I may have missed this but have you tuned your postgresql
configuration ?
8.2 tuning guidelines are significantly different than 7.3
Dave
On 1-Apr-07, at 1:51 PM, Xiaoning Ding wrote:
> I repeated the test again. It took 0.92 second under 8.2.3.
> I checked system load using top and ps. There is no other
> active processes.
>
> Xiaoning
>
> Ron Mayer wrote:
>> Xiaoning Ding wrote:
>>> Postgresql is 7.3.18. [...]
>>> 1 process takes 0.65 second to finish.
>>> I update PG to 8.2.3. The results are [...] now.
>>> 1 process : 0.94 second
>> You sure about your test environment? Anything else
>> running at the same time, perhaps?
>> I'm a bit surprised that 8.2.3 would be 40% slower than 7.3.18
>> even in the single process case.
>> ---------------------------(end of
>> broadcast)---------------------------
>> TIP 2: Don't 'kill -9' the postmaster
>
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match