writes "PostgreSQL 8.1 has been posted, though not officially announced as of this moment. This release includes two-phased commits, improved SMP and overall performance, a new role system replaces the older user/group, autovacuum is now within the backend rather than a separate contrib module, and various improvements, performance enhancements, and bugfixes. "
You can also read the developer notes
for the popular database. One thing is clear- with the newest Postresql and MySql, you have much to choose from.