Please consider adding this feature to PostgreSQL.
Use Case:
When deleting a large number of records with constraints and triggers PostgreSQL is exceptionally slow.
Suggested change:
I believe a way to speed this processes up would be to offer an option a user could “turn on” prior to doing the delete.
Example: set delete-no-roll-back=true
Now as PostgreSQL deletes rows it literally deletes them one at a time as though the user was only deleting a single row. This means that if cancel were executed on a delete action then it would only roll back the current row that PostgreSQL was in the process of deleting. Example: if you had 10 million row to delete and then pressed cancel after three minutes maybe 5 million are deleted.
You seem to be asking for an unlogged transaction, but that doesn't have anything to do with efficiently deleting rows.