pankajkoti opened a new pull request, #39526:
URL: https://github.com/apache/airflow/pull/39526
When the dag records count gets huge, and users try to delete
DAG and DAG runs that are no longer needed or are stale, it
is observed that the deletion is significantly slow. The reason
for this is that the CASCADING DELETES are slow. Although,
we have foreign key constraints in the referencing tables, they
do not create an index implicitly on those columns (dag_id in
the referencing tables in this case). Hence, we're creating indexes
on the 6 referencing table for CASCADE DELETES to speed up
the deletion of records. Without these indexes, it was observed
that it takes many hours to delete those records and it reduced
to a few seconds after adding those indexes.
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