Re: Re[4]: Postgres is too slow?

From: "Alex Pilosov" <alex(at)pilosoft(dot)com>

> On Fri, 22 Jun 2001, Paul wrote:

> > # time dd if=/dev/hda3 of=/dev/null bs=64k count=10000
> > 10000+0 records in
> > 10000+0 records out
> >
> > real 3m33.731s
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > user 0m0.020s
> > sys 2m37.960s
>
> Whoa! Your drive is only capable of 3M/s (640M/213 sec) transfer! Your
> data set is 500K*200 bytes=100M. No surprise your queries take 30 seconds
> to run, since its exactly how much it'd take to transfer 100M of data from
> your drive.

Possibly, but my tests are saturating CPU anyway (granted only a 400MHz one)
even with the whole dataset cached.

$ vmstat 10
procs memory swap io system
cpu
r b w swpd free buff cache si so bi bo in cs us sy
id
0 0 0 0 29692 80908 86312 0 0 0 2 24 56 2 0
3
1 0 0 0 27712 80908 86312 0 0 0 43 112 26 88 5
7
1 0 0 0 27528 80908 86312 0 0 0 301 127 30 94 6
0
1 0 0 0 4380 80952 109400 0 0 0 650 153 32 78 22
0
1 0 0 0 2072 80972 111640 0 0 0 450 141 27 87 13
0
2 0 0 0 3024 80244 111356 0 0 0 1 108 25 99 1
0
0 0 0 0 30492 80244 86020 0 0 0 409 135 80 48 2
50

- Richard Huxton