record size and table size with ActiveRecord?

What is the best way to find the record size and table size in a
database using ActiveRecord? And will that method indicate actual disk
space?

If not, how do I do it with SQL commands?

Thanks!
chirag

chirag wrote:

What is the best way to find the record size and table size in a
database using ActiveRecord? And will that method indicate actual disk
space?

Here's something I use with MySQL:

def self.table_size_in_bytes
   connection.select_one("show table status like '#{table_name}'")['Data_length'].to_i
end