On Wed, Oct 7, 2009 at 4:20 PM, Marko Tiikkaja
<marko.tiikkaja@cs.helsinki.fi> wrote:
> Jaime Casanova wrote:
>>
>> On Wed, Oct 7, 2009 at 4:08 PM, Marko Tiikkaja
>> <marko.tiikkaja@cs.helsinki.fi> wrote:
>>>
>>> 1) WITH t AS
>>> (UPDATE foo SET bar = bar+1 RETURNING *)
>>> SELECT * FROM t LIMIT 1;
>>>
>>> What's problematic here is that only 1 row is read from the CTE, meaning
>>> also that only one row is updated which, at least how I see it, is not
>>> what we want. The CTE should only store one row and return that after
>>> it has completely processed the UPDATE statement.
>>>
>>
>> i'm talking from my ignorance... but AFAIU this should process the
>> whole UPDATE and then form a WorkTable with the results...
>> what the select reads from that results is another thing...
>>
>
> Right. This is exactly what I'm trying to do, except I think we could
> easily optimize this case and store only the first processed row inside
> the CTE.
>
why? we don't should be thinking in optimizations in this phase
--
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157