Fast count of table rows in PostgreSql

tables_count_postgre.sql

create or replace function 
count_rows(schema text, tablename text) returns integer
as
$body$
declare
  result integer;
  query varchar;
begin
  query := 'SELECT reltuples::bigint AS estimate FROM pg_class WHERE oid = to_regclass(''' || schema || '.' || tablename || ''')';
  execute query into result;
  return result;
end;
$body$
language plpgsql;

select 
  table_schema,
  table_name, 
  count_rows(table_schema, table_name)
from information_schema.tables
where 
  table_schema not in ('pg_catalog', 'information_schema', 'partman') 
  and table_type='BASE TABLE'
order by 3 desc