commit 1c65e8569e1e54442cd98a724d7fb9d132994787
author jarodwen@gmail.com <jarodwen@gmail.com@123451ca-8445-de46-9d55-352943316053> Mon Jan 24 19:26:42 2011 +0000
committer jarodwen@gmail.com <jarodwen@gmail.com@123451ca-8445-de46-9d55-352943316053> Mon Jan 24 19:26:42 2011 +0000
tree 47349fc59ad23c712b9cac44441f9f7d09ce29ea
parent d6feea790681de7308b911cb8dd16366d10035df

Added external hash group operator. Main changes include: 
- added external hash group operator and its helper hash table class, and test cases; 
- modified aggregator factories to support external group operator;
- added some aggregators (min/max, sum);
- added a plain file writer to output plain text onto disk.

git-svn-id: https://hyracks.googlecode.com/svn/branches/hyracks_spilling_groupby@301 123451ca-8445-de46-9d55-352943316053