which mysql 32 / 64 bit

How good it'd be to have 64 bit MySQL on 64 bit Linux ofcouse? Presently I have 32bit Mysql / OS but 64bit hardware. Shall I consider u开发者_开发知识库pgrade? What advantages do I have?

You will get the main advantage of 64bit software - you will be able to address more RAM

What advantages do I have?

Potentially bigger in-memory caches. And big caches can really help database performance ... in some cases. However, I've also noticed evidence that suggests that there is a limit to which application caches help, and that in some situations a OS level file caches work better at reducing disc IO delays.

For some hints on how 64bit MySQL (with appropriate tuning) might help, read How MySQL Uses Memory from the MySQL manual.