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From Ted Dunning <tdunn...@maprtech.com>
Subject Re: Derby with Hadoop --Why?
Date Wed, 10 Aug 2011 05:55:10 GMT
No.  He meant nothing of the kind.  The other explanations expanded on this.

This sounds like homework.  If so, I would recommend a bit of reading before
asking.

On Tue, Aug 9, 2011 at 10:37 PM, Saravana Kumar
<saravana.hadoop@gmail.com>wrote:

> Thanks For the Explanation but needs some clarity as well
>
> Do you mean to say all the Information required to run a map/reduce job is
> effectively stored in derby. It means hadoop(not Ecosystem) uses Derby?
>
> On Tue, Aug 9, 2011 at 5:52 PM, Michael Segel <michael_segel@hotmail.com
> >wrote:
>
> >
> > Derby?
> >
> > First a little history...
> > Derby started out long ago as Cloudscape. Cloudscape was bought by
> > Informix. Informix was bought by IBM. IBM didn't understand Cloudscape
> and
> > decided to open source the project under APL. Hence Derby was born.
> >
> > Derby is an excellent lightweight 100% java database. So when you have a
> > Java framework, using Derby makes a lot of sense. Derby is used to
> persist
> > some environment information and I believe its used in part of some of
> the
> > unit testing.
> >
> > Where Derby has been replaced by MySQL is when someone wanted a
> multi-user
> > database and they were more comfortable with MySQL than they were with
> > Derby. (Hint: Derby can be started as an embedded single user database,
> or
> > as a multi-user database by changing its invocation at startup. ;-)
> >
> > So I would guess the initial reason to go with Derby was that its
> released
> > under APL and there were no licensing issues. ;-)
> >
> >
> > > Date: Tue, 9 Aug 2011 15:17:35 +0530
> > > Subject: Derby with Hadoop --Why?
> > > From: saravana.hadoop@gmail.com
> > > To: general@hadoop.apache.org
> >  >
> > > Hi
> > >
> > > What is the significance of Derby in Hadoop Project.
> > > Why people are using Derby along with Hadoop
> > >
> > > Regards
> > > Saravana Kumar.J
> >
> >
>

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