Re: BUG #1916: selection criteria from one outer join

I agree that it looks like "overenthusiastic propagation
of implied equalities." (Nicely put.) I haven't tested
whether this fails in any other version (we've moved all
our instances to 8.1beta2 to pound it the best we can),
but I see that Klint Gore has reported the test case fails
in 7.4.7 and 8.0.0.

Any idea on when a fix might be available, or what
conditions must exist in a query for this failure to occur?
If this is too big to fix in 8.1, we would want to try to
identify vulnerable queries proactively, to work around
it somehow.

-Kevin


>>> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> 09/27/05 11:34 PM >>>
"Kevin Grittner" <kevin(dot)grittner(at)wicourts(dot)gov> writes:
> Obviously, adding an outer join to a query which is already returning rows
> should never reduce the number of rows returned.

I think this is a case of overenthusiastic propagation of implied
equalities. Do you know offhand if it fails in 8.0.* or earlier
branches?

regards, tom lane