I apologize my statement about NULL being used to join is incorrect as both Vitalii and Gustavo have both pointed out in their respective replies.
----------------- Phillip Couto > On Jan 19, 2017, at 08:30, Vitalii Tymchyshyn <v...@tym.im> wrote: > > > Hi. > > In SQL "null == any value" resolves to false, so optimizer can safely skip > nulls from either side if any for the inner join. > > Best regards, Vitalii Tymchyshyn > > NULL is still a value that may be paired with a NULL in a.a > > The only optimization I could see is if the a.a column has NOT NULL defined > while b.b does not have NOT NULL defined. > > Not sure if it is all that common. Curious what if you put b.b IS NOT NULL in > the WHERE statement? > > ----------------- > Phillip Couto > > > >
