information_schema.view attgenerated

hi.
one minor issue in src/backend/catalog/information_schema.sql
/*
 * 6.22
 * COLUMNS view
 */
CREATE VIEW columns ....


CAST(CASE WHEN a.attgenerated = '' THEN pg_get_expr(ad.adbin,
ad.adrelid) END AS character_data) AS column_default,
can change to
CAST(CASE WHEN a.attgenerated = '' AND a.atthasdef THEN
pg_get_expr(ad.adbin, ad.adrelid) END AS character_data) AS
column_default,


CAST(CASE WHEN a.attgenerated <> '' THEN 'ALWAYS' ELSE 'NEVER' END AS
character_data) AS is_generated,
can change to
CAST(CASE WHEN a.attgenerated <> '' AND a.atthasdef THEN 'ALWAYS' ELSE
'NEVER' END AS character_data) AS is_generated,

CAST(CASE WHEN a.attgenerated <> '' THEN pg_get_expr(ad.adbin,
ad.adrelid) END AS character_data) AS generation_expression,
can change to
CAST(CASE WHEN a.attgenerated <> '' AND a.atthasdef THEN
pg_get_expr(ad.adbin, ad.adrelid) END AS character_data) AS
generation_expression,


i guess, it will have some minor speed up, also more accurate.