annotation.

Release note (bug fix): The content of column_default in information_schema.columns no longer have type annotations.

[cockroach-teamcity]

This change is 

[ZhouXing19]

LGTM!

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @e-mbrown and @rafiss)

---

pkg/sql/logictest/testdata/logic_test/information_schema line 2073 at r1 (raw file):

query TT colnames
select data_type, column_default  from information_schema.columns where table_name = 't2' and column_name = 'a';

nit: there's an extra space in front of from.

---

pkg/sql/logictest/testdata/logic_test/information_schema line 4915 at r1 (raw file):

other_db       public        t2          c            1
other_db       public        t2          d            2
test           public        t2          rowid        2

Hmm, this may have revealed another difference from PG. Seems that with postgres this rowid column won't show up.

postgres=# CREATE TABLE t1(a INT PRIMARY KEY, b BOOLEAN);
CREATE TABLE

postgres=# CREATE TABLE t2(a smallint DEFAULT 0);
CREATE TABLE

postgres=# SELECT table_catalog, table_schema, table_name, column_name, ordinal_position
FROM information_schema.columns where table_name = 't1' OR table_name = 't2';
 table_catalog | table_schema | table_name | column_name | ordinal_position
---------------+--------------+------------+-------------+------------------
 postgres      | public       | t2         | a           |                1
 postgres      | public       | t1         | a           |                1
 postgres      | public       | t1         | b           |                2

I can open an issue for this.

[e-mbrown]

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @rafiss and @ZhouXing19)

---

pkg/sql/logictest/testdata/logic_test/information_schema line 4915 at r1 (raw file):

Previously, ZhouXing19 (Jane Xing) wrote…

Hmm, this may have revealed another difference from PG. Seems that with postgres this rowid column won't show up.

postgres=# CREATE TABLE t1(a INT PRIMARY KEY, b BOOLEAN);
CREATE TABLE

postgres=# CREATE TABLE t2(a smallint DEFAULT 0);
CREATE TABLE

postgres=# SELECT table_catalog, table_schema, table_name, column_name, ordinal_position
FROM information_schema.columns where table_name = 't1' OR table_name = 't2';
 table_catalog | table_schema | table_name | column_name | ordinal_position
---------------+--------------+------------+-------------+------------------
 postgres      | public       | t2         | a           |                1
 postgres      | public       | t1         | a           |                1
 postgres      | public       | t1         | b           |                2

I can open an issue for this.

Opening an issue wouldn't hurt.

[e-mbrown]

TFTR Jane!

bors r=ZhouXing19

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)