If a query requests additional memory and is denied, the query fails with an out of memory error and an alert is raised.
Greenplum Database has two ways to manage memory resources: resource queues and resource groups. Resource queues deal primarily with fixed quantities of memory, where resource groups deal with portions—percentages—of available memory.
If you use resource groups to manage memory, you can use the Workload Mgmt view to adjust them so that more memory is available to queries that are failing due to out of memory errors. If you use resource queues, you use the
CREATE RESOURCE QUEUE and
ALTER RESOURCE QUEUE SQL commands to configure them.
There are many factors to consider when allocating memory for queries, including configuring the operating system, allocating a share of memory to Greenplum Database, and configuring a set of resource queues or resource groups to share the memory available to Greenplum Database.
For complete information about how Greenplum Database manages memory and how to configure it, see: