Get table row counts quickly in PostgreSQL

30 Jul 2015

These row counts won't be as exact as

select count(*) from my_table

select n_live_tup as rough_row_count 
  from pg_stat_user_tables 
 where schemaname = 'public' 
   and relname = 'my_table';

or

select t.reltuples as rough_row_count 
  from pg_class as t 
  join pg_namespace as s on t.relnamespace = s.oid 
 where s.nspname = 'public' 
   and t.relname = 'my_table';