Thanks - that looks like it.
> If so, does it make sense that some values of the keys would have a lot of duplicates?
Yes the indexes aren't unique so thousands of duplicates.
I'm a little surprised that the number of these that get reported is so small.
Dumping and reloading isn't really achievable on this size of server when its in production. We'll have to go for dropping the indexes.
Thanks -at least we know what it is.