System throttles are a widely used workload management functionality that allow administrators to limit concurrency of queries entering the database based on specified characteristics of the query. System throttles only work on primary clusters. A system filter rejects queries before the query begins execution, based on information contained within the optimized plan of the query or session logon details (tables accessed, user, IP address, and so on).
Additional system throttles can be used to make sure that only a few resource-intensive queries execute at the same time, so more resources are available for shorter and more business-critical applications. System throttles are useful to control concurrency of queries performing advanced analytics or accessing external object storage data through the Native Object Store feature, where lower concurrency moderates resource demands.
See Workload Management: Ruleset APIs for information on applying APIs and implementation examples.