Thomas Lockhart <lockhart@alumni.caltech.edu> writes:
> But it is possible, under many circumstances, for query optimization to
> be a benefit for a many-table query. The docs indicate that explicit
> join syntax bypasses that, even for inner joins, so you may find that
> this syntax is a net loss in performance depending on the query and your
> choice of table order.
> Presumably we will be interested in making these two forms of inner join
> equivalent in behavior in a future release. Tom, what are the
> impediments we might encounter in doing this?
I don't think there are any real technical problems in the way; it's
simply an implementation choice not to treat INNER JOIN the same as an
implicit join list. I did it that way in 7.1 mainly as a flyer, to see
how many people would think it's a feature vs. how many think it's a
bug. The votes aren't all in yet, but here we have Mike apparently
pretty pleased with it, while I recall at least one other person who
was not happy with the 7.1 behavior.
regards, tom lane