I came across this article today, which talks about non-RDBMS solution for data storage (or a fancy name, data persistent layer).
It’s a great start point – I’ve been thinking about non-RDBMS solution for a while, but other than LDAP I don’t have anything else in my mind (weird enough, seems LDAP is not in the list, maybe it’s just too old to be “new tech”).
I will try out those projects mentioned in the article, and will post some data here if I get anything.