Performance Difference on UFS and ZFS

[Metin Döşlü]

Hi -

I installed PostgreSQL 9.1.6 on FreeBSD 9.0-RELEASE, and compared ZFS
to UFS. I also made sure all data easily fit into memory, ran some
sequential scan queries on the database.

Query run times on UFS were 100-200% slower than those of ZFS. This
was intriguing as all data came from memory. What could be causing
such a large performance difference?

Thanks,
Metin Döşlü