The Throttles view on the ruleset toolbar allows you to control the concurrent queries by state or other criteria. A throttle limits the number of user queries that can be active at the same time based on a specified number, the query request source, target, or other query characteristics you select. When the throttle limit is reached, you can specify that new queries are placed in a delay queue or rejected.
In general, use throttles to control the number and types of query requests that you want processed and use the state matrix to indicate under which conditions you want certain limits to apply. For example, you can create a throttle to:
- Limit a specific user to running no more than 10 queries at a time.
- Limit a specific department to no more than 4 simultaneous queries.
- Limit a Base state to run 12 concurrent queries but allow a Midnight state to run an unlimited number.
- Limit queries from a specific request source, such as a load utility, to a specific target, such as a database or a table.
- Limit queries based on statement type, step row count, join properties, and more.
The following tabs in the Throttles view display throttle information for a ruleset from different perspectives:
- Throttles
- List of all the throttles, their status, and classification criteria. You can click a throttle name to drill down to detailed information about the throttle or to change its properties. These are several types of throttles:
- System Throttles limit the number of concurrent queries running on a Teradata Database system.
- Virtual Partition Throttles limit the number of concurrent queries running on a virtual partition.
- Workload Group Throttles limit the total number of concurrent queries allowed for all workloads in a specified group. Only workloads with delay throttles defined in the Workloads view can be added to a workload group throttle. Workload group throttles are available in Teradata Database 14.10 and later.
- Workloads with Throttles Defined limit the number of concurrent queries for an individual workload.
- Throttle Limits by State
- List of all the states to which specific throttles are applied. The FLEX attribute is displayed for workloads that have flex throttles enabled for a state.
- Resource Limits
- List of all the resource limits, their status, and classification criteria. You can click a resource limit name to drill down to detailed information or to change its properties.
- Resource Limits by State
- Lists the system default AWT resource limits, and the maximum percentage of AWTs available for each limit rule in each state. The lowest applicable limit shown in either section is enforced.