SAS/ACCESS 9.2 for Relational Databases: Reference, Fourth Edition

492 How WHERE Clauses Restrict Autopartitioning 4 Chapter 16If a nullable column is selected for autopartitioning, the SQL statementORIS NULL is appended at the end of the SQL code that is generated forone read thread. This ensures that any possible NULL values are returned in theresult set.How WHERE Clauses Restrict AutopartitioningAutopartitioning does not select a column to be the partitioning column if it appearsin a SAS WHERE clause. For example, this DATA step cannot use a threaded read toretrieve the data because all numeric columns in the table (see the table definition in“Using DBSLICE=” on page 492) are in the WHERE clause:data work.locemp;set trlib.MYEMPS;where EMPNUM