Question about checkpoint!

[Raymond Raymond <ra...@hotmail.com>]

In current derby checkpoint implementation, a disk I/O burst
will be caused during checkpoint. To solve this problem, I am
trying to spread out the disk I/O of checkpoint over the checkpoint
interval. I found there are several things that can trigger a
checkpoint such as too much log generated since the last
checkpoint,data backup, before data compress, when a database
creation finished and so on. I am not sure should I spread out
the disk I/O of all kinds of checkpoint? or just the one triggered
when too much log has been generated since last checkpoint?

Thanks.


Raymond

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Re: Question about checkpoint!

[Suresh Thalamati <su...@gmail.com>]

Raymond Raymond wrote:
> In current derby checkpoint implementation, a disk I/O burst
> will be caused during checkpoint. To solve this problem, I am
> trying to spread out the disk I/O of checkpoint over the checkpoint
> interval. I found there are several things that can trigger a
> checkpoint such as too much log generated since the last
> checkpoint,data backup, before data compress, when a database
> creation finished and so on. I am not sure should I spread out
> the disk I/O of all kinds of checkpoint? or just the one triggered
> when too much log has been generated since last checkpoint?
> 
> Thanks.
> 
> 
> Raymond
> 
> _________________________________________________________________
> Powerful Parental Controls Let your child discover the best the Internet 
> has to offer.  
> http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU=http://hotmail.com/enca&HL=Market_MSNIS_Taglines 
>  Start enjoying all the benefits of MSN® Premium right now and get the 
> first two months FREE*.
> 
> 

Depends on what is the effect on checkpoint operation by spreading out 
the disk i/o.  If the checkpoints are going to take more time, then 
doing this optimization may not be good idea  for checkpoint during a 
shutdown. In other cases I would think it is ok if a checkpoint 
finishes in a reasonable amount of time.

thanks
-suresht