You might wish to visit the comparison of relational database management systems. There are tables showing comparative information for all the most popular relational databases.
Here is an excerpt: “The following tables compare general and technical information for a number of relational database management systems. Please see the individual products’ articles for further information. This article is not all-inclusive or necessarily up-to-date. Unless otherwise specified in footnotes, comparisons are based on the stable versions without any add-ons, extensions or external programs.”