Workload Management

This section explains how you can use Priorities and Schema Quotas in Exasol to manage the workload and distribute the resources among the users.


By the use of priorities, Exasol resources can be systematically distributed across users and roles. By default, the sessions of all users have the same priority. If you want to influence the execution of many parallel queries, you can chose between the priority groups LOW, MEDIUM, and HIGH which can be assigned via GRANT statement.

Users within one group share these resources (CPU and RAM) equally. If the default priority groups are not enough for your requirements, Exasol provides the possibility to adjust them appropriately by creating, altering, dropping them, or by adjusting their weights. Priorities can be useful if you connect a web application which has low latency requirements, and your system frequently has to process 10 or more parallel queries. On the other side, long running ETL processes or queries from less important applications could get a lower priority. For more information, see Priorities.

Schema Quotas

To limit the data volume in your system or the volume for certain tenants, it's possible to use the concept of schema quotas. You can specify the maximum raw data size for a schema (the raw size of all contained data objects). By default, the raw data sizes for schemas are unlimited. You can define the limit through ALTER SCHEMA command . The corresponding raw data sizes for objects is available in the system table EXA_ALL_OBJECT_SIZES. The value NULL means unlimited. If the limit of a schema is exceeded, users will get an error message during the commit when trying to insert additional data.