Specify the number of rows from the data file to be scanned to determine the attributes of variables (columns) in the SAS data set. The attributes include type (such as numerical, character, and date) and length.Once the attributes are decided, they are applied to the entire data file. The length of character variables is a main concern among attributes. If there is any row after the number specified having larger length than the determined length of the variable, it will be truncated.Note : The value must be within the range specified in the square brackets, inclusive. Large values of this option can slow down the import process.