Getting the date/time of the last change to a MySQL database

SELECT update_time
FROM   information_schema.tables
WHERE  table_schema = 'dbName'
       AND table_name = 'tableName'

I found this metod, from http://mysqladministrators.blogspot.it/2012/02/get-database-size.html

I'm not sure if it can help you, since i'm not so prepared in MySql

Get the database size, free space and last update

To get the current database size just by querying into your query browser or CLI from the INFORMATION_SCHEMA database in table TABLES.

SELECT table_schema "Data Base Name", 
sum( data_length + index_length ) / 1024 / 1024 "Data Base Size in MB" 
FROM information_schema.TABLES 
GROUP BY table_schema ;

Get the database free space

SELECT table_schema "Data Base Name", 
sum( data_length + index_length ) / 1024 / 1024 "Data Base Size in MB", 
sum( data_free )/ 1024 / 1024 "Free Space in MB" 
FROM information_schema.TABLES 
GROUP BY table_schema;

Get the database last update ordered by update time then by create time.

SELECT MAX(UPDATE_TIME), MAX(CREATE_TIME), TABLE_SCHEMA 
FROM `TABLES` 
GROUP BY TABLE_SCHEMA 
ORDER BY 1, 2;