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

Boszormenyi Zoltan <zb@cybertec.at> writes:
> 2013-11-23 22:01 keltez�ssel, Tom Lane �rta:
>> Boszormenyi Zoltan <zb@cybertec.at> writes:
>>> Attached is the patch that modified the command tag returned by
>>> the DECLARE CURSOR command. It returns "DECLARE SCROLL CURSOR"
>>> or "DECLARE NO SCROLL CURSOR" depending on the cursor's
>>> scrollable flag that can be determined internally even if neither is
>>> asked explicitly.

>> This does not strike me as an acceptable change.  It will break any code
>> that's expecting the existing command tag, for little or no benefit
>> to most applications.  Even if backwards compatibility were of no concern,
>> I'm not convinced it's a good thing to expose the backend's internal
>> choices about query plans used for cursors, which is what this is
>> basically doing.

> I saw code in the backend allowing a cursor to be scrollable, although
> it was not declared as such. How about ripping that out?

That also fails the unnecessary-backwards-compatibility-break test.
        regards, tom lane