Add a federated index to resolve mongo slow queries (#5818)

* Add a new cron function

* Add a new cron function

* set the milestone

* Adding a union index speeds

* Update execution_queue.py

* Update execution_queue.py

* Update execution_queue.py

* Update CHANGELOG.rst

* Update execution_queue.py

* Update st2common/st2common/constants/triggers.py

* Update CHANGELOG.rst

* Reformat with black

Co-authored-by: Eugen C <1533818+armab@users.noreply.github.com>

Author: chain312

CHANGELOG.rst

@@ -16,6 +16,8 @@ Added
   #5778 #5789 #5817 #5795 #5830 #5833 #5834 #5841 #5840 #5838 #5842 #5837 #5849 #5850
   Contributed by @cognifloyd
 
+* Added a joint index to solve the problem of slow mongo queries for scheduled executions. #5805
+
 
 3.8.0 - November 18, 2022
 -------------------------

st2common/st2common/models/db/execution_queue.py

@@ -77,6 +77,11 @@ class ActionExecutionSchedulingQueueItemDB(
             {"fields": ["liveaction_id"], "name": "lv_ac_id"},
             {"fields": ["original_start_timestamp"], "name": "orig_s_ts"},
             {"fields": ["scheduled_start_timestamp"], "name": "schd_s_ts"},
+            # Adding a union index speeds up the query action_execution_scheduling_queue_item_d_b
+            {
+                "fields": ["scheduled_start_timestamp", "original_start_timestamp"],
+                "name": "schd_orig_s_ts",
+            },
         ]
     }