Perhaps a redundant column (based on sequence generators)

Copy SQL

WITH defs AS (SELECT c.table_schema, t.table_type, c.table_name, c.column_name,  c.data_type, c.domain_schema, c.domain_name, coalesce(c.column_default, domain_default) AS default_value,
CASE WHEN c.column_default IS NOT NULL THEN 'Column default' ELSE 'Domain default' END AS default_type
FROM information_schema.columns AS c LEFT JOIN information_schema.domains d USING (domain_schema, domain_name)
INNER JOIN INFORMATION_SCHEMA.tables AS t  USING (table_schema, table_name)
WHERE c.table_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL) 
AND (column_default IS NOT NULL OR domain_default IS NOT NULL))
SELECT table_schema, table_name, table_type, Count(*) AS nr_of_surrogates, string_agg(column_name || '(' || data_type || ')' || ' ' || default_value,';<br>' ORDER BY table_schema, table_name) AS columns
FROM defs
WHERE default_value~*'.*nextval[(]'
GROUP BY table_schema, table_name, table_type
HAVING Count(*)>1
ORDER BY Count(*) DESC, table_schema, table_name;