Jeremy Kerr wrote:
>> Speaking of which, what about some performance numbers?
>
> OK, benchmarks done:
>
> http://ozlabs.org/~jk/projects/db/data/postgres.bcTruelen/
>
> Summary: small increase in performance (~1-2% on my machine), at about
> 1.5 standard deviations from the mean. Profiles show a decent drop in
> hits within bcTruelen.
>
> However: Sysbench seems to be quite heavy with the fixed-width char
> types, so may end up calling bcTruelen more than most workloads. Would
> be nice to get some x86 numbers too, but I don't have a suitable machine
> here.
>
> So: The increase in performance is positive on this workload, albeit
> fairly minor. Downside is increased code complexity.
Based on this benchmark, I don't think this patch is worth it..
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com