Hello,I am testing Activiti framework from performance perspective. Actually I found problem with candidate tasks query performance if I have about 300 000 process instance in database. Problem is with this lines of code where I want to find out CANDIDATE tasks for concrete user:
org.activiti.engine.TaskService taskService = processEngine.getTaskService();
TaskQuery taskQuery = taskService.createTaskQuery();
taskQuery = taskQuery.taskCandidateUser(userId).orderByTaskCreateTime().asc();
List<org.activiti.engine.task.Task> list = taskQuery.listPage(0, MAX_TASKS_RESULTS);
This generates this DB select:
SELECT DISTINCT t. *
FROM act_ru_task t
INNER JOIN act_ru_identitylink i
ON i.task_id_ = t.id_
WHERE i.type_ = 'candidate'
AND i.group_id_ IN ( 'DISPATCHER' )
AND t.assignee_ IS NULL
ORDER BY t.create_time_ ASC
This query is executed about 8 seconds. I am using Activiti 5.9 with Oracle 11g database on Linux machines. All other queries are executed within milliseconds.I tried to found out where the problem is and it is with IS NULL condition in assignee_ column. If I changed condition in SQL to IS NOT NULL or = '1' the query is executed in milliseconds. So I realized that the problem is only with candidate tasks where assignee is not set (IS NULL).Do you have some solution to fix it?Thank you in advance.
