Optimize task_reschedule_count query with EXISTS check#62062
Closed
manipatnam wants to merge 2 commits into
Closed
Optimize task_reschedule_count query with EXISTS check#62062manipatnam wants to merge 2 commits into
manipatnam wants to merge 2 commits into
Conversation
| session.scalar( | ||
| select(func.count(TaskReschedule.id)).where(TaskReschedule.ti_id == task_instance_id) | ||
| ) | ||
| or 0 |
Contributor
There was a problem hiding this comment.
This amounts to double queries. I think the right fix is adding index on the id which was done here: #61983
Contributor
Author
|
Closing this as index is added |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Optimize task_reschedule_count query with EXISTS check
For customers with huge number of TaskReschedule rows (from heavy sensor usage), the unconditional COUNT query on every task execution causes performance issues.
This PR adds an EXISTS check before the COUNT query. The EXISTS check returns instantly for tasks without reschedule records (99%+ of tasks), avoiding expensive operations on the TaskReschedule table. Sensors and tasks rescheduled due to DAG load failures still get accurate counts.
Performance impact: