In SAS^® 9.2 Phase I, PROC SQL generates a Cartesian product when you join a SAS table and a database management system (DBMS) table. When this happens, the following note is added to the SAS log:

NOTE: The execution of this query involves performing one or more Cartesian product
      joins that can not be optimized.

This problem happens if you include a CALCULATED component in a WHERE clause.

If PROC SQL generates a Cartesian product, one or more of the following issues can occur:

• All rows that are retrieved from DBMS tables are used in the join.
• Join queries run for excessively long periods of time.
• Temporary disk space can be exhausted, resulting in out-of-resource errors.
• A results set can be generated that is much larger than expected.

To fix this problem, you must apply the second maintenance release for SAS 9.2 (TS2M2).

Operating System and Release Information