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

Optimizing Your SQL Usage 4 Passing Joins to the DBMS 433 Netezza3 ODBC3 OLE DB3 Oracle3 Sybase3 Sybase IQ3 TeradataPassing Joins to the DBMSWhen you perform a join across SAS/ACCESS librefs in a single DBMS, PROC SQLcan often pass the join to the DBMS for processing. Before implementing a join, PROCSQL checks to see whether the DBMS can process the join. A comparison is made usingthe SAS/ACCESS LIBNAME statement for the librefs. Certain criteria must be met forthe join to proceed. Select your DBMS to see the criteria that it requires before PROCSQL can pass the join.3 Aster nCluster3 DB2 Under UNIX and PC Hosts3 DB2 Under z/OS3 Greenplum3 HP Neoview3 Informix3 MySQL3 Netezza3 ODBC3 OLE DB3 Oracle3 Sybase3 Sybase IQ3 TeradataIf it is able, PROC SQL passes the join to the DBMS. The DBMS then performs thejoin and returns only the results to SAS. PROC SQL processes the join if the DBMScannot.These types of joins are eligible for passing to the DBMS.3 For all DBMSs, inner joins between two or more tables.3 For DBMSs that support ANSI outer join syntax, outer joins between two or moreDBMS tables.3 For ODBC and Microsoft SQL Server, outer joins between two or more tables.However, the outer joins must not be mixed with inner joins in a query.3 For such DBMSs as Informix, Oracle, and Sybase that support nonstandard outerjoin syntax, outer joins between two or more tables with these restrictions:Full outer joins are not supported.Only a comparison operator is allowed in an ON clause. For Sybase, the onlyvalid comparison operator is ’=’.For Oracle and Sybase, both operands in an ON clause must reference a columnname. A literal operand cannot be passed to the DBMS. Because theseDBMSs do not support this, all ON clauses are transformed into WHERE