Wrap function expressions for generated columns in parens

[fulghum]

No description provided.

[github-actions]

	Main	PR
covering_index_scan_postgres	368.84/s	369.76/s	+0.2%
index_join_postgres	152.81/s	152.69/s	-0.1%
index_join_scan_postgres	183.36/s	184.42/s	+0.5%
index_scan_postgres	12.53/s	12.51/s	-0.2%
oltp_point_select	2781.05/s	2784.74/s	+0.1%
oltp_read_only	1877.60/s	1883.25/s	+0.3%
select_random_points	112.30/s	112.75/s	+0.4%
select_random_ranges	130.98/s	131.72/s	+0.5%
table_scan_postgres	11.79/s	11.69/s	-0.9%
types_table_scan_postgres	5.61/s	5.55/s	-1.1%

[github-actions]

	Main	PR
Total	42090	42090
Successful	15377	15383
Failures	26713	26707
Partial Successes1	5238	5237

	Main	PR
Successful	36.5336%	36.5479%
Failures	63.4664%	63.4521%

${\color{lightgreen}Progressions (6)}$

generated

QUERY: CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED NOT NULL);

QUERY: INSERT INTO gtest21a (a) VALUES (1);

QUERY: CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED);

QUERY: ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;

QUERY: INSERT INTO gtest21b (a) VALUES (1);

QUERY: ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;

Footnotes

1. These are tests that we're marking as Successful, however they do not match the expected output in some way. This is due to small differences, such as different wording on the error messages, or the column names being incorrect while the data itself is correct. ↩

[zachmu]

LGTM