I was planning to use db4o for a website. It’s a microblog site with small posts and comments developed in Java.
The thing is I contacted db4o support asking if db4o would be suitable for a website, and they answered me that only for websites with low concurrency. That means with few requests?
So, now I think db4o will not be a good choice.
Do you know if there is any object database for Java suitable for a website?
Don’t use an Object database. Many projects based on them fail. Relational databases are proven on many projects, so use MySQL, H2, Derby, Oracle, or any other relational database that meets your needs.
If you want to try something new, use a Map-Reduce based store or a document based store like Hadoop, Cassandra, CouchDB, et al. http://nosql-database.org/