Re: Checkpoint Question - need feedback

On Wed, 05 Jul 2006 17:21:30 -0500, Madison Pruet <mpruet@comcast.net> wrote: >I've got a question for the user community. > >Checkpoints are a real pain because there is a period of time in which >user threads are going to be blocked. > >I've been playing around with an idea in which I think I could do >non-blocking checkpoints. The cost of doing this, however, would be >that there would probably need to be a significant increase in the size >of the physical log file. > >I know that implementing the fractional LRU min/max has helped reduce >the impact of the checkpoint, but the fractional LRU min/max is not a >guarantee - since it is possible that the LRU page writers won't be able >to keep up with the current activity. > >Also - this idea would eliminate fuzzy checkpoints, which is probably a >good thing since fuzzy checkpoints do impact the recovery time of the >server. > >So - basic question --- Is the cost of the increased physical log file >(maybe 3-4 times larger in some cases) totally outweigh the benefit of >non-blocking checkpoints? Sounds reasonable to me . . . . but would it be a conversion/upgrade requirement, or a feature that would be available to use at a later date? JWC