Re: updatable cursors and ORDER BY

On Thu, May 10, 2018 at 12:55:23PM -0400, Tom Lane wrote:
> Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> writes:
> > I think that last part isn't actually written down anywhere. (It only
> > states the converse.) How about a clarification like this:
>
> > @@ -271,7 +271,10 @@ <title id="sql-declare-notes-title">Notes</title>
> > and not use grouping or <literal>ORDER BY</literal>). Cursors
> > that are not simply updatable might work, or might not, depending on plan
> > choice details; so in the worst case, an application might work in testing
> > - and then fail in production.
> > + and then fail in production. If <literal>FOR UPDATE</literal> is
> > + specified, then the cursor is guaranteed to be updatable, or the
> > + <command>DECLARE</command> command will error if an updatable cursor
> > + cannot be created for the supplied query.
> > </para>
>
> OK by me, except we don't usually use "error" as a verb. Either "fail"
> or "throw an error" would read better IMO. Or you could just stop with
> "guaranteed to be updatable"; I don't think the rest adds much.

I have done as you suggested and just used the first part; patch
attached and backpatched.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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