If we assume that people are buying books because of a market demand, we see Oracle is steep decline and SQL Server book sales up 83%, followed closely by PostgreSQL. We saw this exact same trend in 1992-1995 when Oracle books started to dominate the database book market, displacing DB2 and IDMS/R books.
As a whole, the big news is that database book sales are way-down with the exception of PostgreSQL and SQL Server books, which are up 83% and are now double the size of the Oracle market.
Check out Donald Burleson’s full article
Some of this shift may be due to the recent release of Microsoft SQL Server 2005. Dispite it’s small overall percentage, the growth in PostgreSQL book sales is significant enough to keep an eye on it in the near future.
Also interesting is the stagnation of the MySQL book sales, down 2% from last year. With the number of blogs, wikis and other relatively hot technologies running on MySQL I’m surprised this number is down.
In contrast to the book sales, Alexa, which measures a number of statistics to determine rank among web pages, shows increased web ranking for Oracle, MySQL and PostgreSQL, while showing decreased traffic to Microsoft’s corporate site.