If you specify this option, PROC SORT compares all variable values for each observation to those for the previous observation that was written to the output data set. If an exact match is found, the observation is not written to the output data set. You can remove all duplicates with this option by sorting on all variables. To see how the alphanumeric characters in each language will sort, refer to National Collating Sequences of Alphanumeric Characters . K specifies the amount of memory in kilobytes, where n is a real number.
M specifies the amount of memory in megabytes, where n is a real number.
G specifies the amount of memory in gigabytes, where n is a real number. Refer to the SAS documentation for your operating environment. This option can help improve sort performance by restricting the virtual memory paging that the operating environment controls. If PROC SORT needs more memory, it uses a temporary utility file. The BY variables and the observation numbers are called tags .