Re: "ORDER BY" clause prevents "UPDATE WHERE CURRENT OF"

> [ dept of second thoughts... ]  Actually, given that he said FOR UPDATE,
> the plan should be propagating the tuple identity through to top level
> so that execMain can do its thing.  So in principle we could probably
> get the information without widespread changes.  This would fit
> reasonably well with the spec's requirements too --- any but trivial
> cursors are not deemed updatable unless you say FOR UPDATE.  But it
> would mean two completely independent implementations within
> execCurrent.c...

What's particularly unfortunate is Greg's comment that this would work
if the planner chose an index scan.  Had I defined an index on the
columns in question, my code might have worked and been deployed to
production - and then broken if the planner changed its mind and
decided to use a seqscan after all.

ISTM any cursor that's going to be updated should specify WHERE UPDATE
in the query, but maybe that's not a hard requirement as of now.

...Robert