From: Boyd E. Hemphill [mailto:bhemphill@stripped]
> My boss says that if you do a select statement against a table the
> result set always comes back in the same order. I say that this is a
> myth and that the result is random, except when some ordering is
> specified in the SQL statement.
> Who is right? Is this behavior specified by ANSI or ISO?
From what I understand (as I've heard this explained a half dozen times by different
people), the results are returned in the order they appear on disk. This can change via
any number of factors (such as a disk defrag), though, so you should never rely on
getting results back in the same order every time if you're not using an ORDER BY clause.
For the most part, though, results /will/ appear to come back in the same order. I imagine
that's what your boss is talking about. It's definitely not to be relied on, though.
If this is documented online, I've yet to see it (though I haven't exactly gone looking
for it). Someone else may have a more accurate description of the way it's done, though.
Smarter Living, Inc.
phone (617) 886-5539