Re: Modify the DECLARE CURSOR command tag depending on the scrollable flag

From: Boszormenyi Zoltan <zb(at)cybertec(dot)at>
To: Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Michael Meskes <meskes(at)postgresql(dot)org>, Noah Misch <noah(at)leadboat(dot)com>, Peter Eisentraut <peter_e(at)gmx(dot)net>, Robert Haas <robertmhaas(at)gmail(dot)com>, PG Hackers <pgsql-hackers(at)postgresql(dot)org>, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com>, Bruce Momjian <bruce(at)momjian(dot)us>, Hans-Jürgen Schönig <hs(at)cybertec(dot)at>
Subject: Re: Modify the DECLARE CURSOR command tag depending on the scrollable flag
Date: 2013-11-28 07:47:29
Message-ID: 5296F511.1090304@cybertec.at
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

2013-11-27 20:49 keltezéssel, Alvaro Herrera írta:
> Boszormenyi Zoltan escribió:
>
>> If you consider all these:
>>
>> - certain combinations of query and DECLARE stmt flags fail;
>> - adding NO SCROLL is breaking backward compatibility;
>> - the readahead code has to really know whether the cursor is
>> scrollable so it can behave just like the server;
>>
>> then returning the SCROLL / NO SCROLL flag in the command tag is
>> not a bad solution in my view. In fact, this was the only workable
>> solution I could come up with to make it work reliably when neither
>> SCROLL nor NO SCROLL is specified by the application.
> Would it work to have a function of some sort to which you give a cursor
> name and it returns whether it is scrollable or not?

D'oh. Yes, that would also work. Thanks for the idea. :-)
I will implement it and adapt my remaining patches.

Best regards,
Zoltán Böszörményi

--
----------------------------------
Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt, Austria
Web: http://www.postgresql-support.de
http://www.postgresql.at/

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Boszormenyi Zoltan 2013-11-28 08:04:17 Re: Modify the DECLARE CURSOR command tag depending on the scrollable flag
Previous Message Pavel Stehule 2013-11-28 07:44:23 Re: Re: [BUGS] BUG #7873: pg_restore --clean tries to drop tables that don't exist