foreign key creation in a huge database

[Raffael Vendrametto]

Hi,


I am working in a huge database, I am trying to insert foreign key in a table with more than 11 millions rows, but is giving me a error;

ERROR 1452: Cannot add or update a child row: a foreign key constraint fails

I deleted all data and created the foreign before import, but during the import I received the same error:

ERROR 1452: Cannot add or update a child row: a foreign key constraint fails

So what I need to do is discovery what rows is not matching on the parent table.

but for do it, I need to run a query to verify this two tables one 11 millions rows and the parent table 3millions rows, without foreign key, this is taking a day, and giving me a error off timeout, which is already too increased.

I would like to know if anyone has any option to solve this problem.
Please this problem should be solved urgent!!!

Thank you!!!