Performance of historical PostgreSQL releases
In November of 2005, PostgreSQL 8.1 was released. It included a number of internal architectural changes, some of which aimed to improve how fast the database would run on a multi-processor system with many active clients. The result was a major improvement in the ability of the database to scale upwards to handle a heavy load. Benchmarks on modern hardware really highlight just how far that version leapfrogged earlier ones. You can find an excellent performance comparison of versions 8.0 through 8.4 from György Vilmos at http://suckit.blog.hu/2009/09/29/postgresql_history. This shows exactly how dramatic these improvements have been. These tests use the Online Transaction Processing (OLTP) test of the sysBench benchmarking software, available at http://sysbench.sourceforge.net/.
This test gives a transactions per second (TPS) figure that measures the total system speed, and you can run it in either a read-only mode or one that includes...