> Note that while the average hits/s between 100 and 500 is over 600 tps
> for
> Postgres there is a consistent smattering of plot points spread all the
> way
> down to 200 tps, well below the 400-500 tps that MySQL is getting.
Yes, these are due to checkpointing, mostly.
Also, note that a real forum would not insert 100 posts/s, so it would
not feel this effect. But in order to finish the benchmark in a correct
amount of time, we have to push on the inserts.
> Some of those are undoubtedly caused by things like checkpoints and
> vacuum
> runs. Hopefully the improvements that are already in the pipeline will
> reduce
> them.
I am re-running it with other tuning, notably cost-based vacuum delay and
less frequent checkpoints, and it is a *lot* smoother.
These take a full night to run, so I'll post more results when I have
usefull stuff to show.
This has proven to be a very interesting trip to benchmarkland...
