WITH tables AS (SELECT nspname AS table_schema, relname AS table_name, 
CASE WHEN relkind='r' THEN 'BASE TABLE' 
WHEN relkind='m' THEN 'MATERIALIZED VIEW' 
ELSE 'VIEW' END AS table_type
FROM pg_class INNER JOIN pg_namespace ON pg_class.relnamespace=pg_namespace.oid
WHERE relkind IN ('r', 'm','v') AND 
nspname NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL))
SELECT table_type, length(table_name) AS length, Count(*) AS nr_of_occurrences, Round(Count(*)::decimal*100/(SELECT Count(*) FROM tables AS t2 WHERE t2.table_type=tables.table_type),1) AS percentage_of_all_columns
FROM tables
GROUP BY table_type, length(table_name)
ORDER BY table_type, length;