7.00.02 - Forest_Drive - Aster Analytics

Teradata Aster® Analytics Foundation User GuideUpdate 2

Aster Analytics
Release Number
Release Date
September 2017
Content Type
Programming Reference
User Guide
Publication ID
English (United States)

The Forest_Drive function uses a training data set to generate a predictive model. You can input the model to the Forest_Predict function, which uses it to make predictions.

The size of each individual decision tree generated by the Forest_Drive function must be less than 32 MB. The factors that affect the size of a decision tree are the depth of the tree, the number of categorical inputs, the number of numerical inputs, and the number of surrogates. If the size of a decision tree exceeds 32 MB, the function issues an error message. Therefore, control the factors in the input data that increase the size of decision trees.

Aster Analytics provides a tree_size_estimator function that you can use to estimate maximum values for the arguments TreeSize and NumTrees, based on the cluster configuration and the number of predictor variables. The syntax is:

SELECT * FROM tree_size_estimator
  (ON inputtable NumericInputs ('predictor' [,…]));

The query results includes a row_count column. The average value of this column is the recommended maximum value for the argument NumTrees.