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From Mike Matrigali <mikem_...@sbcglobal.net>
Subject Re: [PATCH] Derby 218 - Add relaxed durability option
Date Mon, 02 May 2005 15:43:33 GMT
suresh, you have done a lot of work in this area could you review
the patch and post your comments?

Sunitha Kambhampati wrote:
> A little background: Sometime earlier on the list, Dan posted a fix to 
> make derby go faster with relaxed durability with some flags.  The post 
> is at 
> http://article.gmane.org/gmane.comp.apache.db.derby.user/681/match=relaxed+durability

> This mode is very useful for unit testing or at development time when 
> recoverability is not required.
> Basically in this mode, syncs are disabled for logs, data writes at 
> checkpoint, page allocation when file is grown; - what this means is 
> that data is not flushed all the way to the disk and in most cases i/o 
> cost is not involved. Note,  code already exists in Derby to do this.
> So for Derby 218, This  patch addresses the following requirements:  1) 
> Have a single property to enable this relaxed durability mode, so it is 
> easy for users  to enable it.
> 2) Print message to derby.log that this mode is enabled
> 3) A way to report boot errors that may be because of this option being 
> enabled. What this maps to is - have a marker to recognize that database 
> was booted in this mode, and then on subsequent boot; if errors happen 
> during recovery - report a message that it could have happened because 
> of this mode being set.
 > ... deleted ...

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