Accessing a relatively small number of the total number of defined columns results in a huge increase in performance compared to a RWN. However, reading a complete CWN will take slightly longer than reading a RWN due to the overhead introduced by the type checking and compression mechanisms and because the data is not stored sequentially on disk. The performance increase with a CWN will most clearly show up when using PAW, where one typically histograms one column with cuts on a few other columns. The advantages of having different data types and data compression generally outweighs the performance penalty incurred when reading a complete CWN.