Come trovi la dimensione del disco di una tabella Postgres / PostgreSQL e dei suoi indici

Prova le funzioni di dimensione dell'oggetto del database. Un esempio:

SELECT pg_size_pretty(pg_total_relation_size('"<schema>"."<table>"'));

Per tutte le tabelle, qualcosa sulla falsariga di:

SELECT
    table_schema || '.' || table_name AS table_full_name,
    pg_size_pretty(pg_total_relation_size('"' || table_schema || '"."' || table_name || '"')) AS size
FROM information_schema.tables
ORDER BY
    pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') DESC;

Modifica:ecco la query inviata da @phord, per comodità:

SELECT
    table_name,
    pg_size_pretty(table_size) AS table_size,
    pg_size_pretty(indexes_size) AS indexes_size,
    pg_size_pretty(total_size) AS total_size
FROM (
    SELECT
        table_name,
        pg_table_size(table_name) AS table_size,
        pg_indexes_size(table_name) AS indexes_size,
        pg_total_relation_size(table_name) AS total_size
    FROM (
        SELECT ('"' || table_schema || '"."' || table_name || '"') AS table_name
        FROM information_schema.tables
    ) AS all_tables
    ORDER BY total_size DESC
) AS pretty_sizes;

L'ho leggermente modificato per usare pg_table_size() per includere i metadati e far sommare le dimensioni.