On Sun, Apr 09, 2006 at 08:23:36AM -0700, Myron Scott wrote: > >This is the part I'm curious about - is this using the > >shared_buffers region > >in a circular buffer fashion to store pre-fetched pages? > > Yes. That is basically what the slave thread is trying to do. As > well as weed out > any tuples/pages that don't need to be looked at due to dead tuples. > I did several things to try and insure that a buffer needed by the > master thread > would not be pulled out of the buffer pool before it was seen by the > master. > I wanted to do this without holding the buffer pinned, so I did the > change to > the buffer free list to do this.
Is this necessary? I mean, what's the chance that a page might get thrown out early? And if so, what's the chance that page will still be in the OS cache? The cost of fetching a page from the OS is not really much of an overhead, so I'd like to know how much benefit these buffer cache hacks actually produce. Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.
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