How to turn off the auto updatedb and run it manually?

[Yin Ming]

Hi, boys.

My box is pretty old, so running a updatedb (for locate DB) is a bit
slow and takes too much cpu time. I seldom install something or move
files, and, in fact, I rarely use locate. So it's not necessary to run
updatedb every day. 

I search /etc/rc.d, and those profiles in /etc, but didn't find anyone
calling updatedb, so I don't know how to make it not run everyday
automatically, or change its frequency to a week once. Where can I set
its schedule of updatedb?