Doru wrote: I once created a simple model for a distributed ram-based OLAP system. That had independent nodes, connected to a network with known delay and speed, and simple read-only queries. Queries would just take some space, move (and split-join) from node to node and increase their timestamps. For a sql database just start adding complex queries, write locks, limited buffer sizes, cpu cores & caching and disks... Not so easy. Stephan