Please, please, please don't perform your JOINs with comma-separated items in the FROM clause. As soon as you need also to do an OUTER JOIN, you're going to get

Please, please, please don't perform your JOINs with comma-separated items in the FROM clause. As soon as you need also to do an OUTER JOIN, you're going to get unexpected results. Per the SQL spec, explicit JOIN-style syntax binds more tightly than FROM-list elements, which can not only constrain the query planner in the choices it can make, but can actually yield a different result.