tag sort in proc sort

[GN0001]

Hello team,

Can someone explain about tag sort? Different definitions in search so I am not sure what exactly it is doing.

Thanks,

blueblue

[Kurt_Bremser · Accepted solution]

What's hard to understand here:

TAGSORT

stores only the BY variables and the observation numbers in temporary files. The BY variables and the observation numbers are called tags. At the completion of the sorting process, PROC SORT uses the tags to retrieve records from the input data set in sorted order.

Note: The utility file created is much smaller than it would be if the TAGSORT option were not specified.

[ChrisNZ]

This option tells SAS to only read the BY variables when sorting.

The other variables are added as a second step.

Pros: Small utility file as few variables are moved around

Cons: Fetching the other variables when the sort is complete can take a long time