I'm about to drop an index from a mySQL INNODB table. There are references defined already. When I try to alter it, it says: #1025 - Error on rename of 'X/#sql-2a5f_219828' to 'X' (errno: 150) ...
I need to alter a large table in order to add a foreign key. Does adding the constraint cause the table to be rebuilt? The referenced table already exists and has an index on the column.