Sorry but adding a new index on a table with 6 billion rows is stupid. If you did this in production, it would take that table offline for possibly days. And if it somehow failed, you would be SOL.<p>You create a copy of the table with an updated set of indexes and copy the data over into the new table. I think Percona even has a utility that will copy all the next data over via stored procedure that is getting written to the table.