title: Simulating MySql 5.7 delete query
body: <p>I am working on purging a huge database (~ 1TB data ) with over 10 million records using InnoDB engine. Whoever set up the database schema, set the foreign keys but did not set on delete cascade. I want to do a selective time based purge. Two parts to my question</p>
  
  <ol>
  <li>Can I set "on delete cascade" without any side-effects ?</li>
  <li>Can I simulate my delete to check for foreign key reference violation ? I know I can use START TRANSACTION and ROLLBACK<br>
  TRANSACTION, but it is not something I am looking for</li>
  </ol>