Re: Keeping clean pages in shared memory

Andy Kent writes: |> OK, so every Online person knows how the most frequently-used pages are |> encouraged to stay in shared memory by means of LRU queues. |> |> That's fine for dirty pages. A potentially dumb question then: what |> about clean ones? Does OnLine have a mechanism for ensuring that the |> most-frequently *read* pages don't get overwritten? When choosing a buffer to load new data into, OnLine will take a buffer from the least recently used end of the clean queue (as of 5.0 or so, each LRU queue was actually a pair of queues, one for clean buffers and one for dirty buffers). Thus a page that is frequently read stays in memory. You assume LRU only applies to dirty pages; that assumption is incorrect. Dave Kosenko Disclaimer: All opinions expressed in this message are well-reasoned and insightful; needless to say, they are not those of Informix Software, its partners or lackeys. Anyone who says otherwise is itching for a fight. **************************************************************************** "I look back with some satisfaction on what an idiot I was when I was 25, but when I do that, I'm assuming I'm no longer an idiot." - Andy Rooney