A database architecture includes at least an in-memory database and a disk-based database (also referred to as “hot” and “warm” data stores). In the database architecture, data can be partitioned (and re-partitioned) and/or moved within and among the in-memory and disk-based databases, based on query access patterns derived from received database queries. The partitions and inter-database movements can be based at least in part on clustered, dynamic data units that are defined using shared individual attribute values of data records, and updated based on the received queries.