Inside my summer time internship this season, I have received the project of attempting to wash up our database. I have found an answer on here that informs me to make use of the data_Schema.tables UPDATE_TIME column, HOWEVER, 95% from the UPDATE_TIME fields are NULL, even on tables I understand our programs hook into increase every day. So I'm wondering if there is another simple way to try and determine what tables weren't used shortly.

Thanks!

Presuming no tables are read-only, you can setup triggers to ensure that when values are erased or up-to-date, a row is up-to-date inside a logging table. You'll be able to let it rest running to have an appropriate period of time to determine what tables weren't up-to-date.

I do not believe there's a method to directly check which tables happen to be used lately. When the tables or MyISAM, or even the server is applying innodb_file_per_table, you might have the ability to consider the last modified occasions from the tables within the data directory. I'd suspect this wouldn't produce any false positives regarding rarely utilized tables, however, you might acquire some false disadvantages.