From PostgreSQL wiki
Benchw is a multidatabase benchmarking tool designed to be a very simple data warehousing application with a star schema. It's designed around ease of running its tests. The standard sizing recommendation for Benchw is to pick a scale such that the database is at least 2X the size of physical RAM in the server.
In 2004 it was used to compare PostgreSQL, MySQL, and Firebird as well as note performance changes from PostgreSQL 7.2 to 8.0. It was also used in some 2007 Sun benchmark tests featuring PostgreSQL, such as Solaris ZFS and Red Hat Enterprise Linux ext3 and Solaris ZFS and Microsoft Server 2003 NTFS.