drop view if exists v_corpus_group_class;
drop table if exists hotspot_sentence;
drop table if exists hotspot_instance;
drop table if exists hotspot;
drop table if exists feature_parchd;
drop table if exists feature_rank;
drop table if exists feature_eval;
drop table if exists tfidf_doclength; 
drop table if exists cv_fold;
drop table if exists cv_fold_instance;
drop table if exists cv_best_svm;
drop table if exists classifier_instance_eval_prob;
drop table if exists classifier_instance_eval;
drop table if exists classifier_eval_svm;
drop table if exists classifier_eval_semil;
drop table if exists classifier_eval_ir;
drop table if exists classifier_eval;
DROP TABLE IF EXISTS kernel_eval;
DROP TABLE IF EXISTS kernel_eval_instance;
drop table if exists corpus_label;
drop table if exists corpus_doc;
