Before Oracle 10g, the only way to perform a full outer join was to use two queries -- one that does a right outer
join and the other that does a left outer join. And then use the UNION or UNION ALL operator between the two result sets to combine them into a full outer join.
Oracle 10g introduced the the ANSI-compliant FULL OUTER JOIN clause which makes the above unnecessary.
Dig deeper on Oracle and SQL
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.