In this SQL Server tip, Arthur Fuller explains the effects of NULLs, and the different results obtained by inner and outer JOINs.

I need to form the equivalent of a Union Join in Oracle 8i, even though a Union Join doesn't appear to be supported in 8i. I might be able to manipulate a Full Outer Join to get the results I need ...

You can create an SQL view that contains the syntax of your query. You will use this view to create an outer join query. In the SQL QUERY TABLES window, select SAMPLE.EMPINFO and SAMPLE.SALARY from ...

The DBMS server will perform the join and return only the results of the join to the SAS software. This will provide a major performance enhancement for many of your programs that perform joins across ...