Ranking of database engines

So it is January again and it is time for various trend reports and market share.

Portal db-engines.com publishes, among other interesting content, periodic reports showing popularity of DBMS engines on the market. There is a number of factors taken into account, best described here. It is important to know that the report does not show the relative share of particular DBMS on the market, but rather its popularity among developers really.

What is striking though, that there are three leading technologies in terms of popularity - Oracle, MySQL and SQL Server. They are quite close to each other and quite apart from the fourth one - PostgreSQL.

When you look at the historical trends chart, you can see that the position of the top three has been strong in the past, and it does not seem to be in grave jeopardy any time soon.

What do you think about this ranking?