Add indexes on span_status and dag_version_id in task_instance

[anandkaranubc]

closes: #53401

This PR adds two indexes to the task_instance table to improve query performance:

• idx_span_status on the span_status column
• idx_dag_version_id on the dag_version_id column

These indexes help speed up scheduler and DAG processor operations when the task_instance table has a large number of records (~10M+), as noted in issue #53401.

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[potiuk]

Well. You also need to change definition of the models - migrations generally should be generated as result of changes in the models as far as I understand.

[amoghrajesh]

Just linked the PR to the issue: closes: #53401

[AbhiSinha08]

I am working on adding the indexes manually on DB in my Airflow 3 instance since it is affecting DP performance. I am curious why we are having id as the first column in the index idx_span_status

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed in 5 days if no further activity occurs. Thank you for your contributions.

[potiuk]

@anandkaranubc We are unassigning you from this issue as part of our updated assignment policy.

This is not meant to discourage your contribution — quite the opposite! You are still very welcome to work on this issue and submit a PR for it. Simply comment that you are working on it and open a PR when ready.

We found that formal assignments were not working well, as they often prevented others from contributing when the assignee was not actively working on the issue.