RDBMS is an acronym for Relational Database Management System and this means software to make it possible to handle your structured data: Add, change, delete and search. Everybody on internet deals with it without knowing. For example your browser stores bookmarks (aka favorites) in a database. Can you do everything you want with it?
Theoreticaly the answer is yes given you have enough space and time. In practice the possibilties are limited. However using the cloud an almost unlimited amount of space is available. Processing power, internal memory, disks and other external media of many added together and cooperating i.e. file-sharing is a blessing of Web 2.0 and beyond, but the disadvantage is that so many people produce a huge amount of text in which searching becomes explosively complicated.
One of the solutions might be big data.