TOP 1 WITH TIES

Today, SQL Server MVP Frank Kalis pointed to this interesting comparison by NGSSoftware . As per the study, the reported number of security flaws in Microsoft SQL server is near to zero for the period 0f 2005-2006, whereas the Oracle figures are going higher.

Here is the link.

Which database is more secure?Oracle vs. Microsoft

Update: There is another study emphasizing the fact at the Enterprize Strategy Group website.
Also see this comparison from Microsoft.