Hi Juan Casero,
I've found that serial query clients are best served by PostgreSQL
running on fast single or dual core processors, ( such as the Athlon
FX60 ) rather than expensive n-way systems. I was orginally using an
8-way Xeon computer for a similar serial throughput problem. and i
wasn't supprised to find that at least 6 of the 8 processors were idle.
The point is, for this type client, you are better off spending the
money on the fastest single or dual core processors than a multiway box.
Anthony.
Juan Casero (FL FLC) wrote:
Greetings -
I
am testing a Sun Microsystems Sun Fire T2000 demo server at our
company. I want to know if anyone here has any experience with this
hardware and postgresql 8.1.3. I installed the copy of postgresql
8.1.3 from blastwave.org onto this demo box and loaded our production
database into it. This box has a single Ultrasparc T1 cpu with six
execution piplelines that can each handle 4 threads. With the Unix top
utility the postgresql server appears to bounce around between the
available threads on the system. For example I run a single large
query and I can see the postgresql server sometimes running on cpu/0,
other times on cpu/1, cpu/3,....etc up to cpu/23. However, never is
the load for the postgres server reported to be higher than 4.16%. I
did the math and 4.16% x 24 threads = 98.84% cpu load. So I wonder if
the Solaris 10 kernel is somehow throttling the processes so that any
single virtual processor can do no more than 4.16% load. We got this
server last week and I was able to install it in our rack just
yesterday. Now I need to see how I can optimize the postgresql server
to work on this box. Does anyone have any suggestions? I know the
postgresql server is not smp aware but I believe parts of it are. In
particular the buffer manager is supposed to scale the performance
almost linearly with the number of cpu's (including virtual ones). I
don't know however, if I need to recompile the postgresql server myself
to get those benefits. I am using the version of postgresql 8.1.3
that is available on blastwave.org. I am also working with the 64 bit
version of the database server. This machine has over 8GB of ram so I
was thinking of using the 64 bit version of the postgresql server so I
can access ram beyong the 4gb limit imposed by 32 bit addressing. Any
help or recommendations for performance tweaking of postgresql is very
much appreciated.
Thanks,
Juan
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