I have a script that uses REXML to stream parse an XML file and load a 
MySQL database from it. The file is about 65000 lines, 2.2 MB. With Ruby 
1.8.0, it completes in about 25 seconds. I just installed Ruby 1.8.1, 
and the performance is at least a factor of 20 worse.

This is on a 1 GHz P3 running Gentoo Linux. I don't have head-to-head 
comparison numbers, but I'm observing the same effect on a 3.2 GHz P4 
running RedHat 9. The script runs for 16 minutes when it should have 
completed in a few seconds.

I've commented out the database calls, so I'm just measuring the 
Ruby/REXML performance.

Any ideas?