does mysqlhotcopy affect the key buffer?

[Tom Worster]

i run mysqlhotcopy on each database once every three hours.

i happened to be running my cache warmer this afternoon, which logs timing
for a bunch of standard randomized queries, that when the backup script ran,
the query times increased by a factor of about 20 from a nice quick pace
back down to what i'd expect for an empty cache. hot times then slowly
settled back down to the faster pace as i would expect as cold caches warm
up. (i really don't know if key or table caches are the bottleneck.)

so i was wondering if mysqlhotcopy has affecting the caches.