A very long time ago, we wrote an article on how to use PostgreSQL to show the fully qualified name of an item in an inventory tree.
Basically we were modeling a paper products tree. The original article can be found here Using PostgreSQL User-Defined Functions to solve the Tree Problem and was based on PostgreSQL 7.4 technology.
We'll repeat the text here for completeness and demonstrate the PostgreSQL 8.4 that solves this and more efficiently.
Comparison of PostgreSQL 8.4, Microsoft SQL Server 2008, MySQL 5.1
In our May 2008 issue of Postgres OnLine Journal, we cross compared Microsoft SQL Server 2005, MySQL 5, and PostgreSQL 8.3.
Some people mentioned well since 8.4 has now come out, shouldn't we go back and update the reference. We deliberated and decided not to.
To be fair all 3 products have released new versions, so it would seem unfair to compare a newer PostgreSQL against older versions of MS SQL Server and MySQL.
We have therefore decided to repeat our exercise and include parts people felt we should have covered, as well as comparing the latest and greatest stable release of each product.
People ask us time and time again what's the difference why should you care which database you use. We will
try to be very fair in our comparison. We will show equally how PostgreSQL sucks compared to the others. These are the items we
most care about or think others most care about. There are numerous other differences if you get deep into the trenches of each.