The AVERAGE RECORD SIZE option applies only to compact data sets. Records within compact data sets can vary in size. Typically, the maximum record size greatly exceeds the average record size. The AVERAGE RECORD SIZE option enables the user to specify the average size of the records. The DASDL compiler uses this value to compute the value of other attributes, such as BLOCKSIZE.

If the average record size is not specified, the average of the minimum and maximum record sizes is used.