Performance comparison for bdb/fsfs and svn/svk

While doing a new round of simple benchmarking, I found some interesting figures:

** bdb
*** svk checkout - 24 sec
*** svn export - 38 sec
*** svn checkout - 73 sec

** fsfs
*** svk checkout - 28 sec
*** svn export - 25 sec
*** svn checkout - 85 sec

The tests are run against the mirrored subversion trunk (+8300 revs),
on an idling Pentium III-500 with FreeBSD 5.2-CURRENT.

Tests are ran numerous times, and use the average of the real time of
those 3 runs with higher CPU throughput. This is to see how good the
backend could let the OS cache the IO - though repeated
checkout/export is not generally the use case.

While fsfs was expected to be slower than bdb on constructing out head
rev, repeated runs make it faster on export but not checkout.

Cheers,
CLK