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From Oystein.Grov...@Sun.COM (Øystein Grøvlen)
Subject Re: [jira] Commented: (DERBY-239) Need a online backup feature that does not block update operations when online backup is in progress.
Date Mon, 31 Oct 2005 18:58:47 GMT
>>>>> "MM" == Mike Matrigali <mikem_app@sbcglobal.net> writes:
    MM> Yes this is probably incorrect in a number of places.  There currently
    MM> is only one segment.  The segment number was added in the beginning so
    MM> that if we ever had to  do data partitioning ourselves we had a chance
    MM> to

    MM> add it without an ugly upgrade.  But as you are seeing over time some
    MM> hard coding has happened and if we ever really want another segment it
    MM> will have to be cleaned up.

    MM> My opinion is that the OS can do better data partitioning then we can so
    MM> I don't think it is very useful to add that feature.

I agree that the OS often can do a better job with data partitioning
but that often requires expensive storage systems (e.g., RAID).  

I think that many applications would perform better if it was possible
to put tables and indexes on different disks.

Also, Derby does not give the OS much opportunity to optimize IO as
long as it does not allow parallel disk accesses to a table.


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