Question

What is the default type of join that Oracle12c will perform?

1) Inner join
2) Outer join
3) Cross join
4) Self join

Answer 1

The default join type in Oracle12c when not specified is an inner join, which returns rows when there is at least one match found in both tables.

Step-by-step explanation:

The default type of join that Oracle12c will perform is an inner join. When you write a query that includes a join clause without specifying the type of join, Oracle will execute an inner join. An inner join retrieves data that has matching values in both tables involved in the join. It is the most commonly used type of join because it returns rows only when there is at least one match in both tables. This contrasts with an outer join, which returns all rows from one table, and the matched rows from the other table, a cross join, which produces a Cartesian product of all rows in the tables, and a self join, which is a join of a table to itself.