This should be some kind od dictionary. As I wrotte in my original post. Data structure of stored value is hash of array of objects.

Currently only working solution is Tie::RDBM with PostgreSQL database backend. Trying to save data in memory I can't share whole hash which contain values as I described before. Because all server threads must be able to add / delete / modify this data I'm currently looking on solutions based on Tie::RDBM + PostgreSQL and MLDBM + BerkeleyDB. When BerkeleyDB with MLDBM is used I get some strange errors probably originaly from Storable module - 'inbalid byte order', 'wrong signature' or 'bad data'...

Other problem I have with tied hashes and Storable (not solved yet) was described in node Storable: where is my memory?.