On Wed, May 19, 2010 at 1:38 AM, A. Kretschmer
<andreas(dot)kretschmer(at)schollglas(dot)com> wrote:
> In response to Guillaume Lelarge :
>> > This is the default behavior I want. However, I am not sure whether this is always guarantee? Or shall I explicitly make the query in the following form?
>>
>> An you're right. It's not guaranted. The only guaranted way is to use
>> ORDER BY your_column.
>
> ACK. One reason is the new feature 'synchronised scan' sind 8.3. It's a
> big performance boost, but engendered unsorted results. (if there is not
> the ORDER BY - statement)
Just for reference I once had three separate oracle dbas saying my pg
server was broken because group by came out in random order (due to
hash aggregates).