If you are using Teradata Database 15.0 and later on SLES 11, you can limit the number of queries that can run concurrently in a particular virtual partition.
Virtual partitions are used to divide a system for a higher level of control over resource allocation and workload distribution. You can create virtual partitions and assign workloads to the partitions. Theoretically, one partition could use all the AWTs, rendering the other partitions useless. By creating a virtual partition throttle, you can ensure each partition is guaranteed access to the AWTs.
As with other throttles, you can specify virtual partition throttle limits for different states. The concurrency limit you define represents an aggregate number that applies to all queries in the partition.