Could someone explain why dropping a primary key of a table (of
~1million rec) may take up to minutes of time and 99%CPU?
Naively, I would have thought that this involves only updating the
However, all the .MYD, MYI and .frm files are duplicated (#sql-*), and
then something happens for quite a bit of time.
Is this related to the fact that I have more indexes in the table, and
those are retained?
I guess MySQL is doing something intelligent, but I did not find a
source that explains the procedure ... what exactly happens.