Hello,
I have two tables with the same fields (fields: email, first name, lastname, address, etc). One table will be the master table (the size is about 2 million to 3 million records) and the other table will be the child table (40000 - 80000 records).
What I want to do is, to compare the email field in the child table to the master table. If an email address in the child table already exists in the master table, I want to delete that record from the child table. If an email address in the child table doesn't already exist in the master table, I want that record to be added to the master table but not deleted from the child table.
What is the best way or algorhytm to tackle this problem? And is this deduping process going to take a long time?
Any help or input would be appreciated very very very much.
Thank you very much,
Renny
