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* Re: updatable cursors and ORDER BY
@ 2018-06-12 00:44 Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
2018-06-12 02:59 ` Re: updatable cursors and ORDER BY Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 1 reply; 2+ messages in thread
From: Peter Eisentraut @ 2018-06-12 00:44 UTC (permalink / raw)
To: Bruce Momjian <bruce@momjian.us>; Tom Lane <tgl@sss.pgh.pa.us>; +Cc: pgsql-docs
On 5/28/18 13:17, Bruce Momjian wrote:
> On Thu, May 10, 2018 at 12:55:23PM -0400, Tom Lane wrote:
>> Peter Eisentraut <peter.eisentraut@2ndquadrant.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.
I think we should still add the second part, because it currently
doesn't say anything about that a cursor declaration might fail if an
updatable cursor cannot be created.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: updatable cursors and ORDER BY
2018-06-12 00:44 Re: updatable cursors and ORDER BY Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
@ 2018-06-12 02:59 ` Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 0 replies; 2+ messages in thread
From: Tom Lane @ 2018-06-12 02:59 UTC (permalink / raw)
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>; +Cc: Bruce Momjian <bruce@momjian.us>; pgsql-docs
Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
> I think we should still add the second part, because it currently
> doesn't say anything about that a cursor declaration might fail if an
> updatable cursor cannot be created.
I still think it wouldn't add anything. Any other error in the command
would cause the cursor declaration to fail, too.
regards, tom lane
^ permalink raw reply [nested|flat] 2+ messages in thread
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2018-06-12 00:44 Re: updatable cursors and ORDER BY Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
2018-06-12 02:59 ` Tom Lane <tgl@sss.pgh.pa.us>
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