I got a question a while ago that I thought was quite simple, but turned into an interesting discussion: How much hard disk space does a database take up?
As it happens, there's a simple answer and a much, much more involved (yet ill-defined) answer, and which one you choose depends on what you think goes into a database and how very, very pedantic you are.
The Simple Answer
You can query the size of table and index data using Information Schema or SHOW TABLE STATUS. The columns DATA_LENGTH and INDEX_LENGTH contain the number of bytes for the table and index data respectively. You can construct simple queries based on that data, or do a quick search on the web for more interesting queries (For example, Peter Zaitsev of Percona wrote a post …[Read more]