I've read [total size of data](https://stackoverflow.com/questions/5011766/how-do-you-find-out-the-total-size-of-the-data-in-mysql-database), [determine space of a particular table](https://stackoverflow.com/questions/6474591/how-can-you-determine-how-much-disk-space-a-particular-mysql-table-is-taking-up), etc., but am wondering, is it possible to find the total space a specific user in the table is using (like how GMail shows you how much total space you've used.)?

Say I have user\_id 1 who has 100 private messages (not in a folder, simply in the db) and 10 file uploads (whose location are stored in the db). These are all in 3 separate tables, but they do take up MySQL space). Is it possible to create a query that gives me a total of all that space for that user?