Largest tables and columns in a MySQL database

list_column_size.sql

SELECT CONCAT(ROUND(sum(length(column_name)) / ( 1024 * 1024 ), 2), 'M')
	FROM table_name;

list_largest_tables.sql

SELECT CONCAT(table_schema, '.', table_name),
       CONCAT(ROUND(table_rows / 1000000, 2), 'M')                                    rows,
       CONCAT(ROUND(data_length / ( 1024 * 1024 ), 2), 'M')                    DATA,
       CONCAT(ROUND(index_length / ( 1024 * 1024 ), 2), 'M')                   idx,
       CONCAT(ROUND(( data_length + index_length ) / ( 1024 * 1024 ), 2), 'M') total_size,
       ROUND(index_length / data_length, 2)                                           idxfrac
FROM   information_schema.TABLES
ORDER  BY data_length + index_length DESC
LIMIT  25;