with keys as (select 
(select nspname from pg_namespace where oid=c.relnamespace) as key_schema,
c.relname as key_table, 
c.oid as key_table_oid,
o.conkey AS key_col
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype in ('u', 'p') and cardinality(o.conkey)=1),
keys_unnest as (select key_schema, key_table, key_table_oid, key_col, key_col_num, ordin
from keys, unnest(keys.key_col) with ordinality as k(key_col_num, ordin)),
keys_with_names AS (select key_schema, key_table, a_key.attname as key_col
from keys_unnest k inner join pg_attribute a_key on k.key_col_num = a_key.attnum and k.key_table_oid = a_key.attrelid and a_key.attisdropped = false
),
fk as (select 
(select nspname from pg_namespace where oid=c.relnamespace) as key_schema,
c.relname as key_table, 
c.oid as key_table_oid,
o.conkey AS key_col
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype='f'),
fk_unnest as (select key_schema, key_table, key_table_oid, key_col, key_col_num, ordin
from fk, unnest(fk.key_col) with ordinality as k(key_col_num, ordin)),
fk_with_names AS (select key_schema, key_table, a_key.attname as key_col
from fk_unnest k inner join pg_attribute a_key on k.key_col_num = a_key.attnum and k.key_table_oid = a_key.attrelid and a_key.attisdropped = false),
key_not_fk AS (select key_schema, key_table, key_col
from keys_with_names
except select key_schema, key_table, key_col
from fk_with_names),

surrogate_key AS (
SELECT c.table_schema, c.table_name
FROM information_schema.columns c
LEFT JOIN information_schema.domains d USING (domain_schema, domain_name)
INNER JOIN information_schema.schemata s
ON c.table_schema=s.schema_name
WHERE (coalesce (c.column_default, d.domain_default) ILIKE '%nextval%'  
OR c.is_identity='YES') 
AND (c.table_schema = 'public'
OR s.schema_owner<>'postgres'))

SELECT c.table_schema, c.table_name , c.column_name
FROM information_schema.columns c
LEFT JOIN information_schema.domains d USING (domain_schema, domain_name)
INNER JOIN information_schema.schemata s
ON c.table_schema=s.schema_name
WHERE (coalesce (c.column_default, d.domain_default) NOT ILIKE '%nextval%' OR coalesce (c.column_default, d.domain_default) IS NULL) 
AND c.is_identity='NO' 
AND (c.column_name~*'_id$' OR c.column_name~*'^id_') 
AND c.data_type~*'(integer|smallint|bigint)'
AND (c.table_schema = 'public'
OR s.schema_owner<>'postgres')
AND EXISTS (SELECT 1
FROM key_not_fk AS k
WHERE k.key_schema=c.table_schema
AND k.key_table=c.table_name
AND k.key_col=c.column_name)
AND NOT EXISTS (SELECT 1
FROM surrogate_key AS sk
WHERE sk.table_schema=c.table_schema
AND sk.table_name=c.table_name)
ORDER BY table_schema, table_name;