CDA L2 compared to L1 is difficult, but not to the test of fear Oh, CDA L2 assessment points in addition to mastering the skills required by the L1, should also master advanced data processing techniques and machine learning methods (feature engineering, Bayesian, linear regression, decision trees, neural networks and deep learning, support vector machines, integration methods, model evaluation, cluster analysis, association rules, sequence patterns, etc.) and visualization techniques. Master Hadoop cluster construction, can be proposed for different business big data architecture solution ideas.CDA L2 in addition to the basic theory questions more practical operation of the assessment points, the proportion of points is quite high, rely on self-study book is more strenuous, it is recommended to apply for a CDA data analysts related coaching courses, for the preparation of the exam will be more helpful.