madlib/madlib — pull request #184 by aojwang (2012-07-27 12:18:10+00:00)
Title: Performance Improvement on Tree Growing Engine

Jira: MADLIB-607
This file implements the tree growing engine for C4.5 and RF, which includes training, classification, scoring and displaying.
There are few changes on classification/scoring/displaying/clean. Most of changes are in training process.
The steps of training:
0. Encoding the training table.
1. Generating ACC (a group by statement).
2. Generating ACS and calculating SCVs and finding the best SCVs (in a single SQL statement)
3. creating the child nodes(a sigle SQL statement)
4. recursive the step 1 to step 3 until we met the stop condition.

Details are available at this http://confluence.greenplum.com/x/WITaAg.