Re: Status of issue 4593

Jeff Davis <pgsql@j-davis.com> writes:
> On Mon, 2009-01-05 at 15:42 -0500, Tom Lane wrote:
>> The only way to avoid this would be to lock before the sort, which could
>> have the effect of locking more rows than are returned (if you also use
>> LIMIT);

> How would that work in the case of an index scan sort?

It wouldn't, which is one of the problems with doing it any other way...

I don't think there's a bug here, at least not in the sense that it
isn't Operating As Designed.  But it does seem like we could do with
some more/better documentation about exactly how FOR UPDATE works.
The sequence of operations is evidently a bit more user-visible than
I'd realized.

            regards, tom lane