Is there a reason MySQL doesn't support FULL OUTER JOINS?

Question

Is there a reason MySQL doesn\'t support FULL OUTER JOINS? I\'ve tried full outer join syntax in mysql many times and it never worked, just found out its not supported by my

Answer 1

From High Performance MySQL:

At the moment, MySQL’s join execution strategy is simple: it treats every join as a nested-loop join. A FULL OUTER JOIN can’t be executed with nested loops and backtracking as soon as a table with no matching rows is found, because it might begin with a table that has no matching rows.This explains why MySQL doesn’t support FULL OUTER JOIN