Differentiate between natural join and outer join?
Natural join is a binary operator which is written as (R * S) where as R and S are relations. The output of the natural join is the set of all merge of tuples in R and S that are equal on their general attribute names. In this just one column out of columns having similar name attributes is retained.
An Outer join holds those tuples and additionally a few tuples formed through extending an unmatched tuple in one of the operands through "fill" values for each of the attributes of the other operand.