How to make TokuDB engine on Percona delete faster
If your table has 1 or more secondary indexes than each delete requires a read on the primary key index to get the fields necessary for the deletes in each secondary, which eliminates much of the TokuDB advantage over InnoDB. Also, if your delete pattern is "left-most" or you are performing a large number of deletes in a specific key range you will likely end up with quite a bit of garbage in your Fractal Tree indexes which will need to be cleaned up by optimizing the table/indexes.