Re: Insert Performance with WAL and Fsync

Mike Schroepfer <mike@raplix.com> writes:
> b.1) 32tps 7.1.2 on the dual processor box again
> b.2) 31tps 7.2 tip of cvs on the dual processor box

> So 7.2 doesn't appear to help.

Mmm, yeah, I missed that you were only looking at the single-client
case; so the extra CPU has nothing to do anyway, and there's no spinlock
contention to cause a problem.  Most of the work we've been doing for
7.2 was concerned with improving multi-client performance.  But still,
seems odd that you can't do better than 32 tps on this setup.

> b.3) output of vmstat 5 during b.1:

> procs     memory            page            disk          faults      cpu
>  r b w   swap  free  re  mf pi po fr de sr s0 s1 s6 --   in   sy   cs us sy
> id
>  0 0 0 2140760 1820952 2 15  1  1  1  0  0  2  0  0  0  430  130   71  1  1
> 99
>  0 0 0 2093696 1690392 15 128 0 91 91 0  0 128 0  0  0 1232 1886  894 11  3
> 86

What are the "disk" numbers in this variant of vmstat?  Given the low
CPU usage, one would hope that your disk is going flat out ... but if
128 is page transfers per second, it's not very impressive...

            regards, tom lane