WITH nullability_pattern AS (SELECT table_schema, table_name, 
string_agg(CASE WHEN is_nullable='NO' THEN 'M' ELSE 'O' END,'' ORDER BY ordinal_position) AS pattern
FROM INFORMATION_SCHEMA.columns
WHERE (table_schema, table_name) IN (SELECT table_schema, table_name
FROM INFORMATION_SCHEMA.tables WHERE table_type='BASE TABLE') AND 
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)
GROUP BY table_schema, table_name)
SELECT table_schema, table_name, pattern
FROM nullability_pattern
WHERE pattern!~'^M+O*$'
ORDER BY table_schema, table_name;