I am entering a project to make a Opinion Mining (Data Mining -> Web Mining -> Opinion Mining) to get semantic orientation of the words contained. We will use a crawler to get the pages opinion. Now the question is, what type of DataBase should I use (OO, Relational, hierachycal, etc), is best to use in this type of project. I know this is a specific question, Im not expecting everybodies response but at least someone that already did it, that would help.
Regards!
On
From my experience in such kind of scenarios a relational database can serve your purpose pretty well. You need to be extra careful when storing the web content part of it - whether you want to at all use a database to store it or will storing on as simple as a file system can do. BLOBs specially require extra care and they increase your maintenance work.
Also based on the nature of the project, you would certainly be using a lot of already built in components etc. many of which would already support/easy to extend to use a relational DB as a data store.
If you need something large scale and responsive, you would probably need to go for Google's BigTable or something of that nature. At the prototype level, I am sure you can use traditional relational databases, but at certain point you'd hit the performance wall. See Brewer's CAP Theorem.