Hi!

Using jBPM 5.4.0 Final (but is similar for jBPM 6) we noticed that the REST API "/gwt-console-server/rs/tasks/{idRef}/participation" is pretty slow.

The called query is founded in jbpm-human-task-core-5.4.0.Final.jar in the file /META-INF/Taskorm.xml named "TasksAssignedAsPotentialOwnerByStatusWithGroups":

select
     new org.jbpm.task.query.TaskSummary(
     t.id,
     t.taskData.processInstanceId,
     name.text,
     subject.text,
     description.text,
     t.taskData.status,
     t.priority,
     t.taskData.skipable,
     actualOwner,
     createdBy,
     t.taskData.createdOn,
     t.taskData.activationTime,
     t.taskData.expirationTime,
     t.taskData.processId,
     t.taskData.processSessionId)
from
    Task t 
    left join t.taskData.createdBy as createdBy
    left join t.taskData.actualOwner as actualOwner
    left join t.subjects as subject
    left join t.descriptions as description
    left join t.names as name,
    OrganizationalEntity potentialOwners
where
    t.archived = 0 and
    ( potentialOwners.id = :userId or potentialOwners.id in (:groupIds) ) and
    potentialOwners in elements ( t.peopleAssignments.potentialOwners )  and
[...]

For users with a large numbers of tasks and groups the previous query takes very long time (in some cases also 2/3 minutes) to return (sometimes just few results).

Why don't apply directly a left join on t.peopleAssignments.potentialOwners instead of use OrganizationalEntity potentialOwners, removing "and potentialOwners in elements ( t.peopleAssignments.potentialOwners )" part?

The use of "OrganizationalEntity potentialOwners" is translated by Hibernate as a cross join.

Please let me know what do you think about that.

Thanks,

Francesco