@NamedQueries( { @NamedQuery(name = CallTimeDataKey.QUERY_DELETE_BY_RESOURCES, query = "DELETE CallTimeDataKey ctdk WHERE ctdk.schedule IN ( SELECT ms FROM MeasurementSchedule ms WHERE ms.resource.id IN ( :resourceIds ) )") })

forces the database into full table scans per resource id deleted (actually, only one resource id is passed in, but this does not matter here).


Putting an index on rhq_calltime_data_value.key_id speeds up the deletion dramatically (from multiple minutes in my case to several seconds)


CREATE INDEX ct_key_index
  ON rhq_calltime_data_value
  USING btree
  (key_id);