Just Oracle and IBM?

Something seems wrong with this journalism:

"A report by Gartner Group showed that Oracle has 81 percent market share of Linux relational database software in 2004 compared to IBM’s 17 percent."

What? Is only 2% of all Linux users using MySQL, PostgreSQL, Firebird, Ingres, Interbase or MaxDB? (see: a longer list of more obscure linux relational databases)

Ok, let's turn it around. Perhaps they only mean paid-for relational databases. Can it still mean that only 2% of all relational databases on Linux are completely free??