There is Class::XPath, which allows you to graft XPath queries onto almost any class structure. Also, there is Data::Diver, which has its own query "language" to access elements without autovivification. Using a database incurs a lot of front-up work which may or may not pay off in the long run, as for every addition to the data format, the SQL schema needs to be modified. LDAP seems more suited for storing unstructured or semistructured hierarchical data.