query tables in mirth database by size

gistfile1.sql

SELECT nspname || '.' || relname AS "relation",
    pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
    , SUBSTRING(relname FROM '[0-9]+')
    , d.*
    , ch.name
  FROM pg_class C
  LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
  LEFT JOIN d_channels d ON cast(d.local_channel_id as varchar(5)) = SUBSTRING(relname FROM '[0-9]+')
  LEFT JOIN channel ch ON ch.id = d.channel_id
  WHERE nspname NOT IN ('pg_catalog', 'information_schema')
    AND C.relkind <> 'i'
    AND nspname !~ '^pg_toast'
  ORDER BY pg_total_relation_size(C.oid) DESC