Re: another query optimization question

HI Tom.

> I got a little distracted by the bizarre actual-time values shown for
> some of the query steps:
>
>> -> Merge Join (cost=2451266.53..2655338.83 rows=13604393
>> width=8)
>> (actual time=82899.466..-2371037.726 rows=2091599 loops=1)
>
>> -> Sort (cost=2451169.10..2483246.47 rows=12830947
>> width=8)
>> (actual time=82891.076..-529619.213 rows=4187378 loops=1)
>
>> -> Hash IN Join (cost=507.32..439065.37
>> rows=12830947
>> width=8) (actual time=61.943..1874640.807 rows=4187378 loops=1)
>
> The hash-join total time is obviously wrong seeing that the total
> runtime is only about 100000 msec, and the negative values for the
> other
> two are even more obviously wrong.
>
> I recall that we saw similar symptoms once before, and I thought we'd
> fixed it, but I didn't find any relevant mentions in the CVS logs.
>
> What version are you running, exactly? Could you repeat the EXPLAIN
> with client_min_messages set to 'debug2', and see if you see any
> messages about InstrStartTimer or InstrStopNode?
>

7.4.1, build from sourcecode. Running on MacOS X Server 10.3.2, dual G5
with 3.5 GB RAM

I have set client_min_messages in postgresql.conf to debug2 but i see
nothing. Is this going to the normal logfile? Must i activate anything
else?

regards David