Currently, SAS/ACCESS® Interface to DB2 on a z/OS system might not efficiently handle a PROC SQL query that contains 32 DB2 tables.
Instead of the query being passed to DB2, the data is retrieved from all of the DB2 tables and SAS handles the processing of the query. As a result, the query might take longer than it would have had DB2 done the processing.
If your query contains 33 or more DB2 tables, an error similar to the following might occur:
ERROR: DBMS table open failed. The maximum number of DBMS opens for this engine (32) has been reached.
The only way to work around this issue is to divide the query into multiple queries.