Re: LRU Parameters

Also sprach "Art S. Kagel" <kagel@bloomberg.com> : :By the way: Joao's CLEANERS value is much too low. With 32 LRUs one :should have 32 CLEANERS unless one has > 32 chunks then add more than :32 cleaners. You should have: #Chunks <= #CLEANERS >= #LRUs to :minimize checkpoint times. I don't know that I agree with that, at least if you are talking about a 7.X system. In 5.X, where CLEANERS actually handled performing the physical i/o, what Art states above is unquestionably true. However, with 7.X, CLEANERS are little more than administrative threads, going through the LRU queues or buffer pool and placing page pointers onto the i/o queues. This means they have a LOT less work to do (and never block), so a smaller number of cleaners should be able to handle a lot more work than their 5.0 brethren. Dave (posting from home, speaking as a representative of nobody but himself) ********** "Everybody plays the fool, sometimes."