PostgreSQL 9.2 benchmarks

Hi,

I took advantage of an available dual-Xeon box to do some scalability
benchmarking.

I used Pgbench and PostgreSQL-9.2beta3. PostgreSQL 9.2.x has improved
scalability and should now scale up to 64 cores.

The actual hardware used two Xeons X5650 and 24GB RAM, for a total number
of 12 cores and 24 threads.

I compared the performance of various operating systems:
- Scientific Linux 6.2
- FreeBSD 9.1-RC1
- NetBSD 6.0-BETA2
- DragonFly 3.0
- DragonFly 3.1

I also compared some topology scheduling targets:
- no topology awareness
  (DragonFly 3.1 before the new scheduler work was pushed)
- processes stick on cpu threads
- processes stick on cpu sockets

Results with graphs are in the attached PDF file.

Some rapid conclusions:
- Scientific Linux smokes all other operating systems
- DragonFly and FreeBSD performance is mostly the same, FreeBSD degrades
  faster under high loads
- NetBSD has trouble handling high numbers of database clients but still
  manages to scale when numbers are low
- Keeping processes on the same location they last ran on increases
  performance by a few percents

-- 
Francois Tigeot