Listando as 10 maiores tabelas no PostgreSQL

top-10-tables_by-size.sql

WITH table_stats AS (
	SELECT
		schemaname,
		tablename,
		pg_relation_size(schemaname || '.'|| tablename) as table_size,
		(pg_total_relation_size(schemaname || '.'|| tablename) - pg_relation_size(schemaname || '.'|| tablename)) as index_size,
		pg_total_relation_size(schemaname || '.'|| tablename) as total_size
	FROM
		pg_tables
)
SELECT
	table_stats.schemaname,
	table_stats.tablename,
	pg_size_pretty(table_stats.table_size) as table_size,
	pg_size_pretty(table_stats.index_size) as index_size,
	pg_size_pretty(table_stats.total_size) as total_size
FROM
	table_stats

WHERE
	-- ajuste o filtro conforme sua necessidade!
	table_stats.schemaname = 'public'
ORDER BY
	table_stats.total_size desc,
	table_stats.index_size desc,
	table_stats.table_size desc
LIMIT 10;