update statistics medium/high: how often?

What are some good guidelines for determining how often I should run an update statistics high or medium? -- Cos (Ofer Inbar) -- cos@leftbank.com cos@cs.brandeis.edu -- The Left Bank Operation -- lbo@leftbank.com http://www.leftbank.com It's been said that if a sysadmin does his job perfectly, he's the fellow that people wonder what he does and why the company needs him, until he goes on vacation. -- comp.unix.admin FAQ