Postgres Return statistic(size, rows count) from all tables in current DataBase

pgsql-query-size-and-rowCount.sql

/*
  Return statistic from all tables in current DataBase

+------------------+----------+-------+--------------+
| tableName        | rowCount | size  | externalSize |
+------------------+----------+-------+--------------+
| mails            | 101      | 64kb  | 48kb         |
+------------------+----------+-------+--------------+
| "logs"           | 25       | 104kb | 56kb         |
+------------------+----------+-------+--------------+
| "mail_templates" | 2        | 112kb | 96kb         |
+------------------+----------+-------+--------------+
| "campaigns"      | 2        | 64kb  | 56kb         |
+------------------+----------+-------+--------------+
*/

SELECT
  pgClass.relname   AS tableName,
  CAST(pgClass.reltuples AS INT) AS rowsCount,
  pg_size_pretty(pg_total_relation_size(relid)) As "size",
  pg_size_pretty(pg_total_relation_size(relid) - pg_relation_size(relid)) as "externalSize"
FROM
  pg_class pgClass
LEFT JOIN
  pg_namespace pgNamespace ON (pgNamespace.oid = pgClass.relnamespace)
LEFT JOIN
  pg_catalog.pg_statio_user_tables ON pg_catalog.pg_statio_user_tables.relname = pgClass.relname
WHERE
  pgNamespace.nspname NOT IN ('pg_catalog', 'information_schema') AND
  pgClass.relkind='r' AND
  pgClass.reltuples > 1
ORDER BY pg_total_relation_size(relid) DESC, pgClass.reltuples DESC

LIMIT 35