/* Index hit rate (effective databases are at 99% and up) */

SELECT relname,

  CASE idx_scan
    WHEN 0 THEN 'Insufficient data'
    ELSE (100 * idx_scan / (seq_scan + idx_scan))::text
  END percent_of_times_index_used,
  n_live_tup rows_in_table
FROM
  pg_stat_user_tables
ORDER BY
  n_live_tup DESC;