Gene <genekhart@gmail.com> writes:
> I was curious to see how postgres would perform with wal on a tmpfs vs disk
> here are some numbers I got from pgbench. Let me know if I did something
> stupid, this is the first time I've used pgbench. The wal on tmpfs method is
> not significantly faster.
This comparison is not very useful because you were using battery-backed
write cache, which gives pretty much all the performance improvement
that is to be looked for in this area. Try it against a plain vanilla
disk drive (that's not lying about write complete) and you'll find the
maximum TPS rate is closely related to the disk's rotation rate.
At the same time though, the existence of BBWC solutions makes me wonder
why we need another.
regards, tom lane