Postgres check indexes statistics

indexes_not_in_use.sql

SELECT
    relid::regclass AS table,
    indexrelid::regclass AS index,
    pg_size_pretty(pg_relation_size(indexrelid::regclass)) AS index_size,
    idx_tup_read,
    idx_tup_fetch,
    idx_scan
FROM
    pg_stat_user_indexes
    JOIN pg_index USING (indexrelid)
WHERE
    idx_scan = 0
    AND indisunique IS FALSE;

pg_indexes.sql

SELECT t.tablename,
       indexname,
       c.reltuples AS num_rows,
       pg_size_pretty(pg_relation_size(quote_ident(t.tablename)::text)) AS table_size,
       pg_size_pretty(pg_relation_size(quote_ident(indexrelname)::text)) AS index_size,
       CASE
           WHEN indisunique THEN 'Y'
           ELSE 'N'
       END AS UNIQUE,
       idx_scan AS number_of_scans,
       idx_tup_read AS tuples_read,
       idx_tup_fetch AS tuples_fetched
FROM pg_tables t
LEFT OUTER JOIN pg_class c ON t.tablename=c.relname
LEFT OUTER JOIN
  (SELECT c.relname AS ctablename,
          ipg.relname AS indexname,
          x.indnatts AS number_of_columns,
          idx_scan,
          idx_tup_read,
          idx_tup_fetch,
          indexrelname,
          indisunique
   FROM pg_index x
   JOIN pg_class c ON c.oid = x.indrelid
   JOIN pg_class ipg ON ipg.oid = x.indexrelid
   JOIN pg_stat_all_indexes psai ON x.indexrelid = psai.indexrelid) AS foo ON t.tablename = foo.ctablename
WHERE t.schemaname='public'
ORDER BY 1, 2;