Re: 7.2 is slow?

Tatsuo Ishii <t-ishii@sra.co.jp>

From: Tatsuo Ishii <t-ishii@sra.co.jp>
To: mathijs@ilse.nl
Cc: hannu@tm.ee, bpalmer@crimelabs.net, pgsql-hackers@postgresql.org
Date: 2001-12-17T14:12:53Z
Lists: pgsql-hackers

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> > How did you test ?
> > 
> > I could do the same test on Dual Pentium III / 800 w/1024 MB
> > with IBM 45 G/7200 IDE disk.
> > 
> > So we could compare different platforms as well :)
> 
> I could do some testing on a Sun 450 / 4x400 MHz / 4 GB, if that's helpful.
> 
> Cheers,
> 
> Mathijs
> 

> I'll have 4 way and 8 way xeon boxes tues evening that I can test this
> against (though I won't get to test till wed unless I don't sleep)
>
> - Brandon

Thanks to everyone. Here are the methods I used for testings including
generating graphs (actually very simple).

(1) Tweak postgresql.conf to allow large concurrent users. I tested up
    to 1024 on AIX, but for the comparison I think testing up to 128
    users is enough. Here are example settings:

    max_connections = 128
    shared_buffers = 4096
    deadlock_timeout = 100000

    You might want to tweak wal_sync_method to get the best
    performance. However this should not affect the comparison between
    7.1 and 7.2.

(2) Run:

    sh bench.sh

    It will invoke pgbench for various concurrent users. So you need
    to install pgbench beforehand (it's in contrib/pgbench. Just type
    make install there to install pgbench).

    This will take while.

(3) (2) will generate a file named "bench.data". The file have rows
        where the first column is the number of concurrent users and
        second one is the tps. Rename it to bench-7.2.data.

(4) Do (1) and (2) for PostgreSQL 7.1 and rename bench.data to
    bench-7.1.data.

(5) Run plot.sh to see the result graph. Note that plot.sh requires
    gnuplot.
---
Tatsuo Ishii