6. The system of claim 1 , wherein the class of the hierarchal classes further includes the attribute of including a classification type that is selected from pattern-based, keyword-based, rule-based, and classifier-based classification types.
6. The system of claim 1 , wherein the class of the hierarchal classes further includes the attribute of including a classification type that is selected from pattern-based, keyword-based, rule-based, and classifier-based classification types. 15. The system of claim 6 , wherein the semantic classification module is to: use the pattern-based classification to generate the semantic classification based on a pattern of values; use the keyword-based classification to generate the semantic classification based on a comparison of keywords to values of the column of the data to determine whether a value matches a keyword; use the rule-based classification to generate the semantic classification based on a classification of values of the column of the data based on pre-defined rules; and use the classifier-based classification to generate the semantic classification based on a classification of values of the column of the data based on previously determined classifications to determine a match.