On 01/23/2012 04:34 PM, Alban Hertroys wrote:
> On 23 January 2012 14:48, Sim Zacks <sim@compulab.co.il> wrote:
>>> In my tests, if the joined rows are sorted it always updates with the
>>> first row. Does anyone have any other experiences, or should I be
>>> concerned that at some point it will behave differently?
>>
>> I checked my tests again. It always uses the last one, not the first one.
>>
>> Sim
>
> I expect that your records get updated multiple times too.
>
> Perhaps you can use DISTINCT ON in your from-based UPDATE?
>
The select in the from statement (i.e. update.. from (select...) )
returns 2739 records. It updates 617 records.
When I run the update it returns "617 rows affected"
So I'm guessing it is not multiple updates.
Sim