Re: Proposition fetch cursors

On Tue, 14 Jun 2011 20:49:48 +0800, Craig Ringer wrote:
> On 06/14/2011 04:30 PM, Radosław Smogura wrote:
>> Hello,
>>
>> I have proposition about one missing feature for cursors. Actually
>> there
>> is no support for fetching some data from cursor without moving it
>> (in
>> context of external applications). This could be nice if driver
>> could
>> fetch e.g. 100 rows, buffer it internally and then move cursor at
>> desired position in order to update data. I think this is known
>> approach
>> in databases.
>
> Interesting.
>
> Do you want this only for scrollable cursors? Or do you want/need to
> be able to "peek" ahead into the results of a non-scrollable cursor
> too?
>
> What's your use case?
>
> --
> Craig Ringer

Actually for "for update" cursors (so for all non-scrollable). With
scrollable I can move backward and forward simulating fetches, but for
update it's small pain, as in order to update n-th row (I doesn't know
at begin that this is n-th row) I should ask n-times to get this row,
moving forward one-by-one - adding network "overhead". With fetches I
can ask to fetch 100 rows from current position, process it on my side,
and then decide where to move cursor (eventually to update data).

Regards,
Radek