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 <[email protected]>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 Where Derby has been replaced by MySQL is when someone wanted a multi-user 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: [email protected] > > To: [email protected] > > > > Hi > > > > What is the significance of Derby in Hadoop Project. > > Why people are using Derby along with Hadoop > > > > Regards > > Saravana Kumar.J > >
