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From Mike Matrigali <mikem_...@sbcglobal.net>
Subject Re: Quick question... on use with "Ram Drives" or FOBs...
Date Wed, 17 Aug 2005 00:53:16 GMT
I am not exactly sure of the terminology, but some sort of RAM drive for
the log device makes the entire autocommit log sync issue go away - and
since we garbage collect the log then we don't need that big of a device.

We
have a machine here which has a relatively small memory backed ram cache
in front of a real hard drive and it does the trick also, it is just a
feature of the controller - we didn't even know it was there until our
autocommit performance numbers looked an order of magnitude or more better.

It does not
have to be very big as it just needs to cache it in a safe manner until
a big write can take it all to the real disk - I think it is only 512 bytes.

In memory database will have other benefits, but just putting the derby
db on an memory disk may give an application all the performance it needs.

Michael J. Segel wrote:

> Hi,
> 
> Quick question...
> 
> Has anyone tried using Derby/Cloudscape with the data being written to one of 
> those 512MB FOBs instead of a hard drive?
> 
> Got in to a discussion over a beer last night regarding "in memory" databases 
> vs solid state drives vs those FOBs that now have over a GB of storage.
> 
> Trying to see if we can improve performance by a simple hardware change....
> 
> Thoughts?
> 

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