1) You have to use the proc sql pass-through form of connection to Oracle
connect to oracle as mycon (user=testuser password=testpass preserve_comments);
from connection to mycon
(select /* +indx(empid) all_rows */
count(*) from employees);
In the Oracle connection string, there is a required option
from "help" for SAS/ACCESS for Oracle, pass-through facility
enables you to pass additional information (called hints) to Oracle for processing. These hints might direct the Oracle query optimizer to choose the best processing method based on your hint.
You specify PRESERVE_COMMENTS as an argument in the CONNECT statement. Then you specify the hints in the CONNECTION TO component's Oracle SQL query. The hints are entered as comments in the SQL query and are passed to and processed by Oracle.