A common task when managing databases is checking the length/size of data stored within tables, particularly if you're having performance issues. The INFORMATION_SCHEMA database is always a great start for queries like this, but it can be duanting when your just starting out.
If you're using MySQL here is a handy SQL statement that will show your the size of table data and indexes within the specified schema (don't forget to alter the reference to <your_schema> in the where clause!)
select table_schema, table_name,
concat( round( data_length / ( 1024 *1024 ) , 2 ) , 'Mb' ) data_length_mb,
concat( round( index_length / ( 1024 *1024 ) , 2 ) , 'Mb' ) index_length_mb,
concat( round( round( data_length + index_length ) / ( 1024 *1024 ) , 2 ) , 'Mb' ) total_size_mb
where table_schema like '<your_schema>'
order by data_length desc;
I hope this helps, and if it does then please let me know!
Daniel Bryant (Director) | Tai-Dev Ltd www.tai-dev.co.uk - IT Consultancy Services Specialising in JEE, Web 2.0 and RDBMS