uses Oracle and MySQL http://www.oracle.com/technology/pub/articles/gibson-xe-googleearth.html http://www.mysql.com/why-mysql/
Must be Oracle, modified version of Oracle, because: 1: Oracle is most powerful 2: If Google designed them own database, there's no reason they are not sell it.
What a joke! Typical newbie comments! As other members said, Google use Oracle and MySQL - of course they are modified. Every large company use modified OS, modified database and other applications according to their requirements. That's why Open Source Community can exists fighting against corporate gaints like Microsoft.
I don't think he meant "big tables" for describing the size of the tables, but "bigtable" (http://labs.google.com/papers/bigtable.html).
Big table !!! Its their own database. But atlast all database queries and all is same !!! so no worry guyssss sybase,oracle can do it