I haven't notice a gain from increasing the key_buffer on a dedicated
slave. Let's take 3.23.5x for instance. Since there is only 1 thread for
replication, a Serialized committal of data, I wouldn't imagine that
key_buffer at higher levels say around 50% of system memory would give a
performance boost. In fact raising sort_buffer, read_buffer,
read_rnd_buffer would be more of a win to reduce lock times so committal
of the data happens faster.
Is this observation wrong? Does raising key_buffer on a slave to around
50% of the memory available make a difference?
- Dathan Vance Pattishall
- Sr. Programmer and mySQL DBA for FriendFinder Inc.