Get the disk space used by tables and indexes on all the tables in a PostgreSQL database.

WITH indexsizes AS (
    SELECT  C .oid,
            relname AS "relation",
            nspname,
            pg_size_pretty (
                pg_total_relation_size (C .oid)
            ) AS "total_size"
        FROM
            pg_class C
        LEFT JOIN pg_namespace N ON (N.oid = C .relnamespace)
        WHERE
            nspname NOT IN (
                'pg_catalog',
                'information_schema'
            )
        AND C .relkind <> 'i'
        AND nspname !~ '^pg_toast')
SELECT  nspname,
        relation,
        pg_size_pretty(pg_table_size(oid)) AS table_size,
        pg_size_pretty(pg_indexes_size(oid))  AS index_size,
        pg_size_pretty(pg_total_relation_size(oid)) AS total_size
    FROM indexsizes
    ORDER BY pg_total_relation_size(oid);