declare 
    cm_accuracy number;
begin
    execute immediate 'drop table iris_confusion_matrix';
    exception
        when others then
            if sqlcode = -942 then null;
            else
                dbms_output.put_line('ERROR making evaluations');
                dbms_output.put_line('Reason: Unable to delete previous table containing confusion matrix.');
                dbms_output.put_line('Message: ' || sqlerrm);
                dbms_output.put_line('--------------------------------------------------');
            end if;

    begin
        dbms_data_mining.compute_confusion_matrix(
            accuracy => cm_accuracy,
            apply_result_table_name => 'iris_predictions',
            target_table_name => 'v_iris_test',
            case_id_column_name => 'id',
            target_column_name => 'species',
            confusion_matrix_table_name => 'iris_confusion_matrix',
            score_column_name => 'prediction',
            score_criterion_column_name => 'probability',
            cost_matrix_table_name => null,
            apply_result_schema_name => null,
            target_schema_name => null,
            score_criterion_type => 'PROBABILITY'
        );
        dbms_output.put_line('Accuracy: ' || round(cm_accuracy * 100, 2) || '%');
    exception
        when others then
            dbms_output.put_line('ERROR making evaluations');
            dbms_output.put_line('Reason: Unable to create a confusion matrix table.');
            dbms_output.put_line('Message: ' || sqlerrm);
            dbms_output.put_line('--------------------------------------------------');
    end;
end;
/