Wondering what you mean by "license to BigTable". BigTable is using GFS, so it will not be much use to Oracle without GFS. Also, since Google nicely described

Wondering what you mean by "license to BigTable". BigTable is using GFS, so it will not be much use to Oracle without GFS. Also, since Google nicely described some of the major ideas behind BigTable in a paper, there are few Open-Source implementations of it. I expect that like many database systems - getting a license is easier than building and maintaining a stable system :)