Transaction processing systems are generally considered easier to scale than data warehouses. Relational databases were designed for this type of workload, and there are no esoteric hardware requirements. Mostly, it is just matter of normalizing to the right degree and getting the indexes right. The major challenge in these systems is their extreme concurrency, which means that small temporary slowdowns can escalate to major issues very quickly.
In this presentation, Gwen Shapira will explain how application developers and DBAs can work together to built a scalable and stable OLTP system - using application queues, connection pools and strategic use of caches in different layers of the system.