check_index_size.sql

SELECT
    nspname,relname,relkind,
    round(100 * pg_relation_size(indexrelid) / pg_relation_size(indrelid)) / 100
      AS index_ratio,
    pg_size_pretty(pg_relation_size(indexrelid)) AS index_size,
    pg_size_pretty(pg_relation_size(indrelid)) AS table_size
FROM pg_index I
LEFT JOIN pg_class C ON (C.oid = I.indexrelid)
LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
WHERE
  relname IN ('accounts_pkey') AND
  pg_relation_size(indrelid) > 0;