HOWTO: Show a summary of data used by all MySQL tables

Here is a useful MySQL command that shows (an approximation of) the amount of storage (disk and memory) consumed by each table in a MySQL database.

SELECT
 TABLE_NAME,
 TABLE_ROWS,
 DATA_LENGTH / (1024*1024),
 INDEX_LENGTH / (1024*1024),
 (DATA_LENGTH + INDEX_LENGTH) / (1024*1024) as total
FROM
 information_schema.TABLES
WHERE
 TABLE_SCHEMA = (SELECT DATABASE())
GROUP BY
 TABLE_NAME
ORDER BY
 total;

Please bear in mind that the data returned will be an approximation, but should still show you a reasonable enough split which of your tables are consuming most of the resources.