poor performance of db-4.8.26?

Hi, I'm just testing performance of db-4.5.20 vs. db-4.8.26 and found that db-4.8.26 much slower than db-4.5.20.

BerkeleyDB: 4.5.20 real 0m4.973s user 0m2.043s sys 0m0.784s

BerkeleyDB: 4.8.26 real 0m7.461s user 0m2.517s sys 0m0.995s

The OS is openSuSE-11.1, I just built openldap-2.4.21 twice, using the same slapd.conf to setup two servers and slapadded some 30,000 dummy entries, the search was done on a subtree with 10,000 dummy entries. The script can be found here: http://pastebin.de/4428

In fact I tested filesystem performance as well, creating partions with ext3, ext4 and btrfs, but fould that these filesystems had almost no influence on performance, at least not with such a small database.

-Dieter