If you use PROC SORT, the sorting will be done on one SAS dataset on your SAS server.
If you use SQL, the SORT may be done on the Oracle server, depending on a the complexity of the syntax and whether or not other filter or query options (like functions in the expression builder) can be translated into Oracle's flavor of SQL or not. (SAS tries to resolve the syntax into something that Oracle can do and just get the results back at the end.).
Personally, I do it both places. If all I need is a sort, I do it in the SORT task; if I am doing other transformations, I'll let SQL do it (the latter case is more common). If I've lot lots of data (hundreds of thousands of records), then I am more thoughtful in my choice (and read the SAS/Access for Oracle manual).
Doc Muhlbaier
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