Scalability Considerations for Tactical Queries
Scalability Is a Relative Concept
In traditional decision support applications, setting the stage for scalable performance with Teradata Database involves distributing the work equally across all the AMPs in the system. As more nodes are added to a system, the number of AMPs increases proportionally, and the effort to process a complex query is spread across more parallel units, reducing response times. The following plot indicates linear scalability, graphing the total workload accomplished as a function of the number of nodes in the system. Strategic queries run proportionally faster as more nodes are added to a system.
Spreading the data evenly across all AMPs remains the goal of designing the database to support tactical queries. But to achieve the type of scalability that best supports tactical queries, you need to localize the work in such a way that it accesses only a few rows using the least resources possible. This means accessing the smallest number of AMPs possible to perform an operation; optimally only one. The following figure indicates that when tactical queries access only a few AMPs, more of them can run concurrently.