flex89 saidInner join, left join, right join, outer join, or implicit inner join?
Discuss; because a client of mine insists inner joins are faster and I need to know I'm not crazy for knowing otherwise
In a classic inner join all that is returned is the data matched in both tables by your where clause. I suspect what your client is seeing is perhaps an outer join (eitehr left or right) where there are huge tables. Keep in mind that for a left outer join where Table A contains 20 million rows, all 20 million are going to be returned.
The execution time of the query may not actually be longer, but the return and release of database resources will be huge.
In all liklihood a well constructed data model and clean data will return much quicker in the inner join. But in poorly designed data models and with odd queries one never knows.