Well, for once Hive uses Derby by default as its metastore. What make you think that Hadoop project is using derby?
Also, this question seems to belong to common-dev@ (Cc'ed) raher then general@ (Bcc'ed) Cos On Wed, Aug 10, 2011 at 11:07AM, Saravana Kumar 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_se...@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 Where Derby has been replaced by MySQL is when someone wanted a multi-user 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.had...@gmail.com > > > To: gene...@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 > > > >
